CA1223833A - Recycled fatty acid crude petroleum recovery system - Google Patents
Recycled fatty acid crude petroleum recovery systemInfo
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- CA1223833A CA1223833A CA000466334A CA466334A CA1223833A CA 1223833 A CA1223833 A CA 1223833A CA 000466334 A CA000466334 A CA 000466334A CA 466334 A CA466334 A CA 466334A CA 1223833 A CA1223833 A CA 1223833A
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Abstract
RECYCLED FATTY ACID CRUDE PETROLEUM RECOVERY SYSTEM
Abstract of the Disclosure A method of recovering crude oil for subsequent processing. The method contemplates the step of exposing the source of crude oil such as a subterranean petroleum reservoir or a vessel or a container of tar sands, kerogen or the like to aliphatic or carboxylic acid, preferably oleic acid, to produce a solvated crude oil mixture of reduced viscosity, This mixture is saponified by reacting it with a nucleophilic base, preferably a hydroxide of potassium or sodium, under pressure whereby to separate the solvated mixture into petroleum crude and an acid soap which migrates to an aqueous phase. The petroleum crude is separated from the aqueous soap through conventional techniques. Afterwards, a desaponification step contemplates recovery of the aliphatic or carboxylic acid for subsequent recycling in the previously mentioned exposing step. Reuse is facilitated by desaponifying aqueous soap within a high pressure containment vessel reacted with an acid suitable for donating a hydrated proton to the aqueous phase of the soap. This reconstituted acid is recycled for injection into the inputting step. Preferably carbonic acid is generated for the desaponifying step by injecting high pressure carbon dioxide within the containment vessel. By-products of the chemical reaction are separated and/or filtered as necessary to effectuate necessary purification sub-steps.
Abstract of the Disclosure A method of recovering crude oil for subsequent processing. The method contemplates the step of exposing the source of crude oil such as a subterranean petroleum reservoir or a vessel or a container of tar sands, kerogen or the like to aliphatic or carboxylic acid, preferably oleic acid, to produce a solvated crude oil mixture of reduced viscosity, This mixture is saponified by reacting it with a nucleophilic base, preferably a hydroxide of potassium or sodium, under pressure whereby to separate the solvated mixture into petroleum crude and an acid soap which migrates to an aqueous phase. The petroleum crude is separated from the aqueous soap through conventional techniques. Afterwards, a desaponification step contemplates recovery of the aliphatic or carboxylic acid for subsequent recycling in the previously mentioned exposing step. Reuse is facilitated by desaponifying aqueous soap within a high pressure containment vessel reacted with an acid suitable for donating a hydrated proton to the aqueous phase of the soap. This reconstituted acid is recycled for injection into the inputting step. Preferably carbonic acid is generated for the desaponifying step by injecting high pressure carbon dioxide within the containment vessel. By-products of the chemical reaction are separated and/or filtered as necessary to effectuate necessary purification sub-steps.
Description
122;~833 RECYCLED FATTY ACID CRUDE PETROL1l1lM RECOVERY SYSTEM
Back~round _ the Invention The present invention is generally concerned with the enhanced recovery of crude petroleum for ~ubsequent refining, distillation or the like. More 10 particularly, the present invention is concerned with a chemical method which broadly employs fat~y acids for extracting petroleum by reducing its viscosity, but which further contemplates the recycling of the fatty acid reactant.
As will be immediately recognized by those skilled in the petroleum arts, the broad science of secondary recovery has long contemplated the further extraction of petroleum ~rude from "dry" wells by the injection 20 of various solvents~ high pressure steam, or other chemicals. A variety of prior art attempts haYe been proposed for secondary recovery. A typical example includes the drilling of a plurality of radially spaced apart secondary shafts surrounding the primary 25 well, into which high pressure steam is interjected to force out petroleum residue.
,~
1223~
) T;~e term oil shale refers to a hard carbonaceous rock that can produce oil when heated to pyrolysis temperatures of approximately 800 to 1000 degrees F.
