Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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COMPOUNDS CONTAINING AMIDE AND CARBONYL GROUPS AS
ASPHALTENE DISPERSANTS IN CRUDE OIL
Background
This invention relates generally to compounds containing amide and
carboxyl groups. The compounds are useful in processing of crude oil.
Certain petroleum products, including heavy crude oils, which include
materials referred to as "tars," "petroleum tars" or "tar sands," are rich in
asphaltenes, metals and resins. The presence of these types of compounds can
lead to various problems in the recovery, transportation, treatment and
refining
of crude oils, including increased viscosity, formation of stable emulsions,
fouling
and corrosion. United States Patent Number 5,948,23'7 discloses a particular
class of oc-amido carboxylic acids as asphaltene dispersants, but does not
disclose
the compounds used in the present invention.
The problem addressed by this invention is to find a composition suitable
for improving processing of petroleum products.
Statement of Invention
The present invention is directed to a composition comprising: (a) 0.001%
to 20% of at least one compound having= (i) at least one carboxyl group (ii)
at
least one amide group and (iii) at least fifteen carbon atoms and (b) crude
oih
provided that the compound is not represented by formula (I)
O
OH
R
(i)
~2 O
wherein R1 and RZ independently are hydrogen or C~-C2z alkyl and n is one or
two.
This invention is directed further to a method for dispersing asphaltenes
in a petroleum product. The method comprises adding to the petroleum product
0.001% to 20% of at least one compound having: (i) a.t least one carboxyl
group9
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(ii) at least one amide group and (iii) at least fifteen carbon atoms and (b)
crude
oih provided that the compound is not represented by formula (I)
wherein Rl and Rz independently are hydrogen or Ci-Czz alkyl and n is one or
two.
Detailed Description
All percentages are weight percentages based on the entire composition,
unless otherwise indicated. An "alkyl" group is a hydrocarbyl group having
from
one to seventy carbon atoms in a linear, branched or cyclic arrangement. A
"difunctional alkyl" group is an alkyl group having two points of attachment
on
the same or different carbon atoms, e.g., -CHz-, -CHzCHz-, -CH(CH2CHzCHa)-,
and -CH2CH(CH2CHzCHs)v Alkyl groups optionally have one or more double or
triple bonds. Substitution on alkyl groups of one or more of halo, cyano,
alkoxy,
or hydroxyl groups is permitted alkoxy groups may in turn be substituted by
one
or more halo substituents. A "heteroalkyl" group is an alkyl group in which at
least one carbon has been replaced by O, 1~TR, or S, wherein R is hydrogen,
alkyl,
heteroalkyl, aryl or aralkyl,. An "aryl" group is a substituent derived from
an
aromatic hydrocarbon compound. An aryl group has a total of from six to twenty
ring atoms, and has one or more rings which are separate or fused. A
"difunctional aryl" group is an aryl group having two points of attachment,
e.g.,
o-phenylene. An "aralkyl" group is an "alkyl" group substituted by an "aryl"
group. A "heterocyclic" group is a substituent derived from a heterocyclic
compound having from five to twenty ring atoms, at least one of which is
nitrogen, oxygen or sulfur. Preferably, heterocyclic groups do not contain
sulfur.
Substitution on aryl or heterocyclic groups of one or more of halo, cyano,
alkyl,
heteroalkyl, alkoxy or hydroxy is permitted, with substitution by one or more
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halo groups being possible on alkyl, heteroalkyl or alkoxy groups. An
"aromatic
heterocyclic" group is a heterocyclic group derived from an aromatic
heterocyclic
compound. Preferably, heterocyclic groups in compounds used in this invention
are aromatic heterocyclic groups.
In the present invention, at least one compound having (i) at least one
carboxyl group (ii) at least one amide group and (iii) at least fifteen carbon
atoms is added to a petroleum product, with the total amount of said
compounds) being from 0.001% to 20%, pi°eferably from 0.001% to 10%,
more
preferably from 0.01% to 10%, more preferably from 0.01% to 1%, and most
preferably from 0.02% to 0.2%. Preferably, a compound used in this invention
is
not in the form of a salt having an anion a.nd a canon, i.e., a salt that is
not a
zwitterion~ more preferably the compound is a neutral compound. Preferably, a
carboxyl or amide functional group is not part of a heterocyclic ring.
