Canadian Patents Database / Patent 2764282 Summary

Third-party information liability

Some of the information on this Web page has been provided by external sources. The Government of Canada is not responsible for the accuracy, reliability or currency of the information supplied by external sources. Users wishing to rely upon this information should consult directly with the source of the information. Content provided by external sources is not subject to official languages, privacy and accessibility requirements.

Claims and Abstract availability

Any discrepancies in the text and image of the Claims and Abstract are due to differing posting times. Text of the Claims and Abstract are posted:

  • At the time the application is open to public inspection;
  • At the time of issue of the patent (grant).
(12) Patent: (11) CA 2764282
(54) English Title: HYDROCARBON GAS PROCESSING
(54) French Title: TRAITEMENT DE GAZ D'HYDROCARBURES
(51) International Patent Classification (IPC):
  • F25J 3/00 (2006.01)
  • C10L 3/10 (2006.01)
  • F25J 5/00 (2006.01)
(72) Inventors :
  • JOHNKE, ANDREW F. (United States of America)
  • LEWIS, W. LARRY (United States of America)
  • WILKINSON, JOHN D. (United States of America)
  • LYNCH, JOE T. (United States of America)
  • HUDSON, HANK M. (United States of America)
  • CUELLAR, KYLE T. (United States of America)
(73) Owners :
  • S.M.E. PRODUCTS LP (Not Available)
(71) Applicants :
  • ORTLOFF ENGINEERS, LTD. (United States of America)
  • S.M.E. PRODUCTS LP (United States of America)
(74) Agent: GOWLING WLG (CANADA) LLP
(74) Associate agent:
(45) Issued: 2016-01-05
(86) PCT Filing Date: 2010-03-31
(87) Open to Public Inspection: 2010-12-16
Examination requested: 2015-03-26
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country/Territory Date
61/186,361 United States of America 2009-06-11
12/689,616 United States of America 2010-01-19
12/717,394 United States of America 2010-03-04

English Abstract





A process and an apparatus are disclosed for the recovery of propane,
propylene, and heavier hydrocarbon components
from a hydrocarbon gas stream in a compact processing assembly. The gas stream
is cooled, expanded to lower pressure,
and supplied as the bottom feed to an absorbing means inside the processing
assembly. A first distillation liquid stream is collected
from the lower region of the absorbing means and supplied as the top feed to a
mass transfer means inside the processing assembly.
A first distillation vapor stream is collected from the upper region of the
mass transfer means and cooled sufficiently to at
least partially condense it, forming a residual vapor stream and a condensed
stream. The condensed stream is supplied as the top
feed to the absorbing means. A second distillation vapor stream is collected
from the upper region of the absorbing means and directed
into one or more heat exchange means inside the processing assembly to heat it
while cooling the first distillation vapor
stream. The heated second distillation vapor stream is combined with any of
the residual vapor stream and the combined stream is
directed into the one or more heat exchange means inside the processing
assembly to heat it while cooling the gas stream. A second
distillation liquid stream is collected from the lower region of the mass
transfer means and directed into a heat and mass transfer
means inside the processing assembly to heat it and strip out its volatile
components. The quantities and temperatures of the
feeds to the absorbing means are effective to maintain the temperature of the
upper region of the absorbing means at a temperature
whereby the major portions of the desired components are recovered in the
stripped second distillation liquid stream.




French Abstract

L'invention concerne un procédé et un dispositif permettant de récupérer du propane, du propylène et des composants hydrocarbonés plus lourds à partir d'un flux gazeux hydrocarboné dans un ensemble de traitement compact. Le flux gazeux est refroidi, dilaté à une pression inférieure et fourni comme charge de fond à des moyens d'absorption prévus dans l'ensemble de traitement. Un premier flux liquide de distillation est collecté à partir de la région inférieure des moyens d'absorption et fourni comme charge supérieure à des moyens de transfert de masse prévus dans l'ensemble de traitement. Un premier flux de vapeur de distillation est collecté à partir de la région supérieure des moyens de transfert de masse et refroidi suffisamment pour être au moins partiellement condensé, de manière à former un flux de vapeur résiduel et un flux condensé. Le flux condensé est fourni comme charge supérieure des moyens d'absorption. Un deuxième flux de vapeur de distillation est collecté à partir de la région supérieure des moyens d'absorption et dirigé dans un ou plusieurs moyens d'échange de chaleur prévus dans l'ensemble de traitement afin d'être chauffé, pendant que le premier flux de vapeur de distillation est refroidi. Le deuxième flux de vapeur de distillation est combiné à n'importe quel flux de vapeur résiduel, et le flux combiné est dirigé dans un ou plusieurs moyens d'échange de chaleur prévus dans l'ensemble de traitement afin d'être chauffé pendant que le flux gazeux est refroidi. Un deuxième flux liquide de distillation est collecté à partir de la région inférieure des moyens de transfert de masse et dirigé dans des moyens de transfert de chaleur et de masse prévus dans l'ensemble de traitement afin d'être chauffé et d'en extraire les composants volatils. Les quantités et les températures des charges appliquées aux moyens d'absorption permettent de maintenir la température de la région supérieure des moyens d'absorption à une température à laquelle la majeur partie des constituants voulus sont récupérés dans le deuxième flux liquide de distillation épuisé.


Note: Claims are shown in the official language in which they were submitted.

IN THE CLAIMS:
1. A process for the separation of a gas stream containing
methane, C2
components, C3 components, and heavier hydrocarbon components into a volatile
residue gas
fraction and a relatively less volatile fraction containing a major portion of
said C3 components
and heavier hydrocarbon components wherein
(1) said gas stream is cooled in a first heat exchange means housed in
a single equipment item processing assembly;
(2) said cooled gas stream is expanded to lower pressure whereby it is
further cooled;
(3) said expanded cooled gas stream is supplied as a bottom feed to an
absorbing means housed in said processing assembly;
(4) a first distillation liquid stream is collected from a lower region of
said absorbing means and supplied as a top feed to a mass transfer means
housed in said
processing assembly;
(5) a first distillation vapor stream is collected from an upper region of
said mass transfer means and cooled sufficiently to condense at least a part
of it in a second heat
exchange means housed in said processing assembly, thereby forming a condensed
stream and a
residual vapor stream containing any uncondensed vapor remaining after said
first distillation
vapor stream is cooled;
(6) at least a portion of said condensed stream is supplied as a top feed
to said absorbing means;
-28-

(7) a second distillation vapor stream is collected from an upper region
of said absorbing means and heated in said second heat exchange means, thereby
to supply at
least a portion of the cooling of step (5);
(8) said heated second distillation vapor stream is combined with any
said residual vapor stream to form a combined vapor stream;
(9) said combined vapor stream is heated in said first heat exchange
means, thereby to supply at least a portion of the cooling of step (1), and
thereafter discharging
said heated combined vapor stream from said processing assembly as said
volatile residue gas
fraction;
(10) a second distillation liquid stream is collected from a lower region
of said mass transfer means and heated in a heat and mass transfer means
housed in said
processing assembly, thereby to simultaneously strip the more volatile
components from said
second distillation liquid stream, and thereafter discharging said heated and
stripped second
distillation liquid stream from said processing assembly as said relatively
less volatile fraction;
and
(11) the quantities and temperatures of said feed streams to said
absorbing means are effective to maintain the temperature of said upper region
of said absorbing
means at a temperature whereby the major portions of the components in said
relatively less
volatile fraction are recovered.
2. The process according to claim 1 wherein
(a) said gas stream is cooled sufficiently to partially
condense it in
said first heat exchange means;
-29-

(b) said partially condensed gas stream is supplied to a separating
means and is separated therein to provide a vapor stream and at least one
liquid stream;
(c) said vapor stream is expanded to lower pressure whereby it is
further cooled;
(d) said expanded cooled vapor stream is supplied as the bottom feed
to said absorbing means;
(e) said at least one liquid stream is expanded to said lower pressure;
and
said expanded at least one liquid stream is heated in said first heat
exchange means, thereby to supply at least a portion of the cooling of step
(a), and thereafter
supplying said heated expanded at least one liquid stream as a bottom feed to
said mass transfer
means.
3. The process according to claim 1 wherein
(a) the first distillation liquid stream is collected from the lower region

of said absorbing means and heated in further heat exchange means, with said
heated first
distillation liquid stream thereafter supplied as the top feed to said mass
transfer means; and
(b) the first distillation vapor stream is collected from an upper region
of said mass transfer means and cooled sufficiently to condense at least a
part of it in said further
heat exchange means, thereby to supply at least a portion of the heating of
step (a), and thereby
forming said condensed stream and said residual vapor stream.
4. The process according to claim 3 wherein
-30-

(i) said gas stream is cooled sufficiently to partially condense it in
said first heat exchange means;
(ii) said partially condensed gas stream is supplied to a separating
means and is separated therein to provide a vapor stream and at least one
liquid stream;
(iii) said vapor stream is expanded to lower pressure whereby it is
further cooled;
(iv) said expanded cooled vapor stream is supplied as the bottom feed
to said absorbing means;
(v) said at least one liquid stream is expanded to said lower pressure;
and
(vi) said expanded at least one liquid stream is heated in said first heat
exchange means, thereby to supply at least a portion of the cooling of step
(i), and thereafter
supplying said heated expanded at least one liquid stream as a bottom feed to
said mass transfer
means.
5. The process according to claim 1 wherein
(a) said gas stream is partially cooled in said first heat exchange
means;
(b) said partially cooled gas stream is divided into first and second
portions;
(c) said first portion is further cooled in a heat and mass transfer
means housed in a separating means, thereby to simultaneously condense any
less volatile
components from said first portion;
-31-

