Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02424903 2003-04-09
AMINE-ACID REACTION PRODUCTS
AS ASPHALTENE DISPERSANTS IN CRUDE OIL
Background
This invention relates generally to a method or dispersing asphaltenes 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. U.S. Pat. Application Serial No. 09/5:14,462 discloses the use
of
amine-chelate complexes to reduce the viscosity of cxwde oil. However, this
reference does not disclose a method for dispersing asphaltenes.
The problem addressed by this invention is to find materials suitable for
improving processing of petroleum products.
Statement of Invention
This invention is directed to a composition comprising: (a) 0.001% to 5% of
at least one reaction product of: (i) an amine and (ii) a carboxylic,
phosphoric or
sulfonic acid and (b) crude oih provided that the reaction product has a
hydrogen
bond donor group located two to eight chemical bonds from either (i) a
carbonyl
carbon of a carboxylic acid, a phosphorus atom of a phosphoric acid or a
sulfur
atom of a sulfonic acid or (ii) a nitrogen atom of an amino group.
This invention is directed further to a method for dispersing asphaltenes
in a petroleum product by adding to the petroleum product 0.001% to 5% of at
least one reaction product of: (i) an amine9 and (ii) a carboxylic, phosphoric
or
sulfonic acid9 and (b) crude oih provided that the reaction product has a
hydrogen
bond donor group located two to eight chemical bonds from either: (i) a
carbonyl
carbon of a carboxylic acid, a phosphorus atom of a phosphoric acid or a
sulfur
atom of a sulfonic acid or (ii) a nitrogen atom of an amino group.
CA 02424903 2003-04-09
2
Detailed Description
All percentages are weight percentages based on the entire composition,
unless otherwise indicated. A "hydrogen bond donor group" is a group capable
of
forming a hydrogen bond with an oxygen or nitrogen atom, e.g., a hydroxy,
oxime, amide, or alkyl amide functional group. An "alkyl" group is a
hydrocarbyl
group having from one to twenty-two carbon atoms in a linear, branched or
cyclic
arrangement. Alkyl groups optionally have one or more double or triple bonds.
Substitution on alkyl groups of one or more of halo, cyano, alkyl, alkoxy, or
the
aforementioned polar 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 ~, NR, 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. An "aralkyl" group is an "alkyl" group substituted by an "aryl" group.
A
"heterocyclic" group is a substituent derived from a h.eterocyclic compound
having from hve 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 the aforementioned polar groups is permitted, with substitution by
one
or more 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.
An "organic functional group" is a functional group which does not contain
metal atoms, and which has from one to twenty-two carbon atoms, hydrogen
atoms, and optionally, contains heteroatoms, including but not limited to:
nitrogen, oxygen, sulfur, phosphorus and halogen atoms. An organic functional
group 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
CA 02424903 2003-04-09
3
this invention, at least one of the organic functional groups is a C2-C22
alkyl or
heteroalkyl group, more preferably a C r-Ca2 alkyl or heteroalkyl group, more
preferably a Cs-C22 alkyl or heteroalkyl group, and most preferably, a Cr5-C2z
alkyl group.
In the present invention, at least one reaction product of an amine and an
acid is added to a petroleum product, with the total amount of said reaction
products) being from 0.001% to 5%, preferably from 0.01% to 5%, more
preferably from 0.01% to 1%, more preferably from 0.01% to 0.2%, and roost
preferably from 0.02% to 0.2%. The reaction product has no new covalent bonds,
i.e., bonds not present in the amine or the acid. The reaction product is
either a
salt or a physical mixture or complex of the amine and the acid. Preferably, a
reaction product used in this invention is a salt, preferably one that is
soluble in
oil at least at the aforementioned levels. Preferably, the salt has at least
ten
carbon atoms, more preferably at least 15 carbon atoms. Preferably a salt used
in this invention has a canon and an anion, and is not zwitterionic.
In a preferred embodiment of this invention, the acid is a carboxylic acid
having no other acidic functional groups, i.e., groups having pI~<6. In
another
preferred embodiment of this inventian, the acid is a phosp.honic acid having
no
other acidic functional groups. In another preferred embodiment of this
invention, the acid is a sulfonic acid having no other acidic functional
groups.