Preferably,
a compound used in this invention is aliphatic. Preferably, a compound used in
this invention is acyclic. Preferably, compounds of formula (I) for which n is
from three to five also are excluded from the compounds of this invention.
A compound used in the composition or method of this invention
preferably is represented by formula (II),
~B)
~ O
wherein R5 is C1°C~o difunctional alkyl or CG-Ci4 difunctional aryl,
and R3 and R4
independently are hydrogen or organic functional groups. -Preferably, R3 and
R4
independently are hydrogen, alkyl, heteroalkyl, heterocyclic, aryl or aralkyl.
Preferably, at least one of R3, R4 and R5 has at least 12 carbon atoms, and
most
preferably at least 15 carbon atoms.
An "organic functional group" is a functional group which does not contain
metal atoms, and which has from one to seventy carbon atoms, hydrogen atoms,
and optionally, contains heteroatoms, including but not limited to: nitrogen,
oxygen, sulfur, phosphorus and halogen atoms. An organic: functional group
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optionally contains double and/or triple bonds rings, which are linked or
fused
and if it is wholly or partly acyclic, the acyclic part can be linear or
branched.
Preferably, an organic functional group is an alkyl, heteroalkyl, aryl,
aralkyl,
heterocyclic or heterocyclic-alkyl group. In a preferred embodiment of this
invention, at least one of the organic functional groups is a Cz-Czz alkyl or
heteroalkyl group, more preferably a Cs-Czz alkyl or heteroalkyl group, more
preferably a Cio-Czz alkyl or heteroalkyl group, and most preferably, a Cis-
Czz
alkyl group. Preferably, alkyl and heteroalkyl groups are unsubstituted. A
compound used in this invention optionally contains other carboxyl or amide
IO functional groups on one or more of the organic functional gxoups,
preferably for
a total of one to three carboxyl and/or amide functional groups. Preferably,
only
one carboxyl group and one amide group are present.
In a preferred embodiment of this invention, R~ is CnCs difunctional alkyl
in which the points of attachment are at opposite ends of the alkyl group,
e.g.,
-CHz-, -CH2CHz-, -CHzCH2CHz- and -CH=CH-. Preferably, Rs is Ci-C$
difunctional alkyl. In another preferred embodiment of this invention, R5 is
Cm
Cm difunctional alkyl in which the points of attachment are on the same carbon
of the alkyl group, e.g.,
G
R
\CH ~
wherein Rs is Cio-Cis alkyl. Preferably, Rs is Cis-Cis alkyl.
In another preferred embodiment, R5 is Cso-C~o difumctional alkyl,
preferably in which the points of attachment are on adjacent carbon atoms of
the
difunctional alkyl group, most preferably on adjacent carbon atoms at one end
of
the difunctional alkyl, i.e., -CHzCH(C~o~~o)-. Compounds of this type are
derived,
for example, from reaction of an amine with polyisobutylene succinic
anhydride,
which has a polyisobutyTlene group having from 50 to 70 carbon atoms as a
substituent on a succinic anhydride ring carbon.
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In another preferred embodiment, Ro is hydrogen and. R4 is Cio-C2z alkyl,
preferably Cls~C22 alkyl. Preferably, R4 is derived from an unsubstituted
Cls'C22
alkyl amine, R4NH2, preferably one which is an oil-soluble amine. In one
embodiment, the alkyl amine is a tertiary alkyl primary amine., i.e., a
primary
5 amine in which the alkyl group is attached to the amino group through a
tertiary
carbon. Examples of commercially available tertiary alkyl primary amines are
the PrimeneT"1 amines available from Rohm and Haas Company, Philadelphia,
PA.