Petroleum is recovered when the shale is properly subjected to a suitable solvent. The oil precursor in such rock is a high molecular weight organic polymer called Kerogen.
1~ Kerogen obtained from the upper regions of the Colorado and Utah oil shales has an average composition, by-weight, as follows: Carbon (80.5%);
Hydrogen (10.3%); Nitrogen (2.4%); Sulpher (1%);
Oxygen (5.8%). The host rock may consist mainly of Dolomite, Calcite, Quartz and the clays. The oil shale area of most significance in the United States is the Green river formation of Colorado, Utah and Wyoming. While a small percentage of this oil shale may be mined by surface techniques, most of it will be recovered through underground mining in large room-and-pillar mines.
Major emphasis has recently been directed to both under-ground mining and above ground retorting of minerals and oil sh le. A variety ot heat treating li:Z3833 processes have be~n developed and reported in the prior art for developing and recovering suitablc petroleum extracts from both tar sands, kerogen, and 5 subterranean "dry" wells.
In the prior art it is well known to subject such petroleum bearing formations, wells or the like, to an organic solvent such as a fatty acid. Such an acid 1() tends to reduce thé viscosity of~ the captured petroleum, facilitating subsequent pumping. Fatty acids such as carboxylic long chain or aliphatic acids have been previously employed in the prior art.
Moreover, such processes have been combined with the 15 injection of high pressure steam to promote a subsequent aqueous reaction.
By using long chain carboxylic acids, productivity increases of as much as 50% or more have been 20 obtained. The inherent economics of such a situation have yet to favor its large scale application, mainly as a result of the initial cost of the presently non-recycled fatty acids. Moreover, typical crude petroleum, once contaminated with the fatty acid in 25 solution, cannot be purified by standard retorting, distilling or the like since the contaminating fatty acid will form an azeotrope with nearly every fraction~
of the desired petroleum oil. For this reason 5 virtually every major oil refinery will refuse raw crude if substantially contaminated with fatty acid(s).
Formations of oil sands are usually shallow enough 10 to allow for their removal by standard surface mining techniques, After the outcrop is suitably mined and the recovered petroleum-bearing rock transported to a processing (i.e. crushing) position, treatment of the recovered sands etc., within an agitation tank may 15 proceed by subsequent mixture with a fatty acid in aqueous solution. Agitation or heat may be additionally applied to lower the viscosity of the resulting solvated oil depending upon the temperature at which extraction is carried out. Silica and other 20 minerals yielded in this manner may be separated by gravity through use of a centrifuge or the like.
Electrolytes such as sodium cloride or potassium cloride have been added previously to sharpen this separation process. However it would seem desirable 25 to initially separate the bitumen in the very first , .. .. . ..
3L~ 23833 .step to enhance the efficiency of a secondary oil recovery system. Moreover, due to the costs of the extraction solvents, some form of system for p~oviding 5 continuous recirculation and recycling of same is malldated .
In the prior art the use.,of heavy aliphatic hydrocarbon acids and the like, including o]eic acid 10 and its derivatives, is known in secondary oil recovery. Moreover saponification reactions have yreviously occurred in conjunction with crude oil recovery systems as a by-product between the basic substances employed. Separation by the step of 15 precipitation is also well known. United States Patent 3,Q75,918 teaches the use of carbon dioxide in conjun.ction with the secondary recovery of hydro-carbon fuels. ~ Specifically, it has been suggested to employ carbon dioxide in combination with the oxides
Back~round _ the Invention The present invention is generally concerned with the enhanced recovery of crude petroleum for ~ubsequent refining, distillation or the like. More 10 particularly, the present invention is concerned with a chemical method which broadly employs fat~y acids for extracting petroleum by reducing its viscosity, but which further contemplates the recycling of the fatty acid reactant.
As will be immediately recognized by those skilled in the petroleum arts, the broad science of secondary recovery has long contemplated the further extraction of petroleum ~rude from "dry" wells by the injection 20 of various solvents~ high pressure steam, or other chemicals. A variety of prior art attempts haYe been proposed for secondary recovery. A typical example includes the drilling of a plurality of radially spaced apart secondary shafts surrounding the primary 25 well, into which high pressure steam is interjected to force out petroleum residue.