(d) said second portion is further cooled in said first heat exchange
means;
(e) said further cooled first portion and said further cooled second
portion are combined to form the cooled gas stream;
(f) the first distillation liquid stream is collected from
the lower region
of said absorbing means and heated in the heat and mass transfer means housed
in the separation
means, thereby to supply at least a portion of the cooling of step (c), with
said heated first
distillation liquid stream thereafter is supplied as the top feed to the mass
transfer means; and
(g) the combined vapor stream is heated in said first heat
exchange
means, thereby to supply at least a portion of the cooling of steps (a) and
(d), and thereafter
discharging said heated combined vapor stream from said processing assembly as
said volatile
residue gas fraction.
6. The process according to claim 5 wherein
(a) said further cooled second portion is directed to said separating
means so that any liquids condensed as said first portion is further cooled
and as said second
portion is further cooled are combined to form at least one liquid stream,
with the remainder of
said further cooled first portion and said further cooled second portion
forming a vapor stream;
(b) said vapor stream is expanded to lower pressure whereby it is
further cooled;
(c) said expanded cooled vapor stream is supplied as the bottom feed
to said absorbing means housed in said processing assembly;
(d) said at least one liquid stream is expanded to said lower pressure;
-32-

(e) said expanded at least one liquid stream is heated in
said first heat
exchange means, thereby to supply at least a portion of the cooling of step
(1), and thereafter
supplying said heated expanded at least one liquid stream as a bottom feed to
said mass transfer
means; and
(f) the second distillation liquid stream is collected from
a lower
region of said mass transfer means and heated in the heat and mass transfer
means housed in said
processing assembly, thereby to simultaneously strip the more volatile
components from said
second distillation liquid stream, and thereafter discharging said heated and
stripped second
distillation liquid stream from said processing assembly as said relatively
less volatile fraction.
7. The process according to claim 5 wherein
(i) said first portion is further cooled in a third heat
exchange means;
and
(ii) the first distillation liquid stream is collected from
the lower region
of said absorbing means and heated in said third heat exchange means, thereby
to supply at least
a portion of the cooling of step (i), with said heated first distillation
liquid stream thereafter
supplied as the top feed to the mass transfer means.
8. The process according to claim 7 wherein
(a) said further cooled first portion and said further cooled second
portion are combined to form a partially condensed gas stream;
(b) said partially condensed gas stream is supplied to a separating
means and is separated therein to provide a vapor stream and at least one
liquid stream;
-33-

(c) said vapor stream is expanded to lower pressure whereby it is
further cooled;
(d) said expanded cooled vapor stream is supplied as a bottom feed to
said absorbing means;
(e) said at least one liquid stream is expanded to said lower pressure;
and
(f) said expanded at least one liquid stream is heated in
said first heat
exchange means, thereby to supply at least a portion of the cooling of step
(1), and thereafter
supplying said heated expanded at least one liquid stream as a bottom feed to
said mass transfer
means.
9. The process according to claim 3 wherein said second heat exchange
means is housed in said processing assembly.
10. The process according to claim 4 wherein said second heat exchange
means is housed in said processing assembly.
11. The process according to claim 2 wherein said separating means is
housed
in said processing assembly.
12. The process according to claim 4, 8, or 10 wherein said separating
means
is housed in said processing assembly.
13. The process according to claim 5 or 6 wherein said separating means is
housed in said processing assembly.
14. The process according to claim 3, 7, or 9 wherein
-34-

(1) said heated first distillation liquid stream is supplied to said mass
transfer means at an intermediate feed position;
(2) said condensed stream is divided into at least first and second
reflux streams;
(3) said first reflux stream is supplied as said top feed to said
absorbing means; and
(4) said second reflux stream is supplied as said top feed to said mass
transfer means.
15. The process according to claim 4, 8, or 10 wherein
(1) said heated first distillation liquid stream is supplied to said mass
transfer means at an intermediate feed position;
(2) said condensed stream is divided into at least first and second
reflux streams;
(3) said first reflux stream is supplied as said top feed to said
absorbing means; and
(4) said second reflux stream is supplied as said top feed to said mass
transfer means.
16. The process according to claim 5 or 6 wherein
(1) said heated first distillation liquid stream is supplied to said mass
transfer means at an intermediate feed position;
(2) said condensed stream is divided into at least first and second
reflux streams;
-35-

(3) said first reflux stream is supplied as said top feed to said
absorbing means; and
(4) said second reflux stream is supplied as said top feed to said mass
transfer means.
17. The process according to claim 12 wherein
(1) said heated first distillation liquid stream is supplied to said mass
transfer means at an intermediate feed position;
(2) said condensed stream is divided into at least first and second
reflux streams;
(3) said first reflux stream is supplied as said top feed to said
absorbing means; and
(4) said second reflux stream is supplied as said top feed to said mass
transfer means.
18. The process according to claim 13 wherein
(1) said heated first distillation liquid stream is supplied to said mass
transfer means at an intermediate feed position;
(2) said condensed stream is divided into at least first and second
reflux streams;
(3) said first reflux stream is supplied as said top feed to said
absorbing means; and
(4) said second reflux stream is supplied as said top feed to said mass
transfer means.
-36-

19. The process according to claim 1 wherein
(1) A gas collecting means is housed in said processing assembly;
(2) an additional heat and mass transfer means is included inside said
gas collecting means, said additional heat and mass transfer means including
one or more passes
for an external refrigeration medium;
(3) said cooled gas stream is supplied to said gas collecting means and
directed to said additional heat and mass transfer means to be further cooled
by said external
refrigeration medium; and
(4) said further cooled gas stream is expanded to said lower pressure
and thereafter supplied as said bottom feed to said absorbing means.
20. The process according to claim 14 wherein
(1) A gas collecting means is housed in said processing assembly;
(2) an additional heat and mass transfer means is included inside said
gas collecting means, said additional heat and mass transfer means including
one or more passes
for an external refrigeration medium;
(3) said cooled gas stream is supplied to said gas collecting means and
directed to said additional heat and mass transfer means to be further cooled
by said external
refrigeration medium; and
(4) said further cooled gas stream is expanded to said lower pressure
and thereafter supplied as said bottom feed to said absorbing means.
21. The process according to claim 2, 4, 8, 9, 10, or 11 wherein
-37-

(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
22. The process according to claim 12 wherein
(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
23. The process according to claim 15 wherein
(1) an additional heat and mass transfer means is included
inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
-38-

(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
24. The process according to claim 17 wherein
(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
25. An apparatus for the separation of a gas stream containing methane, C2
components, C3 components, and heavier hydrocarbon components into a volatile
residue gas
fraction and a relatively less volatile fraction containing a major portion of
said C3 components
and heavier hydrocarbon components comprising
(1) first heat exchange means housed in a single equipment item
processing assembly to cool said gas stream;
(2) expansion means connected to said first heat exchange means to
receive said cooled gas stream and expand it to lower pressure;
-39-

(3) absorbing means housed in said processing assembly and
connected to said expansion means to receive said expanded cooled gas stream
as a bottom feed
thereto;
(4) first liquid collecting means housed in said processing assembly
and connected to said absorbing means to receive a first distillation liquid
stream from a lower
region of said absorbing means;
(5) mass transfer means housed in said processing assembly and
connected to said first liquid collecting means to receive said first
distillation liquid stream as a
top feed thereto;
(6) first vapor collecting means housed in said processing assembly
and connected to said mass transfer means to receive a first distillation
vapor stream from an
upper region of said mass transfer means;
(7) second heat exchange means housed in said processing assembly
and connected to said first vapor collecting means to receive said first
distillation vapor stream
and cool it sufficiently to condense at least a part of it, thereby forming a
condensed stream and a
residual vapor stream containing any uncondensed vapor remaining after said
first distillation
vapor stream is cooled;
(8) said absorbing means being further connected to said second heat
exchange means to receive at least a portion of said condensed stream as a top
feed thereto;
(9) second vapor collecting means housed in said processing assembly
and connected to said absorbing means to receive a second distillation vapor
stream from an
upper region of said absorbing means;
-40-

(10) said second heat exchange means being further connected to said
second vapor collecting means to receive said second distillation vapor stream
and heat it,
thereby to supply at least a portion of the cooling of step (7);
(11) combining means connected to said second heat exchange means
to receive said heated second distillation vapor stream and any said residual
vapor stream and
form a combined vapor stream;
(12) said first heat exchange means being further connected to said
combining means to receive said combined vapor stream and heat it, thereby to
supply at least a
portion of the cooling of step (1), and thereafter discharging said heated
combined vapor stream
from said processing assembly as said volatile residue gas fraction;
(13) second liquid collecting means housed in said processing assembly
and connected to said mass transfer means to receive a second distillation
liquid stream from a
lower region of said mass transfer means;
(14) heat and mass transfer means housed in said processing assembly
and connected to said second liquid collecting means to receive said second
distillation liquid
stream and heat it, thereby to simultaneously strip the more volatile
components from said
second distillation liquid stream, and thereafter discharging said heated and
stripped second
distillation liquid stream from said processing assembly as said relatively
less volatile fraction;
and
(15) control means adapted to regulate the quantities and temperatures
of said feed streams to said absorbing means to maintain the temperature of
said upper region of
said absorbing means at a temperature whereby the major portions of the
components in said
relatively less volatile fraction are recovered.
-41-