In a preferred embodiment of the invention, the compound of formula (II)
is selected from the group consisting of
O
HR4N (fit)
-OH
O
O
HR4N
-OH
O
O
OH
(~)
VHR4
O
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R~ O
HR4N
OH (VI)
O
and
O R7 Rs R~ O
i' NH 'NH (VII)
HO \ OH
O O
wherein R' is Cso-C~o alkyl and R$ is C2-C22 difunctional alkyl or
heteroalkyl,
preferably Cz-Ca difunctional alkyl or heteroalkyl. Reaction of an alkyl
amine,
R4NH2 with succinic, malefic or phthalic anhydride produces a compound of
formula (III), (IV) or (V), respectively. Tertiary alkyl primary amines are
IO preferred amines for this reaction. Reaction of an alkyl amine, R4NH2 with
polyisobutylene succinic anhydride (PIBSA) produces a compound of formula
(V I), and reaction of a diamine H2NR$NH~ with PIBSA produces a compound of
formula (VII). In one preferred embodiment of the invention, Rg is C4-Cs
difunctional heteroalkyl, and preferably is derived from a diamine selected
from
IS among diethylenetriamine, triethylenetetramine and tetraethylenepentamine.
In addition to dispersing asphaltenPs, the composition of the present
invention typically also increases demulsibility, reduces viscosity, reduces
sediment formation, reduces surface fouling and reduces corrosion. For crude
oiI
recovery, the composition of the present invention can be injected directly
into an
20 injection well, or preferably diluted with solvent prior to injection.
Suitable
solvents include but are not limited to: petroleum distillates such as
kerosene
and gas oih linear and branched aliphatic solvents such as pentane, hexane,
mixtures of nonanes and 2-ethylhexanes~ cycloaliphatic mixtures commonly
known as naphtha aromatic solvents such as toluene, xylenes and commercial
25 aromatic solvent mixtures esters ethers alcohols such as ethanol,
isopropanol,
octanol and dodecanoh ketones such as acetone, cyclohexanone and '
acetophenone~ and other polar solvents. Preferred dilutions are 0.01 to 50 wt%
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of the compound in the solvent, more preferred dilutions being 0.01 to 20 wt%,
more preferred dilutions being 0.1 to 10%, and most preferred dilutions being
1
to 10 wt %.
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Examples
Performance Criteria and Test Methods=
Asphaltene Dispersancy-test tube method= This test requires a previously made
dispersion of asphaltene in xylenes (Aromatic 150 solvent) or asphaltenic
heavy
crude diluted in xylenes (Aromatic 150 solvent) at a known concentration. A
solution of an additive formulation (0.1 mL, the active ingredient was
typically
at 5-10 wt%, making the treat rate 500-1000 ppm) was taken in to a 15.0 mL
graduated glass centrifuge tube, and hexanes added such that the total volume
in the tube became 10.0 mL. To this mixture of additive and hexanes,
asphaltenic stock solution (0.1 mL) was added. The test tube was then capped,
shaken vigorously for about a minute or 40-60 times by hand and allowed to
stand. The volume of any precipitated asphaltenes settled at the bottom of the
tube was recorded at 10, 30, 60, 90 and 1440 (24 h) min intervals. When no
additive was used, the volume of asphaltenes precipitated in the first 0.5-1 h
was 0.4-0.5 mL (4-5%)~ in fact, it was important to initially adjust the
concentration of the asphaltene stock in such a way that under these
conditions
of dilution with paraffinic solvents, a 4-5 vol% of asphaltenic precipitation
occurred. When the additive was an effective dispersant of asphaltene, then no
precipitate was formed up t;o 24 h (hating = 2~ good). In some cases, no
precipitation was observed in over 24 h to several days (Rating = 2+;
excellent).
If the additive was not a dispersant, then an almost immediate precipitation
of
asphaltenes occurred (I~.ating = 0~ poor). I~,esults for two compounds having
an
amide group and a carboxyl group are reported in the Table.
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Table
com ound ratin
(III) R4 = C-16-22 (derived from PrimeneTM
~ JM-T amine)
formulated at 20% in AROMATIC 150 SOLVENT2
treat rate: 2000 m
(IV) R4 = C-16-22 (derived from PrimeneTM
JM-T amine)
formulated at 20% in AROMATIC 150 SOLVENT2
treat rate: 2000 m
The treat rate is the concentration of the compound in the exude oil.
AROMATIC 150 SOLVENT is a solvent mixture with a boiling range of 184-
204°C which contains xylene isomers, and which is available from Exxon
Mobil
Chemical Co., Houston TX.