,~
1223~
) T;~e term oil shale refers to a hard carbonaceous rock that can produce oil when heated to pyrolysis temperatures of approximately 800 to 1000 degrees F.
Petroleum is recovered when the shale is properly subjected to a suitable solvent. The oil precursor in such rock is a high molecular weight organic polymer called Kerogen.
1~ Kerogen obtained from the upper regions of the Colorado and Utah oil shales has an average composition, by-weight, as follows: Carbon (80.5%);
Hydrogen (10.3%); Nitrogen (2.4%); Sulpher (1%);
Oxygen (5.8%). The host rock may consist mainly of Dolomite, Calcite, Quartz and the clays. The oil shale area of most significance in the United States is the Green river formation of Colorado, Utah and Wyoming. While a small percentage of this oil shale may be mined by surface techniques, most of it will be recovered through underground mining in large room-and-pillar mines.
Major emphasis has recently been directed to both under-ground mining and above ground retorting of minerals and oil sh le. A variety ot heat treating li:Z3833 processes have be~n developed and reported in the prior art for developing and recovering suitablc petroleum extracts from both tar sands, kerogen, and 5 subterranean "dry" wells.
In the prior art it is well known to subject such petroleum bearing formations, wells or the like, to an organic solvent such as a fatty acid. Such an acid 1() tends to reduce thé viscosity of~ the captured petroleum, facilitating subsequent pumping. Fatty acids such as carboxylic long chain or aliphatic acids have been previously employed in the prior art.
Moreover, such processes have been combined with the 15 injection of high pressure steam to promote a subsequent aqueous reaction.
By using long chain carboxylic acids, productivity increases of as much as 50% or more have been 20 obtained. The inherent economics of such a situation have yet to favor its large scale application, mainly as a result of the initial cost of the presently non-recycled fatty acids. Moreover, typical crude petroleum, once contaminated with the fatty acid in 25 solution, cannot be purified by standard retorting, distilling or the like since the contaminating fatty acid will form an azeotrope with nearly every fraction~
of the desired petroleum oil. For this reason 5 virtually every major oil refinery will refuse raw crude if substantially contaminated with fatty acid(s).
Formations of oil sands are usually shallow enough 10 to allow for their removal by standard surface mining techniques, After the outcrop is suitably mined and the recovered petroleum-bearing rock transported to a processing (i.e. crushing) position, treatment of the recovered sands etc., within an agitation tank may 15 proceed by subsequent mixture with a fatty acid in aqueous solution. Agitation or heat may be additionally applied to lower the viscosity of the resulting solvated oil depending upon the temperature at which extraction is carried out. Silica and other 20 minerals yielded in this manner may be separated by gravity through use of a centrifuge or the like.
Electrolytes such as sodium cloride or potassium cloride have been added previously to sharpen this separation process. However it would seem desirable 25 to initially separate the bitumen in the very first , .. .. . ..
3L~ 23833 .step to enhance the efficiency of a secondary oil recovery system. Moreover, due to the costs of the extraction solvents, some form of system for p~oviding 5 continuous recirculation and recycling of same is malldated .
In the prior art the use.,of heavy aliphatic hydrocarbon acids and the like, including o]eic acid 10 and its derivatives, is known in secondary oil recovery. Moreover saponification reactions have yreviously occurred in conjunction with crude oil recovery systems as a by-product between the basic substances employed. Separation by the step of 15 precipitation is also well known. United States Patent 3,Q75,918 teaches the use of carbon dioxide in conjun.ction with the secondary recovery of hydro-carbon fuels. ~ Specifically, it has been suggested to employ carbon dioxide in combination with the oxides
2~ of alkaline earth metals, the rcaction yielding carbonates thereof. Kennedy patent 2,164,459 teachcs secondary recovery in which oil and fatty acids or other emulsifying agents are employed. The latter reference points out the use of oleic compounds, and 25 discusses the concept of saponification. United ~223833 ~tates Patent 2,233,382 teaches a great deal of useful background information concerning the use of relatively high molecular weight acids in the 5 secondary petroleum recovery arts. The latter patent, while it suggest the natural occurrence of soap-like derivatives as a result of the reaction of alkaline substances, is primarily directed towards the use of esters and related cornpounds in secondary recovery.