26. The apparatus according to claim 25 wherein
(a) said first heat exchange means is housed in the processing
assembly to cool said gas stream sufficiently to partially condense it;
(b) separating means is connected to said first heat exchange means to
receive said partially condensed gas stream and separate it into a vapor
stream and at least one
liquid stream;
(c) said expansion means is connected to said separating means to
receive said vapor stream and expand it to lower pressure whereby it is
further cooled;
(d) said absorbing means is housed in said processing assembly and
connected to said expansion means to receive said expanded cooled vapor stream
as a bottom
feed thereto;
(e) further expansion means is connected to said separating means to
receive said at least one liquid stream and expand it to said lower pressure;
and
(f) said first heat exchange means is further connected to
said further
expansion means to receive said expanded at least one liquid stream and heat
it, thereby to
supply at least a portion of the cooling of step (a), said first heat exchange
means is further
connected to said mass transfer means to supply said heated expanded at least
one liquid stream
as a bottom feed thereto.
27. The apparatus according to claim 25 wherein
(a) further heat exchange means is connected to said first liquid
collecting means to receive said first distillation liquid stream and heat it;
(b) said mass transfer means is connected to said further heat exchange
means to receive said heated first distillation liquid stream as a top feed
thereto; and
-42-

(c) said further heat exchange means is further connected
to said first
vapor collecting means to receive said first distillation vapor stream and
cool it sufficiently to
condense at least a part of it, thereby to supply at least a portion of the
heating of step (a), and
thereby forming said condensed stream and said residual vapor stream.
28. The apparatus according to claim 27 wherein
(i) said first heat exchange means is housed in a processing assembly
to cool said gas stream sufficiently to partially condense it;
(ii) separating means is connected to said first heat exchange means to
receive said partially condensed gas stream and separate it into a vapor
stream and at least one
liquid stream;
(iii) said expansion means is connected to said separating means to
receive said vapor stream and expand it to lower pressure whereby it is
further cooled;
(iv) said absorbing means is housed in said processing assembly and
connected to said expansion means to receive said expanded cooled vapor stream
as a bottom
feed thereto;
(v) further expansion means is connected to said separating means to
receive said at least one liquid stream and expand it to said lower pressure;
and
(vi) said first heat exchange means is further connected to said further
expansion means to receive said expanded at least one liquid stream and heat
it, thereby to
supply at least a portion of the cooling of step (i), said first heat exchange
means is further
connected to said mass transfer means to supply said heated expanded at least
one liquid stream
as a bottom feed thereto.
-43-

29. The apparatus according to claim 25 wherein
(a) said first heat exchange means is housed in the processing
assembly to partially cool said gas stream;
(b) dividing means is connected to said first heat exchange means to
receive said partially cooled gas stream and divide it into first and second
portions;
(c) heat and mass transfer means housed in a separating means is
connected to said dividing means to receive said first portion and further
cool it, thereby to
simultaneously condense any less volatile components from said first portion;
(d) said first heat exchange means is further connected to said dividing
means to receive said second portion and further cool it;
(e) further combining means is connected to said heat and mass
transfer means housed in the separating means and said first heat exchange
means to receive said
further cooled first portion and said further cooled second portion and form a
cooled gas stream;
(f) expansion means is connected to said further combining
means to
receive said cooled gas stream and expand it to lower pressure;
(g) said heat and mass transfer means housed in the separating means
is further connected to said first liquid collecting means to receive said
first distillation liquid
stream and heat it, thereby to supply at least a portion of the cooling of
step (c);
(h) said mass transfer means is connected to said heat and mass
transfer means housed in the separating means to receive said heated first
distillation liquid
stream as a top feed thereto; and
(i) said first heat exchange means is further connected to said second
combining means to receive said combined vapor stream and heat it, thereby to
supply at least a
-44-

portion of the cooling of steps (a) and (d), and thereafter discharging said
heated combined vapor
stream from said processing assembly as said volatile residue gas fraction.
30. The apparatus according to claim 29 wherein
(a) said separating means is further connected to said first heat
exchange means to receive said further cooled second portion so that any
liquids condensed as
said first portion is further cooled and as said second portion is further
cooled are combined to
form at least one liquid stream, with the remainder of said further cooled
first portion and said
further cooled second portion forming a vapor stream;
(b) said expansion means is connected to said separating means to
receive said vapor stream and expand it to lower pressure whereby it is
further cooled;
(c) said absorbing means is connected to said expansion means to
receive said expanded cooled vapor stream as a bottom feed thereto;
(d) further expansion means is connected to said separating means to
receive said at least one liquid stream and expand it to said lower pressure;
and
(e) said first heat exchange means is further connected to said further
expansion means to receive said expanded at least one liquid stream and heat
it, thereby to
supply at least a portion of the cooling of step (1), said first heat exchange
means is further
connected to said mass transfer means to supply said heated expanded at least
one liquid stream
as a bottom feed thereto.
31. The apparatus according to claim 29 wherein
(i) third heat exchange means is connected to said
dividing means to
receive said first portion and further cool it;
-45-

(ii) said further combining means is connected to said third heat
exchange means and said first heat exchange means to receive said further
cooled first portion
and said further cooled second portion and form a cooled gas stream;
(iii) said third heat exchange means being further connected to said first
liquid collecting means to receive said first distillation liquid stream and
heat it, thereby to
supply at least a portion of the cooling of step (i); and
(iv) said mass transfer means housed is connected to said third heat
exchange means to receive said heated first distillation liquid stream as a
top feed thereto.
32. The apparatus according to claim 31 wherein
(a) said further combining means is connected to said third heat
exchange means and said first heat exchange means to receive said further
cooled first portion
and said further cooled second portion and form a partially condensed gas
stream;
(b) separating means is connected to said first combining means to
receive said partially condensed gas stream and separate it into a vapor
stream and at least one
liquid stream;
(c) said expansion means is connected to said separating means to
receive said vapor stream and expand it to lower pressure whereby it is
further cooled;
(d) absorbing means is housed in said processing assembly and
connected to said expansion means to receive said expanded cooled vapor stream
as a bottom
feed thereto;
(e) further expansion means is connected to said separating means to
receive said at least one liquid stream and expand it to said lower pressure;
and
-46-

(f) said first heat exchange means is further connected to
said further
expansion means to receive said expanded at least one liquid stream and heat
it, thereby to
supply at least a portion of the cooling of step (1), said first heat exchange
means is further
connected to said mass transfer means to supply said heated expanded at least
one liquid stream
as a bottom feed thereto.
33. The apparatus according to claim 27 wherein said second heat exchange
means is housed in said processing assembly.
34. The apparatus according to claim 28 wherein said second heat exchange
means is housed in said processing assembly.
35. The apparatus according to claim 26 wherein said separating means is
housed in said processing assembly.
36. The apparatus according to claim 28 or 34 wherein said separating means

is housed in said processing assembly.
37. The apparatus according to claim 29 or 30 wherein said separating means

is housed in said processing assembly.
38. The apparatus according to claim 32 wherein said separating means is
housed in said processing assembly.
39. The apparatus according to claim 27 or 33 wherein

-47-

(1) said mass transfer means is adapted to be connected to said second
heat exchange means to receive said heated first distillation liquid stream at
an intermediate feed
position;
(2) a dividing means is connected to said second heat exchange means
to receive said condensed stream and divide it into at least first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said dividing
means to receive said first reflux stream as said top feed thereto; and
(4) said mass transfer means is adapted to be connected to said
dividing means to receive said second reflux stream as said top feed thereto.
40. The apparatus according to claim 31 wherein
(1) said mass transfer means is adapted to be connected to said second
heat exchange means to receive said heated first distillation liquid stream at
an intermediate feed
position;
(2) an additional dividing means is connected to said third heat
exchange means to receive said condensed stream and divide it into at least
first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said additional
dividing means to receive said first reflux stream as said top feed thereto;
and
(4) said mass transfer means is adapted to be connected to said
additional dividing means to receive said second reflux stream as said top
feed thereto.
41. The apparatus according to claim 28 or 34 wherein

-48-

(1) said mass transfer means is adapted to be connected to said second
heat exchange means to receive said heated first distillation liquid stream at
an intermediate feed
position;
(2) a dividing means is connected to said second heat exchange means
to receive said condensed stream and divide it into at least first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said dividing
means to receive said first reflux stream as said top feed thereto; and
(4) said mass transfer means is adapted to be connected to said
dividing means to receive said second reflux stream as said top feed thereto.
42. The apparatus according to claim 29 or 30 wherein
(1) said mass transfer means is adapted to be connected to said first
heat and mass transfer means to receive said heated first distillation liquid
stream at an
intermediate feed position;
(2) an additional dividing means is connected to said second heat
exchange means to receive said condensed stream and divide it into at least
first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said additional
dividing means to receive said first reflux stream as said top feed thereto;
and
(4) said mass transfer means is adapted to be connected to said
additional dividing means to receive said second reflux stream as said top
feed thereto.
43. The apparatus according to claim 32 or 38 wherein

-49-

(1) said mass transfer means is adapted to be connected to said first
heat and mass transfer means to receive said heated first distillation liquid
stream at an
intermediate feed position;
(2) an additional dividing means is connected to said second heat
exchange means to receive said condensed stream and divide it into at least
first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said additional
dividing means to receive said first reflux stream as said top feed thereto;
and
(4) said mass transfer means is adapted to be connected to said
additional dividing means to receive said second reflux stream as said top
feed thereto.
44. The apparatus according to claim 36 wherein
(1) said mass transfer means is adapted to be connected to said second
heat exchange means to receive said heated first distillation liquid stream at
an intermediate feed
position;
(2) a dividing means is connected to said second heat exchange means
to receive said condensed stream and divide it into at least first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said dividing
means to receive said first reflux stream as said top feed thereto; and
(4) said mass transfer means is adapted to be connected to said
dividing means to receive said second reflux stream as said top feed thereto.
45. The apparatus according to claim 37 wherein