The separation between a hydrogers bond donor group and the carboxylic,
phosphoric ar sulfonic acid or the amine is measured by the number of covalent
chemical bonds intervening between either: (i) an oxygen of a hydroxy group or
(ii) a carbonyl or imine carbon of amide or oxime~ and one of the carboxylic
acid
carbonyl carbon, the phosphorus atom of a phosphoric acid, the sulfur atom of
a
sulfonate and the amine nitrogen atom. F'or example, in an amine salt of
glycolic
acid (hydroxyacetic acid), the oxygen of the hydroxy group is two bonds from
the
carbonyl carbon of the carboxylate group. Preferably, at least one polar group
in
a compound of this invention is located two to six chemical bonds from a
carboxylic acid carbonyl carbon, the phosphorus atom of a phosphoric acid, the
sulfur atom of a sulfonate or the amine nitrogen atom and most preferably two,
three, four or five chemical bonds from a carboxylic acid carbonyl carbon, the
CA 02424903 2003-04-09
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phosphorus atom of a phosphonic acid, the sulfur atom of a sulfonate or the
amine nitrogen atom.
A compound used in this invention optionally contains other carboxylate,
phosphonate, sulfonate or protonated imine functional groups on one or more of
the organic functional groups, preferably for a total of one to five conjugate
acid
functional groups and one to five conjugate base functional groups.
Preferably,
the compound has one conjugate acid group and one conjugate base group.
Preferably, a hydrogen bond donor group is a hydroxy or amide functional
group.
Most preferably, a hydrogen bond donor group is a hydroxy group.
In a preferred embodiment of the invention in which a salt of an amine
and a carboxylic acid is added to crude oil, the salt has formula (I),
RIRZR3~1+ Ra~00-
wherein Rl, Rz, R3 independently are hydrogen or organic functional groups,
provided that at least one is not hydrogen and R4 is an organic functional
group.
Other carboxylate groups or other protonated amine groups optionally are
present on R1, Rz, R3 or R'~. Preferably, R3, Rz, R3 and R4 independently are
hydrogen, alkyl, heteroalkyl, aryl, aralkyl or heterocyclic. Preferably, Rl,
Rz, R3
and R4 do not contain other carboxylate groups. In one preferred embodiment,
one of Rx, R2 and R3 is Cio-Czz alkyl, more preferably Caz-Czz alkyl, and most
preferably, CIS-Czz alkyl. In one preferred embodiment, the protonated amine
part of the compound of formula (I) is derived from an unsubstituted Cio-Czz
alkyl amine, RzIVHz, preferably one which is an oil-soluble amine. In one
embodiment, the alkyl amine is a tertiary alkyl primary amine, i.e., a primary
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 PrimeneTM amines available from Rohm and Haas Company, Philadelphia,
PA. Preferably, a polar group is present and is located two to ten chemical
bonds
from either: a carbonyl carbon of a carboxylate groups or a nitrogen atom of a
protonated imine group.
CA 02424903 2003-04-09
In one preferred embodiment of the invention, the carboxylate ion of a salt
used in this invention has formula (II)
5
wherein R5 and R~ independently are hydrogen, alkyl or hydroxyl X is O- or
R~R$N~ and R~ and R$ independently are hydrogen, alkyl, aryl, aralkyl or
heteroalkyl. Preferably, R~ is hydrogen arid R~ is alkyl. In one preferred
embodiment, R5 and R~ both are hydroxy and X is O-. In another preferred
embodiment, R5 is alkyl, X is R7R~N, and I~,s is hydrogen preferably, at
.least one
of R~, R7 and R$ is Cs-Cz2 alkyl, more preferably Cis-C2a alkyl. The
carboxylate
ion of formula (II) occurs in a salt with at least one protonated amine.
Preferably, the amine is an unsubstituted alkyl amine, preferably a Cis~C22
alkyl
amine.
In a preferred embodiment of this ixmention, the carboxylate ion of a salt
is selected from the group consisting of:
COz-
\
~~~~n
O
/ \O-
\ ~ NI-IR8
O
CA 02424903 2003-04-09
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R9
HR$N _
O
O
HRgN
v _O~
O
HO
HOr~ N ~_
and
L5
R12CO0-
wherein R° is hydrogen or CuC22 alkyl RI° and R11 independently
are hydrogen
or CmC2z alkyh R12 is Cis-Czz alkyh and n is one or two. Preferably, R°
:is
hydrogen or CuCs alkyl. Preferably, Rl° and Rll independently are
hydrogen or
CnCs alkyl, most preferably hydrogen, methyl or ethyl.