lU United States Patent 4,224,138 i8 directed to the recovery of tar sands subsequently subjected to recovery process. The latter reference teaches the use of chemicals such as sodium hydroxide and/or other monoalkaline reagents for the removal of bitumen prior 15 to separation of the slurry. United States Patent 4,172,025 teaches the use of caustic soda to provide a slurry reaction. Other less relevant art known to us includes United States Patents 3,392,105; 4,133,381;
2,342,106; and 4,116,809.
2~
~2~333 Summary of the Invention The present invention provides a method for recovering crude oil for subsequent refining, which system contemplates a saponification-desaponification cycle for consistently re-cycling and purifying the higher order hydro-carbon acid employed to dissolve the petroleum for subsequent refining and recovery.
In one broad aspect, the invention pertains to a method for recovering crude oil for subse~uent refining which method comprises the steps of (a~ exposing a fatty acid to a source of raw crude oil, (b) agitating the fatty acid with respect to or within the crude oil to produce a solvated crude oil mixture of reduced viscosity, (c) saponifying the solvated crude oil mixture of step (b) by reacting the same with a nucleophilic base under pressure to separate the solvated crude oil mixture into pet-roleum crude and fatty acid soap which migrates to an aqueousphase, (d) separating the petroleum crude from the fatty acid soap of step (c), and (e) dasaponifying the fatty acid soap to recover the fatty acid for subsequent recycling and reuse in conjunction with step (a). The desaponification step includes the steps of (i) inputting the fatty acid soap in the aqueous phase into a high pressure containment vessel, (ii) reacting the fatty acid soap with an acid for dona'ing a hydrated proton within the vessel to reconstitute the fatty acid used in step (a), (iii) separating the reconstituted fatty acid of step (ii), and (iv) recycling the recovered fatty acid of step (iii) into step (a).
Preferably, the present invention includes the initial exposure of a higher order aliphatic or car~oxylic acid to a source of raw crude oil. This may be done by pumping such an ,t'~
~223833 acid deeply into a subterranean petroleum reservoir, either through the primary well or through adjacent secondary flood-ing shafts. This may be done along with the pumping of water or steam. Moreover, such an acid may be exposed in a suitable reaction containment vessel to tar sands, kerogen, oil shale or the like, providing same has been properly crushed and processed along conventional lines for subsequent reaction.
Preferably the acid is agitated with respect to the crude oil source, whether it be the depths of a subterranean well or an upper containment vessel. This produces a solvated crude oil mixture with reduced viscosity, suitable for pumping and subsequent chemical reaction and separation.
The latter mixture is saponified by reacting same with a nucleophilic base under pressure whereby to separate the solvated mixture into petroleum crude and an acid soap which migrates to an aqueous phase because of the presence of water.
Subsequently the petroleum crude is separated from the aqueous soap, and the aqueous soap is subjected to a desaponification reaction.
The latter reaction contemplates the high pressure exposure of the soap product to a reactive acid suitable for donating a hydrated proton within a containment vessel to re-constitute the aliphatic or carboxylic acid. In other words, in the desaponification step, the aqueous soap residue will be reconstitured in the form of the original aliphatic or carbo-xylic acid. This product may be recycled into the initial exposure step, saving the producer substantial sums otherwise 2xpended in replacing the initial acidic reagent.
A
~2Z;3~333 (3 Various by-products of the reactive system are separat~d through convel-tional processes a t pertin~nt times. For example, Silica or other sand products 5 including drilling [ragments etc. may be separated out through filtering when the initial slurry, ~or example, is extracted or pumped from the well, In the saponification stage, a process of conventiona1 settling allows water to be drained off and recycled, 10 and lleavy-weight petroleum tar may be withdrawn for shipmcnt to the ref inery. In the reverse saponification reaction an aqueous carbonate salt is produced, along with the hydrocarbon acid.