-50-

(1) said mass transfer means is adapted to be connected to said first
heat and mass transfer means to receive said heated first distillation liquid
stream at an
intermediate feed position;
(2) an additional dividing means is connected to said second heat
exchange means to receive said condensed stream and divide it into at least
first and second
reflux streams;
(3) said absorbing means is adapted to be connected to said additional
dividing means to receive said first reflux stream as said top feed thereto;
and
(4) said mass transfer means is adapted to be connected to said
additional dividing means to receive said second reflux stream as said top
feed thereto.
46. The apparatus according to claim 25 wherein
(1) a gas collecting means is housed in said processing assembly;
(2) an additional heat and mass transfer means is included inside said
gas collecting means, said additional heat and mass transfer means including
one or more passes
for an external refrigeration medium;
(3) said gas collecting means is connected to said first heat exchange
means to receive said cooled gas stream and direct it to said additional heat
and mass transfer
means to be further cooled by said external refrigeration medium; and
(4) said expansion means is adapted to be connected to said gas
collecting means to receive said further cooled gas stream and expand it to
said lower pressure,
said expansion means being further connected to said absorbing means to supply
said expanded
further cooled gas stream as said bottom feed thereto.

-51-

47. The apparatus according to claim 31 or 40 wherein
(1) a gas collecting means is housed in said processing assembly;
(2) an additional heat and mass transfer means is included inside said
gas collecting means, said additional heat and mass transfer means including
one or more passes
for an external refrigeration medium;
(3) said gas collecting means is connected to said first combining
means to receive said cooled gas stream and direct it to said additional heat
and mass transfer
means to be further cooled by said external refrigeration medium; and
(4) said expansion means is adapted to be connected to said gas
collecting means to receive said further cooled gas stream and expand it to
said lower pressure,
said expansion means being further connected to said absorbing means to supply
said expanded
further cooled gas stream as said bottom feed thereto.
48. The apparatus according to claim 39 wherein
(1) a gas collecting means is housed in said processing assembly;
(2) an additional heat and mass transfer means is included inside said
gas collecting means, said additional heat and mass transfer means including
one or more passes
for an external refrigeration medium;
(3) said gas collecting means is connected to said first combining
means to receive said cooled gas stream and direct it to said additional heat
and mass transfer
means to be further cooled by said external refrigeration medium; and
(4) said expansion means is adapted to be connected to said gas
collecting means to receive said further cooled gas stream and expand it to
said lower pressure,

-52-

said expansion means being further connected to said absorbing means to supply
said expanded
further cooled gas stream as said bottom feed thereto.
49. The apparatus according to claim 26, 28, 32, 34, 35, or 38 wherein
(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
50. The apparatus according to claim 36 wherein
(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
51. The apparatus according to claim 41 wherein

-53-

(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
52. The apparatus according to claim 43 wherein
(1) an additional heat and mass transfer means is included inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;
(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.
53. The apparatus according to claim 44 wherein
(1) an additional heat and mass transfer means is included
inside said
separating means, said additional heat and mass transfer means including one
or more passes for
an external refrigeration medium;

-54-

(2) said vapor stream is directed to said additional heat and mass
transfer means to be cooled by said external refrigeration medium to form
additional condensate;
and
(3) said condensate becomes a part of said at least one liquid stream
separated therein.

-55-

Note: Descriptions are shown in the official language in which they were submitted.


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
HYDROCARBON GAS PROCESSING

SPECIFICATION
BACKGROUND OF THE INVENTION

[0001] This invention relates to a process and apparatus for the separation of
a
gas containing hydrocarbons. The applicants claim the benefits under Title 35,
United
States Code, Section 119(e) of prior U.S. Provisional Application Number
61/186,361
which was filed on June 11, 2009. The applicants also claim the benefits under
Title
35, United States Code, Section 120 as a continuation-in-part of U.S. Patent

Application No. 12/717,394 which was filed on March 4, 2010, and as a
continuation-in-part of U.S. Patent Application No. 12/689,616 which was filed
on
-1-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
January 19, 2010, and as a continuation-in-part of U.S. Patent Application No.
12/372,604 which was filed on February 17, 2009. Assignees S.M.E. Products LP
and Ortloff Engineers, Ltd. were parties to a joint research agreement that
was in
effect before the invention of this application was made.

[00021 Propylene, propane, and/or heavier hydrocarbons can be recovered
from a variety of gases, such as natural gas, refinery gas, and synthetic gas
streams
obtained from other hydrocarbon materials such as coal, crude oil, naphtha,
oil shale,
tar sands, and lignite. Natural gas usually has a major proportion of methane
and
ethane, i.e., methane and ethane together comprise at least 50 mole percent of
the gas.
The gas also contains relatively lesser amounts of heavier hydrocarbons such
as
propane, butanes, pentanes, and the like, as well as hydrogen, nitrogen,
carbon
dioxide, and other gases.

[00031 The present invention is generally concerned with the recovery of
propylene, propane, and heavier hydrocarbons from such gas streams. A typical
analysis of a gas stream to be processed in accordance with this invention
would be,
in approximate mole percent, 88.4% methane, 6.2% ethane and other C2
components,
2.6% propane and other C3 components, 0.3% iso-butane, 0.6% normal butane, and
0.8% pentanes plus, with the balance made up of nitrogen and carbon dioxide.
Sulfur
containing gases are also sometimes present.

[00041 The historically cyclic fluctuations in the prices of both natural gas
and
its natural gas liquid (NGL) constituents have at times reduced the
incremental value
of propane, propylene, and heavier components as liquid products. This has
resulted
in a demand for processes that can provide more efficient recoveries of these
products
and for processes that can provide efficient recoveries with lower capital
investment.
Available processes for separating these materials include those based upon
cooling
-2-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
and refrigeration of gas, oil absorption, and refrigerated oil absorption.
Additionally,
cryogenic processes have become popular because of the availability of
economical
equipment that produces power while simultaneously expanding and extracting
heat
from the gas being processed. Depending upon the pressure of the gas source,
the
richness (ethane, ethylene, and heavier hydrocarbons content) of the gas, and
the
desired end products, each of these processes or a combination thereof may be
employed.

[0005] The cryogenic expansion process is now generally preferred for natural
gas liquids recovery because it provides maximum simplicity with ease of
startup,
operating flexibility, good efficiency, safety, and good reliability. U.S.
Patent Nos.
3,292,380; 4,061,481; 4,140,504; 4,157,904; 4,171,964; 4,185,978; 4,251,249;
4,278,457; 4,519,824; 4,617,039; 4,687,499; 4,689,063; 4,690,702; 4,854,955;
4,869,740; 4,889,545; 5,275,005; 5,555,748; 5,566,554; 5,568,737; 5,771,712;
5,799,507; 5,881,569; 5,890,378; 5,983,664; 6,182,469; 6,578,379; 6,712,880;
6,915,662; 7,191,617; 7,219,513; reissue U.S. Patent No. 33,408; and co-
pending
application nos. 11/430,412; 11/839,693; 11/971,491; and 12/206,230 describe
relevant processes (although the description of the present invention in some
cases is
based on different processing conditions than those described in the cited
U.S.
Patents).

[0006] In a typical cryogenic expansion recovery process, a feed gas stream
under pressure is cooled by heat exchange with other streams of the process
and/or
external sources of refrigeration such as a propane compression-refrigeration
system.
As the gas is cooled, liquids may be condensed and collected in one or more

separators as high-pressure liquids containing some of the desired C3+
components.
Depending on the richness of the gas and the amount of liquids formed, the

-3-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
high-pressure liquids may be expanded to a lower pressure and fractionated.
The
vaporization occurring during expansion of the liquids results in further
cooling of the
stream. Under some conditions, pre-cooling the high pressure liquids prior to
the
expansion may be desirable in order to further lower the temperature resulting
from
the expansion. The expanded stream, comprising a mixture of liquid and vapor,
is
fractionated in a distillation (deethanizer) column. In the column, the
expansion
cooled stream(s) is (are) distilled to separate residual methane, C2
components,
nitrogen, and other volatile gases as overhead vapor from the desired C3
components
and heavier hydrocarbon components as bottom liquid product.

[0007] If the feed gas is not totally condensed (typically it is not), the
vapor
remaining from the partial condensation can be passed through a work expansion
machine or engine, or an expansion valve, to a lower pressure at which
additional
liquids are condensed as a result of further cooling of the stream. The
expanded
stream then enters an absorbing section in the column and is contacted with
cold
liquids to absorb the C3 components and heavier components from the vapor
portion
of the expanded stream. The liquids from the absorbing section are then
directed to
the deethanizing section of the column.

[0008] A distillation vapor stream is withdrawn from the upper region of the
deethanizing section and is cooled by heat exchange relation with the overhead
vapor
stream from the absorbing section, condensing at least a portion of the
distillation
vapor stream. The condensed liquid is separated from the cooled distillation
vapor
stream to produce a cold liquid reflux stream that is directed to the upper
region of the
absorbing section, where the cold liquids can contact the vapor portion of the
expanded stream as described earlier. The vapor portion (if any) of the cooled

-4-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
distillation vapor stream and the overhead vapor from the absorbing section
combine
to form the residual methane and C2 component product gas.