CA 02424903 2003-04-09
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In a preferred embodiment of the invention, the ammonium ion of a salt
used in the invention has the formula R13Ri4R15NH+, wherein R13 is C2-Cs
alkyl,
or C2-Cs heteroalkyl with one or two carbon atoms replaced by oxygen atoms,
and in either case substituted by one or two hydroxy groups and R14 and Ri5
independently are hydrogen, methyl or ethyl. Preferably, R13 is 2-hydroxyethyl
or 3-hydroxypropyl. Preferably, R14 and Ri~ are hydrogen. Preferably, the
carboxylate ion of the salt is selected from the group consisting of:
O
HRgN (RI)
_O_
O
O
I-IR$N ' ~ _ (~)
O
O
and
O-
(V)
~THRg
O
In addition to dispersing asphaltenes, the composition of the present
invention typically also increases demulsibility, redLrces sediment formation,
reduces surface fouling and reduces corrosion. For crude oil recovery, the
composition of the present invention can be injected directly into an
injection
well, or preferably diluted with solvent prior to injection. Suitable solvents
CA 02424903 2003-04-09
g
include but are not limited to: petroleum distillates such as kerosene and gas
oil;
linear and branched aliphatic solvents such as pentane, hexanes, mixtures of
nonanes and 2-ethylhexanes; cycloaliphatic mixtures commonly known as
naphtha aromatic solvents such as toluene, xylenes and commercial aromatic
solvent mixtures esters; ethers alcohols such as ethanol, isopropanol, octanol
and dodecanol; ketones such as acetone, cyclohexanone and acetophenone~ and
other polar solvents. Preferred dilutions are 0.01 to 50 wt% 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 %.
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 14-40 (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 to 24 h (Rating = 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
CA 02424903 2003-04-09
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asphaltenes occurred (Rating = 0~ poor). Results for several amine-carboxylic
acid salts are reported in the Table.
CA 02424903 2003-04-09
IO
Table
Salts
of
hvdroxy
acids
and
amines
1 salic lic acid/ole famine (l:1) salt
hexanes~ treat rate: 1000 m 2+
2 ole lamine/2-h drox isobut ric acid
salt
hexanesi treat rate: 1000 m 2+
3 ole lamine/3,4-dih drox benzoic acid
salt
hexanes~ treat rate: 1000 m 2+
4 ole lamine/bicine salt
hexanes~ treat rate: 1000 m 2+
ole lamine/citric acid 2:1 salt
hexanes~ treat rate: 1000 m 2+
6 ole lamine/citric acid 3:1 salt
hexanes~ treat rate: 1000 m 2+
Salts
of
hydroxy
amines
and
acids
7 S lfatTM FA-l/ethanolamine salt
hexanes~ 1000 m 2+
8 S lfatTM FA-1/diethanolamine salt
hexanes~ 1000 m 1
9 N-Meth 1-N-ole o 1 1 cine/ethanolamine
salt
hexanes~ 1000 m 2
ethanolaminelIII, R8= 0-16-22 (PrimeneTM
JM-T) salt
hexanes~ 2000 m 2+
Aromatic 150 1000 m 2+
11 ethanolaminelIV, R8= 0-16-22 (PrimeneTM
JM-T) salt
hexanes~ 2000 m 2+
12 ethanolamine/V, R8= 0-16-22 (PrimeneTM
JM-T) salt
hexanes> 2000 m 2+
The treat rate is the concentration of the salt in the crude 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~ this solvent, at a treat rate of 10,000 ppm has a rating of 0.
PrimeneTM amines are tertiary alkyl primary amines in which the alkyl groups
are a mixture of isomers, In PrimeneTM 81-R amine, the alkyl group is a
mixture
10 of Cio-Crs alkyl groups and in PrimeneTM JM-T amine, of Cis-Cz2 alkyl
groups.
SylfatTM FA-1 is a naturally-occurring mixture of unsaturated 018 aliphatic
acids,
available from Arizona Chemicals Co., Jacksonville, FL.
Efficacy of viscosity reduction in crude oil was assessed for salts 1-6 (1 and
2%
treat rates), ~ (2000 ppm) and 10 (4000 ppm). None of these salts reduced the
viscosity of the oil.