Ilydrocarbon acid dissassociates from water, and hence 15 is separated in this fashion. Conventional evaporating tanks may be employed to separate metallic or salt by-products from water, which are then returned to the well or otherwise recycled as desired.
Thus broadly, the present invention seeks to 20 provide a highly efficient and economical system for chemically recovering and processing crude oil from subterranean wells, tar sands, kerogen or oil shale deposits and the like.
Another aspect of the present invention is to :1223833 conserve the diluting or emulsifying aci~ ini-iall-employed in secondary recovery systems.
Yet another aspect of the present invention is to provide a system for recovering the surfactant i.n its original form, suitable for subsequent recycling in continual use.
Yet another aspect of the present invention is to provide a sccondary yetroleum oil recovery processing system of the character described which may be employed in conjunction with surface formations, mined or drilled oil sand, subterranean reservoirs, or strip 15 mined kerogen or tar sand regions.
The present invention seeks to provide an extremely efficient fatty acid solvent extraction process, the inherent economics of which 20 render the system financially worthwhile.
The present invention further seeks to provide a petroleum recovery system employing fatty acids, which system will eliminate the conventional 2S cost and contamination difficulties hitherto associated with their use.
~IZ;~:3833 More particularly, the present invention seeks to provide a system for enhancing the capabilities of fatty acids, but which eliminatcs much S of the hitherto prollibitive costs and contamination difficulties prcviously associated with their use in petroleum recovery.
These and other aspects of the present invcntion, 10 along with features of novelty appurt~nant thereto, will appear or becorr~e apparent in tlle course o the following descriptive sections.
Brief Description _ the Drawin~s In the following drawings, which form a part of the speciication and which are to be construed in 20 conjunction therewith, and in which like refcrencc numerals have been employed throughout wherever possible to indicate like parts in the various views:
Figure 1 is a basic, generalized 10w diagram 25-illustrating the process of the present invention;
~' `
lZ238~3 Figure 2 is a fragmentary, pictorial, flow diagram illustrating one example of the present invention;
and, Figure 3 is a view similar to Figure 2, illustra~ing an alternative example, appearing with Fig. 1.
1() Detailed De~criPtion of the Drawin~s With initial reference now to Figure 1 of the lS drawings, the basic system 10 contemplated by the present invention broadly contemplates a source of raw petroleum 12. This source 12 may be a subterranean well, an abo've ground crude oil retort, a tar sand deposit, or a kerogen containment vessel or the like.
20 A source of fatty acid, generally designated by the reference numeral 14, is employed to subject or expose raw petroleum or the like within source 12 for subsequent solvation and consequent viscosity reduction. As used herein, the term "fatty acid"
25 shall be taken to mean a straight chain ~r branched ~Z23833 hydrocarbon comprised of not less than five carbon atoms, and characterized by at least one carboxylic-moiety such as may be generally referred to as higher 5 aliphatic or carboxylic acids. A general formula for the acids contemplated in the initial step is:
R - C - OH
1~ where "R" rcpresents a substituted or an unsubstituted aliphatic group.
The particular fatty acid may be forced into a below-ground formation through a conventional above-15 ground pumping station in a manner best suited to theparticular strata. A plug of water, steam, gas or the like may follow to force the acid through the reservoir fo~mation. Adsorbtion to matrix material around and within the lower subterranean reservoir 2~ will be reduced by the acid. The amount of acid required will depend primarily upon the permeability of the formation to water, and the viscosity of the crude petroleum to be diluted. If a given formation is highly permeable to water, less oil will be able to 25 move through it, and hence such a formation will ., ~
1.223~333 produce below its potential. However, the addition of a fatty acid will increase the permeability of the formation.