[0009] The separation that takes place in this process (producing a residue
gas
leaving the process which contains substantially all of the methane and C2
components in the feed gas with essentially none of the C3 components and
heavier
hydrocarbon components, and a bottoms fraction leaving the deethanizer which
contains substantially all of the C3 components and heavier hydrocarbon
components
with essentially no methane, C2 components or more volatile components)
consumes
energy for feed gas cooling, for reboiling the deethanizing section, for
refluxing the
absorbing section, and/or for re-compressing the residue gas.

[0010] The present invention employs a novel means of performing the
various steps described above more efficiently and using fewer pieces of
equipment.
This is accomplished by combining what heretofore have been individual
equipment
items into a common housing, thereby reducing the plot space required for the

processing plant and reducing the capital cost of the facility. Surprisingly,
applicants
have found that the more compact arrangement also significantly reduces the
power
consumption required to achieve a given recovery level, thereby increasing the

process efficiency and reducing the operating cost of the facility. In
addition, the
more compact arrangement also eliminates much of the piping used to
interconnect
the individual equipment items in traditional plant designs, further reducing
capital
cost and also eliminating the associated flanged piping connections. Since
piping
flanges are a potential leak source for hydrocarbons (which are volatile
organic
compounds, VOCs, that contribute to greenhouse gases and may also be
precursors to
atmospheric ozone formation), eliminating these flanges reduces the potential
for
atmospheric emissions that can damage the environment.

-5-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[0011] In accordance with the present invention, it has been found that C3
recoveries in excess of 99.6% can be obtained while providing essentially
complete
rejection of C2 components to the residue gas stream. In addition, the present
invention makes possible essentially 100% separation of C2 components and
lighter
components from the C3 components and heavier components at lower energy
requirements compared to the prior art while maintaining the same recovery
level.

The present invention, although applicable at lower pressures and warmer
temperatures, is particularly advantageous when processing feed gases in the
range of
400 to 1500 psia [2,758 to 10,342 kPa(a)] or higher under conditions requiring
NGL
recovery column overhead temperatures of -50 F [-46 C] or colder.

[0012] For a better understanding of the present invention, reference is made
to the following examples and drawings. Referring to the drawings:

[0013] FIG. 1 is a flow diagram of a prior art natural gas processing plant in
accordance with United States Patent No. 5,799,507;

[0014] FIG. 2 is a flow diagram of a natural gas processing plant in
accordance with the present invention; and

[0015] FIGS. 3 through 13 are flow diagrams illustrating alternative means of
application of the present invention to a natural gas stream.

[0016] In the following explanation of the above figures, tables are provided
summarizing flow rates calculated for representative process conditions. In
the tables
appearing herein, the values for flow rates (in moles per hour) have been
rounded to
the nearest whole number for convenience. The total stream rates shown in the
tables
include all non-hydrocarbon components and hence are generally larger than the
sum
of the stream flow rates for the hydrocarbon components. Temperatures
indicated are
approximate values rounded to the nearest degree. It should also be noted that
the

-6-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
process design calculations performed for the purpose of comparing the
processes
depicted in the figures are based on the assumption of no heat leak from (or
to) the
surroundings to (or from) the process. The quality of commercially available

insulating materials makes this a very reasonable assumption and one that is
typically
made by those skilled in the art.

[0017] For convenience, process parameters are reported in both the
traditional British units and in the units of the Systeme International
d'Unites (SI).
The molar flow rates given in the tables may be interpreted as either pound
moles per
hour or kilogram moles per hour. The energy consumptions reported as
horsepower
(HP) and/or thousand British Thermal Units per hour (MBTU/Hr) correspond to
the
stated molar flow rates in pound moles per hour. The energy consumptions
reported
as kilowatts (kW) correspond to the stated molar flow rates in kilogram moles
per
hour.

DESCRIPTION OF THE PRIOR ART

[0018] FIG. 1 is a process flow diagram showing the design of a processing
plant to recover C3+ components from natural gas using prior art according to
U.S.
Pat. No. 5,799,507. In this simulation of the process, inlet gas enters the
plant at
110 F [43 C] and 885 psia [6,100 kPa(a)] as stream 31. If the inlet gas
contains a
concentration of sulfur compounds which would prevent the product streams from
meeting specifications, the sulfur compounds are removed by appropriate

pretreatment of the feed gas (not illustrated). In addition, the feed stream
is usually
dehydrated to prevent hydrate (ice) formation under cryogenic conditions.
Solid
desiccant has typically been used for this purpose.

-7-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[0019] The feed stream 31 is cooled in heat exchanger 10 by heat exchange
with cool residue gas (stream 44), flash expanded separator liquids (stream
35a), and
distillation liquids at -105 F [-76 C] (stream 43). The cooled stream 31a
enters
separator 11 at -34 F [-36 C] and 875 psia [6,031 kPa(a)] where the vapor
(stream 34)
is separated from the condensed liquid (stream 35). The separator liquid
(stream 35)
is expanded to slightly above the operating pressure (approximately 375 psia

[2,583 kPa(a)]) of fractionation tower 15 by expansion valve 12, cooling
stream 35a
to -65 F [-54 C]. Stream 35a enters heat exchanger 10 to supply cooling to the
feed
gas as described previously, heating stream 35b to 105 F [41 C] before it is
supplied
to fractionation tower 15 at a lower mid-column feed point.

[00201 The vapor (stream 34) from separator 11 enters a work expansion
machine 13 in which mechanical energy is extracted from this portion of the
high
pressure feed. The machine 13 expands the vapor substantially isentropically
to the
operating pressure of fractionation tower 15, with the work expansion cooling
the
expanded stream 34a to a temperature of approximately -100 F [-74 C]. The
typical
commercially available expanders are capable of recovering on the order of 80-
85%
of the work theoretically available in an ideal isentropic expansion. The work
recovered is often used to drive a centrifugal compressor (such as item 14)
that can be
used to re-compress the heated residue gas (stream 44a), for example. The
partially
condensed expanded stream 34a is thereafter supplied as feed to fractionation
tower
15 at an upper mid-column feed point.

[00211 The deethanizer in tower 15 is a conventional distillation column
containing a plurality of vertically spaced trays, one or more packed beds, or
some
combination of trays and packing. The deethanizer tower consists of two
sections: an
upper absorbing (rectification) section 15a that contains the trays and/or
packing to

-8-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
provide the necessary contact between the vapor portion of the expanded stream
34a
rising upward and cold liquid falling downward to condense and absorb the C3
components and heavier components; and a lower stripping section 15b that
contains
the trays and/or packing to provide the necessary contact between the liquids
falling
downward and the vapors rising upward. The deethanizing section 15b also
includes
at least one reboiler (such as reboiler 16) which heats and vaporizes a
portion of the
liquids flowing down the column to provide the stripping vapors which flow up
the
column to strip the liquid product, stream 37, of methane, C2 components, and
lighter
components. Stream 34a enters deethanizer 15 at a mid-column feed position
located
in the lower region of absorbing section 15a of deethanizer 15. The liquid
portion of
expanded stream 34a commingles with liquids falling downward from absorbing
section 15a and the combined liquid continues downward into stripping section
15b
of deethanizer 15. The vapor portion of expanded stream 34a rises upward
through
absorbing section 15a and is contacted with cold liquid falling downward to
condense
and absorb the C3 components and heavier components.

[0022] A portion of the distillation vapor (stream 38) is withdrawn from the
upper region of stripping section 15b. This stream is then cooled and
partially
condensed (stream 38a) in exchanger 17 by heat exchange with cold deethanizer
overhead stream 36 which exits the top of deethanizer 15 at -109 F [-79 C].
The cold
deethanizer overhead stream is warmed to approximately -33 F [-66 C] (stream
36a)
as it cools stream 38 from -30 F [-35 C] to about -103 F [-75 C] (stream 38a).

[0023] The operating pressure in reflux separator 18 is maintained slightly
below the operating pressure of deethanizer 15. This pressure difference
provides the
driving force that allows distillation vapor stream 38 to flow through heat
exchanger
17 and thence into the reflux separator 18 wherein the condensed liquid
(stream 40) is
-9-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
separated from the uncondensed vapor (stream 39). The uncondensed vapor stream
39 combines with the warmed deethanizer overhead stream 36a from exchanger 17
to
form cool residue gas stream 44 at -37 F [-38 C].

[0024] The liquid stream 40 from reflux separator 18 is pumped by pump 19
to a pressure slightly above the operating pressure of deethanizer 15. The
resulting
stream 40a is then divided into two portions. The first portion (stream 41) is
supplied
as cold top column feed (reflux) to the upper region of absorbing section 15a
of
deethanizer 15. This cold liquid causes an absorption cooling effect to occur
inside
the absorbing (rectification) section 15a of deethanizer 15, wherein the
saturation of
the vapors rising upward through the tower by vaporization of liquid methane
and
ethane contained in stream 41 provides refrigeration to the section. Note
that, as a
result, both the vapor leaving the upper region (overhead stream 36) and the
liquids
leaving the lower region (distillation liquid stream 43) of absorbing section
15a are
colder than the either of the feed streams (streams 41 and stream 34a) to
absorbing
section 15a. This absorption cooling effect allows the tower overhead (stream
36) to
provide the cooling needed in heat exchanger 17 to partially condense the
distillation
vapor stream (stream 38) without operating stripping section 15b at a pressure
significantly higher than that of absorbing section 15a. This absorption
cooling effect
also facilitates reflux stream 41 condensing and absorbing the C3 components
and
heavier components in the distillation vapor flowing upward through absorbing
section 15a. The second portion (stream 42) of pumped stream 40a is supplied
to the
upper region of stripping section 15b of deethanizer 15 where the cold liquid
acts as
reflux to absorb and condense the C3 components and heavier components flowing
upward from below so that distillation vapor stream 38 contains minimal
quantities of
these components.

-10-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[00251 A distillation liquid stream 43 from deethanizer 15 is withdrawn from
the lower region of absorbing section 15a and is routed to heat exchanger 10
where it
is heated as it provides cooling of the incoming feed gas as described
earlier.

Typically the flow of this liquid from the deethanizer is via thermosiphon
circulation,
but a pump could be used. The liquid stream is heated to -4 F [-20 C],
partially
vaporizing stream 43a before it is returned as a mid-column feed to
deethanizer 15, in
the middle region of stripping section 15b.

[00261 In stripping section 15b of deethanizer 15, the feed streams are
stripped of their methane and C2 components. The resulting liquid product
stream 37
exits the bottom of the tower at 201 F [94 C] based on a typical specification
of an
ethane to propane ratio of 0.048:1 on a molar basis in the bottom product. The
cool
residue gas (stream 44) passes countercurrently to the incoming feed gas in
heat
exchanger 10 where it is heated to 98 F [37 C] (stream 44a). The residue gas
is then
re-compressed in two stages. The first stage is compressor 14 driven by
expansion
machine 13. The second stage is compressor 20 driven by a supplemental power
source which compresses the residue gas (stream 44c) to sales line pressure.
After
cooling to 120 F [49 C] in discharge cooler 21, residue gas stream 44d flows
to the
sales gas pipeline at 915 psia [6,307 kPa(a)], sufficient to meet line
requirements
(usually on the order of the inlet pressure).

[0027] A summary of stream flow rates and energy consumption for the
process illustrated in FIG. 1 is set forth in the following table:

-11-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
Table I

(FIG. 1)

Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]

Stream Methane Ethane Propane Butanes+ Total
31 19,419 1,355 565 387 21,961
34 18,742 1,149 360 98 20,573
35 677 206 205 289 1,388
36 18,400 1,242 3 0 19,869
38 2,759 1,758 15 0 4,602
39 1,019 86 0 0 1,116
40 1,740 1,672 15 0 3,486
41 1,044 1,003 9 0 2,092
42 696 669 6 0 1,394
43 1,388 911 365 98 2,796
44 19,419 1,328 3 0 20,985
37 0 27 562 387 976
-12-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
Recoveries *

Propane 99.56%
Butanes+ 100.00%
Power

Residue Gas Compression 9,868 HP [ 16,223 kW]
Reflux Pump 19 HP [ 31 kW]
Totals 9,887 HP [ 16,254 kW]
* (Based on un-rounded flow rates)

DESCRIPTION OF THE INVENTION

[0028] FIG. 2 illustrates a flow diagram of a process in accordance with the
present invention. The feed gas composition and conditions considered in the
process
presented in FIG. 2 are the same as those in FIG. 1. Accordingly, the FIG. 2
process
can be compared with that of the FIG. 1 process to illustrate the advantages
of the
present invention.

[0029] In the simulation of the FIG. 2 process, inlet gas enters the plant as
stream 31 and enters a heat exchange means in feed cooling section 115a inside
processing assembly 115. This heat exchange means may be comprised of a fin
and
tube type heat exchanger, a plate type heat exchanger, a brazed aluminum type
heat
exchanger, or other type of heat transfer device, including multi-pass and/or
multi-service heat exchangers. The heat exchange means is configured to
provide
heat exchange between stream 31 flowing through one pass of the heat exchange
means and flash expanded separator liquids (stream 35a) and a residue gas
stream

-13-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
from condensing section 115b inside processing assembly 115. Stream 31 is
cooled
while heating the flash expanded separator liquids and the residue gas stream.
A first
portion (stream 32) of stream 31 is withdrawn from the heat exchange means
after
stream 31 has been partially cooled to 25 F [-4 C], while the remaining second
portion (stream 33) is further cooled so that it leaves the heat exchange
means at
-20 F [-29 C].

[0030] Separator section 115e has an internal head or other means to divide it
from deethanizing section 115d, so that the two sections inside processing
assembly
115 can operate at different pressures. The first portion (stream 32) of
stream 31
enters the lower region of separator section 115e at 875 psia [6,031 kPa(a)]
where any
condensed liquid is separated from the vapor before the vapor is directed into
a heat
and mass transfer means inside separator section 115e. This heat and mass
transfer
means may also be comprised of a fin and tube type heat exchanger, a plate
type heat
exchanger, a brazed aluminum type heat exchanger, or other type of heat
transfer
device, including multi-pass and/or multi-service heat exchangers. The heat
and mass
transfer means is configured to provide heat exchange between the vapor
portion of
stream 32 flowing upward through one pass of the heat and mass transfer means
and
distillation liquid stream 43 from absorbing section 115c inside processing
assembly
115 flowing downward, so that the vapor is cooled while heating the
distillation liquid
stream. As the vapor stream is cooled, a portion of it may be condensed and
fall
downward while the remaining vapor continues flowing upward through the heat
and
mass transfer means. The heat and mass transfer means provides continuous
contact
between the condensed liquid and the vapor so that it also functions to
provide mass
transfer between the vapor and liquid phases to provide partial rectification
of the
vapor.

-14-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[00311 The second portion (stream 33) of stream 31 enters separator section
115e inside processing assembly 115 above the heat and mass transfer means.
Any
condensed liquid is separated from the vapor and commingles with any liquid
that is
condensed from the vapor portion of stream 32 flowing up through the heat and
mass
transfer means. The vapor portion of stream 33 combines with the vapor leaving
the
heat and mass transfer means to form stream 34, which exits separator section
115e at
-31 F [-35 C]. The liquid portions (if any) of streams 32 and 33 and any
liquid
condensed from the vapor portion of stream 32 in the heat and mass transfer
means
combine to form stream 35, which exits separator section 115e at -15 F [-26
C]. It is
expanded to slightly above the operating pressure (approximately 383 psia

[2,639 kPa(a)]) of deethanizing section 115d inside processing assembly 115 by
expansion valve 12, cooling stream 35a to -42 F [-41 C]. Stream 35a enters the
heat
exchange means in feed cooling section 115a to supply cooling to the feed gas
as
described previously, heating stream 35b to 103 F [39 C] before it is supplied
to
deethanizing section 115d inside processing assembly 115 at a lower mid-column
feed point.

[00321 The vapor (stream 34) from separator section 115e enters a work
expansion machine 13 in which mechanical energy is extracted from this portion
of
the high pressure feed. The machine 13 expands the vapor substantially
isentropically
to the operating pressure (approximately 380 psia [2,618 kPa(a)]) of absorbing
section
115c, with the work expansion cooling the expanded stream 34a to a temperature
of
approximately -98 F [-72 C]. The partially condensed expanded stream 34a is
thereafter supplied as feed to the lower region of absorbing section 115c
inside
processing assembly 115.

-15-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[0033] Absorbing section 115c contains an absorbing means consisting of a
plurality of vertically spaced trays, one or more packed beds, or some
combination of
trays and packing. The trays and/or packing in absorbing section 115c provide
the
necessary contact between the vapors rising upward and cold liquid falling
downward.
The vapor portion of expanded stream 34a rises upward through the absorbing
means
in absorbing section 115c to be contacted with the cold liquid falling
downward to
condense and absorb most of the C3 components and heavier components from
these
vapors. The liquid portion of expanded stream 34a commingles with liquids
falling
downward from the absorbing means in absorbing section 115c to form
distillation
liquid stream 43, which is withdraw from the lower region of absorbing section
115c
at -102 F [-74 C]. The distillation liquid is heated to -9 F [-23 C] as it
cools the
vapor portion of stream 32 in separator section 115e as described previously,
with the
heated distillation liquid stream 43a thereafter supplied to deethanizing
section 115d
inside processing assembly 115 at an upper mid-column feed point. Typically
the
flow of this liquid from absorbing section 115c through the heat and mass
transfer
means in separator section 115e to deethanizing section 115d is via
thermosiphon
circulation, but a pump could be used.

[0034] Absorbing section 115c has an internal head or other means to divide it
from deethanizing section 115d, so that the two sections inside processing
assembly
115 can operate with the pressure of deethanizing section 115d slightly higher
than
that of absorbing section 115c. This pressure difference provides the driving
force
that allows a first distillation vapor stream (stream 38) to be withdrawn from
the
upper region of deethanizing section 115d and directed to the heat exchange
means in
condensing section 115b inside processing assembly 115. This heat exchange
means
may likewise be comprised of a fin and tube type heat exchanger, a plate type
heat

-16-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
exchanger, a brazed aluminum type heat exchanger, or other type of heat
transfer
device, including multi-pass and/or multi-service heat exchangers. The heat
exchange
means is configured to provide heat exchange between first distillation vapor
stream
38 flowing through one pass of the heat exchange means and a second
distillation
vapor stream arising from absorbing section 115c inside processing assembly
115.
The second distillation vapor stream is heated while it cools and at least
partially
condenses stream 38, which thereafter exits the heat exchange means and is
separated
into its respective vapor and liquid phases. The vapor phase (if any) combines
with
the heated second distillation vapor stream exiting the heat exchange means to
form
the residue gas stream that provides cooling in feed cooling section 115a as
described
previously. The liquid phase is divided into two portions, streams 41 and 42.

[0035] The first portion (stream 41) is supplied as cold top column feed
(reflux) to the upper region of absorbing section 115c inside processing
assembly 115
by gravity flow. This cold liquid causes an absorption cooling effect to occur
inside
absorbing (rectification) section 115a, wherein the saturation of the vapors
rising
upward through the tower by vaporization of liquid methane and ethane
contained in
stream 41 provides refrigeration to the section. This absorption cooling
effect allows
the second distillation vapor stream to provide the cooling needed in the heat
exchange means in condensing section 115b to partially condense the first
distillation
vapor stream (stream 38) without operating deethanizing section 115d at a
pressure
significantly higher than that of absorbing section 115c. This absorption
cooling
effect also facilitates reflux stream 41 condensing and absorbing the C3
components
and heavier components in the distillation vapor flowing upward through
absorbing
section 115c. The second portion (stream 42) of the liquid phase separated in
condensing section 115b is supplied as cold top column feed (reflux) to the
upper

-17-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
region of deethanizing section 115d inside processing assembly 115 by gravity
flow,
so that the cold liquid acts as reflux to absorb and condense the C3
components and
heavier components flowing upward from below so that distillation vapor stream
38
contains minimal quantities of these components.

[0036] Deethanizing section 115d inside processing assembly 115 contains a
mass transfer means consisting of a plurality of vertically spaced trays, one
or more
packed beds, or some combination of trays and packing. The trays and/or
packing in
deethanizing section 115d provide the necessary contact between the vapors
rising
upward and cold liquid falling downward. Deethanizing section 115d also
includes a
heat and mass transfer means beneath the mass transfer means. This heat and
mass
transfer means may also be comprised of a fin and tube type heat exchanger, a
plate
type heat exchanger, a brazed aluminum type heat exchanger, or other type of
heat
transfer device, including multi-pass and/or multi-service heat exchangers.
The heat
and mass transfer means is configured to provide heat exchange between a
heating
medium flowing through one pass of the heat and mass transfer means and a
distillation liquid stream flowing downward from the mass transfer means in
deethanizing section 115d, so that the distillation liquid stream is heated.
As the
distillation liquid stream is heated, a portion of it is vaporized to form
stripping vapors
that rise upward as the remaining liquid continues flowing downward through
the heat
and mass transfer means. The heat and mass transfer means provides continuous
contact between the stripping vapors and the distillation liquid stream so
that it also
functions to provide mass transfer between the vapor and liquid phases,
stripping the
liquid product stream 37 of methane, C2 components, and lighter components.
The
resulting liquid product (stream 37) exits the lower region of deethanizing
section
115d and leaves processing assembly 115 at 203 F [95 C].

-18-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[0037] The second distillation vapor stream arising from absorbing section
115c is warmed in condensing section 115b as it provides cooling to stream 38
as
described previously. The warmed second distillation vapor stream combines
with
any vapor separated from the cooled first distillation vapor stream 38 as
described
previously. The resulting residue gas stream is heated in feed cooling section
115a as
it provides cooling to stream 31 as described previously, whereupon residue
gas
stream 44 leaves processing assembly 115 at 104 F [40 C]. The residue gas
stream is
then re-compressed in two stages, compressor 14 driven by expansion machine 13
and
compressor 20 driven by a supplemental power source. After cooling to 120 F

[49 C] in discharge cooler 21, residue gas stream 44c flows to the sales gas
pipeline at
915 psia [6,307 kPa(a)], sufficient to meet line requirements (usually on the
order of
the inlet pressure).

[0038] A summary of stream flow rates and energy consumption for the
process illustrated in FIG. 2 is set forth in the following table:

-19-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
Table II

(FIG. 2)

Stream Flow Summary - Lb. Moles/Hr [kg moles/Hr]

Stream Methane Ethane Propane Butanes+ Total
31 19,419 1,355 565 387 21,961
32 4,855 339 141 97 5,490
33 14,564 1,016 424 290 16,471
34 18,870 1,135 348 104 20,683
35 549 220 217 283 1,278
38 2,398 1,544 13 0 4,015
41 1,018 868 8 0 1,924
42 737 628 5 0 1,394
43 1,112 723 353 104 2,320
44 19,419 1,328 3 0 20,984
37 0 27 562 387 977
Recoveries *

Propane 99.63%
Butanes+ 100.00%
Power

Residue Gas Compression 9,363 HP [ 15,393 kW]
* (Based on un-rounded flow rates)

-20-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[00391 A comparison of Tables I and II shows that the present invention
maintains essentially the same recoveries as the prior art. However, further
comparison of Tables I and II shows that the product yields were achieved
using
significantly less power than the prior art. In terms of the recovery
efficiency

(defined by the quantity of propane recovered per unit of power), the present
invention represents more than a 5% improvement over the prior art of the FIG.
1
process.

[00401 The improvement in recovery efficiency provided by the present
invention over that of the prior art of the FIG. 1 process is primarily due to
three
factors. First, the compact arrangement of the heat exchange means in feed
cooling
section 115a and condensing section 115b in processing assembly 115 eliminates
the
pressure drop imposed by the interconnecting piping found in conventional
processing
plants. The result is that the residue gas flowing to compressor 14 is at
higher
pressure for the present invention compared to the prior art, so that the
residue gas
entering compressor 20 is at significantly higher pressure, thereby reducing
the power
required by the present invention to restore the residue gas to pipeline
pressure.

[00411 Second, using the heat and mass transfer means in deethanizing section
115d to simultaneously heat the distillation liquid leaving the mass transfer
means in
deethanizing section 115d while allowing the resulting vapors to contact the
liquid
and strip its volatile components is more efficient than using a conventional
distillation column with external reboilers. The volatile components are
stripped out
of the liquid continuously, reducing the concentration of the volatile
components in
the stripping vapors more quickly and thereby improving the stripping
efficiency for
the present invention.

-21-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[00421 Third, using the heat and mass transfer means in separator section 115e
to simultaneously cool the vapor portion of stream 32 while condensing the
heavier
hydrocarbon components from the vapor provides partial rectification of stream
34
before it is subsequently expanded and supplied as feed to absorbing section
115c. As
a result, less reflux flow (stream 41) is required to rectify the expanded
stream 34a to
remove the C3 components and heavier hydrocarbon components from it, as seen
by
comparing the flow rate of stream 41 in Tables I and II.

[00431 The present invention offers two other advantages over the prior art in
addition to the increase in processing efficiency. First, the compact
arrangement of
processing assembly 115 of the present invention replaces six separate
equipment
items in the prior art (heat exchangers 10 and 17, separator 11, reflux
separator 18,
reflux pump 19, and fractionation tower 15 in FIG. 1) with a single equipment
item
(processing assembly 115 in FIG. 2). This reduces the plot space requirements,
eliminates the interconnecting piping, and eliminates the power consumed by
the
reflux pump, reducing the capital cost and operating cost of a process plant
utilizing
the present invention over that of the prior art. Second, elimination of the
interconnecting piping means that a processing plant utilizing the present
invention
has far fewer flanged connections compared to the prior art, reducing the
number of
potential leak sources in the plant. Hydrocarbons are volatile organic
compounds
(VOCs), some of which are classified as greenhouse gases and some of which may
be
precursors to atmospheric ozone formation, which means the present invention
reduces the potential for atmospheric releases that can damage the
environment.

-22-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
Other Embodiments

[0044] As described earlier for the embodiment of the present invention
shown in FIG. 2, the first distillation vapor stream 38 is partially condensed
and the
resulting condensate used to absorb valuable C3 components and heavier
components
from the vapors leaving the work expansion machine. However, the present
invention
is not limited to this embodiment. It may be advantageous, for instance, to
treat only
a portion of the outlet vapor from the work expansion machine in this manner,
or to
use only a portion of the condensate as an absorbent, in cases where other
design
considerations indicate portions of the expansion machine outlet or the
condensate
should bypass absorbing section 115c of processing assembly 115. Feed gas
conditions, plant size, available equipment, or other factors may indicate
that
elimination of work expansion machine 13, or replacement with an alternate
expansion device (such as an expansion valve), is feasible, or that total
(rather than
partial) condensation of first distillation vapor stream 38 in condensing
section 115b
inside processing assembly 115 is possible or is preferred. It should also be
noted
that, depending on the composition of the feed gas stream, it may be
advantageous to
use external refrigeration to provide partial cooling of first distillation
vapor stream 38
in condensing section 115b.

[0045] In some circumstances, it may be advantageous to use an external
separator vessel to separate cooled first and second portions 32 and 33 or
cooled feed
stream 31a, rather than including separator section 115e in processing
assembly 115.
As shown in FIG. 8, a heat and mass transfer means in separator 11 can be used
to
separate cooled first and second portions 32 and 33 into vapor stream 34 and
liquid
stream 35. Likewise, as shown in FIGS. 9 through 13, separator 11 can be used
to
separate cooled feed stream 31a into vapor stream 34 and liquid stream 35.

-23-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
[00461 The use and distribution of the liquid stream 35 from separator section
115e or separator 11 and distillation liquid stream 43 from absorbing section
115c for
process heat exchange, the particular arrangement of heat exchangers for
cooling feed
gas (streams 31 and/or 32) and first distillation vapor stream 38, and the
choice of
process streams for specific heat exchange services must be evaluated for each
particular application. For instance, FIGS. 4 through 6 and 10 through 12
depict
using distillation liquid stream 43 to supply a portion of the cooling of
first distillation
vapor stream 38 in condensing section 115b (FIGS. 4, 5, 10, and 11) or heat
exchanger 10 (FIGS. 6 and 12). In such cases, a heat and mass transfer means
may
not be needed in separator section 115e (FIGS. 4 through 6) or separator 11
(FIGS. 10
through 12). In the embodiments shown in FIGS. 4 and 10, a pump 22 is used to
deliver distillation liquid stream 43 to the heat exchange means in condensing
section
115b. In the embodiments shown in FIGS. 5 and 11, condensing section 115b is
located below absorbing section 115c in processing assembly 115 so that flow
of
distillation liquid stream 43 is via thermosiphon circulation. In the
embodiments
shown in FIGS. 6 and 12, a heat exchanger 10 external to processing assembly
115 is
employed and feed cooling section 115a is located below absorbing section 115c
in
processing assembly 115 so that flow of distillation liquid stream 43 is via
thermosiphon circulation. (The embodiments shown in FIGS. 5, 6, 11, and 12 use
reflux pump 19 to supply reflux to locations above the point in processing
assembly
115 where the liquid phase condensed from stream 38 is collected.) Some
circumstances may favor using distillation liquid stream 43 to cool stream 32
in a heat
exchanger external to processing assembly 115, such as heat exchanger 10
depicted in
FIGS. 3 and 9. Still other circumstances may favor no heating of distillation
liquid
stream 43 at all, and instead using distillation liquid stream 43 as the
reflux to the

-24-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
upper region of deethanizing section 115d as shown in FIGS. 7 and 13. (For the
embodiment shown in FIG. 13, pump 22 may be needed because gravity flow of
stream 43 may not be possible.)

[0047] Depending on the quantity of heavier hydrocarbons in the feed gas and
the feed gas pressure, the cooled first and second portions 32 and 33 entering
separator section 115e in FIG. 2 or separator 11 in FIG. 8 (or the cooled feed
stream
31a entering separator section 115e in FIGS. 3 through 7 or separator 11 in
FIGS. 9
through 13) may not contain any liquid (because it is above its dewpoint, or
because it
is above its cricondenbar). In such cases, there is no liquid in stream 35 (as
shown by
the dashed lines). In such circumstances, separator section 115e in processing
assembly 115 (FIGS. 2 through 7) or separator 11 (FIGS. 8 through 13) may not
be
required.

[0048] In accordance with the present invention, the use of external
refrigeration to supplement the cooling available to the inlet gas and/or the
first
distillation vapor stream from the second distillation vapor stream and the
distillation
liquid stream may be employed, particularly in the case of a rich inlet gas.
In such
cases where additional inlet gas cooling is desired, a heat and mass transfer
means
may be included in separator section 115e (or a collecting means in such cases
when
the cooled first and second portions 32 and 33 or the cooled feed stream 31a
contains
no liquid) as shown by the dashed lines in FIGS. 3 through 7, or a heat and
mass
transfer means may be included in separator 11 as shown by the dashed lines in
FIGS. 9 though 13. This heat and mass transfer means may be comprised of a fin
and
tube type heat exchanger, a plate type heat exchanger, a brazed aluminum type
heat
exchanger, or other type of heat transfer device, including multi-pass and/or
multi-service heat exchangers. The heat and mass transfer means is configured
to

-25-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
provide heat exchange between a refrigerant stream (e.g., propane) flowing
through
one pass of the heat and mass transfer means and the vapor portion of stream
31a
flowing upward, so that the refrigerant further cools the vapor and condenses
additional liquid, which falls downward to become part of the liquid removed
in
stream 35. As shown by the dashed lines in FIGS. 2 and 8, the heat and mass
transfer
means in separator section 115e (FIG. 2) or separator 11 (FIG. 8) may include
provisions for providing supplemental cooling with refrigerant. Alternatively,
conventional gas chiller(s) could be used to cool stream 32, stream 33, and/or
stream
31a with refrigerant before streams 32 and 33 enter separator section 115e
(FIG. 2) or
separator 11 (FIGS. 8) or stream 31a enters separator section 115e (FIGS. 3
through
7) or separator 11 (FIGS. 9 through 13). In cases where additional cooling of
the first
distillation vapor stream is desired, the heat exchange means in condensing
section
115b of processing assembly 115 (FIGS. 2 through 5, 7 through 11, and 13) or
heat
exchanger 10 (FIGS. 6 and 12) may include provisions for providing
supplemental
cooling with refrigerant as shown by the dashed lines.

[00491 Depending on the type of heat transfer devices selected for the heat
exchange means in feed cooling section 115a and condensing section 115b, it
may be
possible to combine these heat exchange means in a single multi-pass and/or
multi-service heat transfer device. In such cases, the multi-pass and/or multi-
service
heat transfer device will include appropriate means for distributing,
segregating, and
collecting stream 31, stream 32, stream 33, first distillation vapor stream
38, any
vapor separated from the cooled stream 38, and the second distillation vapor
stream in
order to accomplish the desired cooling and heating.

[0050] It will also be recognized that the relative amount of condensed liquid
that is split between streams 41 and 42 in FIGS. 2 through 6 and 8 through 12
will
-26-


CA 02764282 2011-12-01
WO 2010/144172 PCT/US2010/029331
depend on several factors, including gas pressure, feed gas composition, and
the
quantity of horsepower available. The optimum split generally cannot be
predicted
without evaluating the particular circumstances for a specific application of
the
present invention. Some circumstances may favor feeding all of the condensed
liquid
to the upper region of absorbing section 115c in stream 41 and none to the
upper
region of deethanizing section 115d in stream 42, as shown by the dashed lines
for
stream 42. In such cases, the heated distillation liquid stream 43a may be
supplied to
the upper region of deethanizing section 115d to serve as reflux.

[0051] The present invention provides improved recovery of C3 components
and heavier hydrocarbon components per amount of utility consumption required
to
operate the process. An improvement in utility consumption required for
operating
the process may appear in the form of reduced power requirements for
compression or
re-compression, reduced power requirements for external refrigeration, reduced
energy requirements for tower reboiling, or a combination thereof.

[0052] While there have been described what are believed to be preferred
embodiments of the invention, those skilled in the art will recognize that
other and
further modifications may be made thereto, e.g. to adapt the invention to
various
conditions, types of feed, or other requirements without departing from the
spirit of
the present invention as defined by the following claims.

-27-

A single figure which represents the drawing illustrating the invention.

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Admin Status

Title Date
Forecasted Issue Date 2016-01-05
(86) PCT Filing Date 2010-03-31
(87) PCT Publication Date 2010-12-16
(85) National Entry 2011-12-01
Examination Requested 2015-03-26
(45) Issued 2016-01-05

Abandonment History

There is no abandonment history.

Maintenance Fee

Description Date Amount
Last Payment 2020-04-01 $250.00
Next Payment if small entity fee 2021-03-31 $125.00
Next Payment if standard fee 2021-03-31 $250.00

Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following

  • the reinstatement fee set out in Item 7 of Schedule II of the Patent Rules;
  • the late payment fee set out in Item 22.1 of Schedule II of the Patent Rules; or
  • the additional fee for late payment set out in Items 31 and 32 of Schedule II of the Patent Rules.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Filing $400.00 2011-12-01
Maintenance Fee - Application - New Act 2 2012-04-02 $100.00 2012-03-02
Maintenance Fee - Application - New Act 3 2013-04-02 $100.00 2013-03-06
Maintenance Fee - Application - New Act 4 2014-03-31 $100.00 2014-03-06
Maintenance Fee - Application - New Act 5 2015-03-31 $200.00 2015-03-04
Request for Examination $800.00 2015-03-26
Final Fee $300.00 2015-10-21
Maintenance Fee - Patent - New Act 6 2016-03-31 $200.00 2016-03-29
Maintenance Fee - Patent - New Act 7 2017-03-31 $200.00 2017-03-27
Maintenance Fee - Patent - New Act 8 2018-04-03 $200.00 2018-03-26
Maintenance Fee - Patent - New Act 9 2019-04-01 $200.00 2019-03-22
Registration of Documents 2020-01-24 $100.00 2020-01-24
Maintenance Fee - Patent - New Act 10 2020-03-31 $250.00 2020-04-01
Current owners on record shown in alphabetical order.
Current Owners on Record
S.M.E. PRODUCTS LP
Past owners on record shown in alphabetical order.
Past Owners on Record
ORTLOFF ENGINEERS, LTD.
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.

To view selected files, please enter reCAPTCHA code :




Filter Download Selected in PDF format (Zip Archive)
Document
Description
Date
(yyyy-mm-dd)
Number of pages Size of Image (KB)
Abstract 2011-12-01 2 95
Claims 2011-12-01 51 1,763
Drawings 2011-12-01 13 271
Description 2011-12-01 27 993
Representative Drawing 2011-12-01 1 24
Cover Page 2012-02-14 2 70
Claims 2015-03-26 28 907
Representative Drawing 2015-12-09 1 13
Cover Page 2015-12-09 2 71
PCT 2011-12-01 14 859
Assignment 2011-12-01 4 90
Prosecution-Amendment 2011-12-01 41 1,424
Prosecution-Amendment 2015-03-26 35 1,069
Prosecution-Amendment 2015-03-26 2 54
Prosecution-Amendment 2015-03-26 30 960
Correspondence 2015-10-21 2 50