In the case of bitumen sands, standard mining techniques are usually sufficient because of their shallowness. Above ground treatment with a fatty acid may take place in source 12 in a conventional 10 containment vessel. Mixture may occur for example, in a conventional agitation tank, although agitation must not be extremely hard and vigorous.
Thus a solvated mixture of fatty acids and 15 dissolved petroleum will be received from source 12 via pipe 16 for agitation and/or settling within a suitable vessel 18. Silica, sand or other mineral solids may be filtered and removed via typical conveyor 20. The solution of fatty acid and crude 20 petroleum will be transmitted to another high pressure containment vessel 25 through line 24.
The first stage in the separation process contemplated by the present invention involves a Z5 saponification step wherein the solvated mixture ~223833 incoming to containment vessel ~5 Lhrougl-l lin~ 24 is reacted with nucleophilic base under pressure whereby to produce a solution including petroleum 5 crude and a fatty acid soap which migrates to an aqueous phase. This occurs when a strong base from the container 2~ is inputted to vessel 25. Mild agitation increases the extent of the emulsification of the petroleum by-product. The resulting fatty acid 10 soap selectively migrates to the aqueous phase, leaving behind the petroleum.
Thus a conventional phase separator 30 may be employed to output the recovered crude along line 32.
15 Waste water may be outputted along line 33. Fatty acid soaps are transmitted via line 40 to a high pressure containment vessel 42 in which desaponification occurs by subjecting the aqueous fatty soap to a suitable acid. Preferably, the acid 20 is formed from its gaseous derivative through a source 44 interconnected with vessel 42 via a valved conduit 46. For example, where reactor 42 is to subject the aqueous fatty acid soaps to desaponification through reaction with carbonic acid, high pressure carbon 25 dioxide is applied through line 46.
3L;~238~3 ]6 The acids suitable for desaponifi~ation will be discussed in detail hereinafter. However, such an acid basically must be sufficient to donate a hydrate~
5 proton within vessel ~2 to the fatty acid soap solution whereby to reconstitute the fatty acid, allowing it to be separated within conventional phase separator 50 and returned to the original fatty acid vessel 14 via line 51. Various by-products including 10 precipitates, electrolytes, and salts are recovered via line 54, and are subjected to the conventional evaporation tank 56 for the outputting of solid metals via line 57 into hopper 58 and the possible recovery of water witnin condenser 60 which may be returne(l 15 through filter 61 and pump 62 via line 65 and valve 64 back to saponification vessel 25.
Suitable fatty acids include caproic, caprylic, capric, lauric, myristic, palmitic, stearic, 20 arachidic, behinic, and lignoceric acids. The aforementioned alkanoic acids may be derived from natural products, and are hence even-nuMbered in carbon atoms (a consequence of the acetyl grouping).
It should also be noted that homologues thereof having 25 odd numbers of carbon atoms would also function, since ~Z;~3~333 the property for which they are chosen does not depend upon whether or not there are n carbon atoms or (2n-1) carbon atoms.
s Mono and Poly alkanoic acids from 3 to ~5 carbons in length may be used, although extreme branching in unsaturation will reduce the melting points. ~Iydro-alkanoic acids may also be used, but since they have 10 lligh melting points, use at standard te~perature and prcssure will be difficult. For example, hydroxybutanoics melts at fifty degrees cerltigrade.
Alkanedioics has even higher melting points; Melonic melts at 135 degrees centigrade. Alkanoics such as 15 Oleic acid, Petroseladic acid (which is the trans isomer of oleic acid) as well as most other octedecenoic acids are liquid at room temperature and hence are suggested. Linoleic acid, Trienoic acids, such as alpha-linoleic acid, and gamma-linoleic acid, 20 are also suggested. Tetranoic acid works at relatively high temperatures.
Addition of a hydrohalic acid (HX) will result in bimolecular nucleophilic substitution with inversion 25 of configuration, although stereochemical ~1223833 considerations are not important in this particular reaction sequence:
RCHOHCH2OH + HX = RCHXCH2OH ~ RCHOHCH2X
major product Derivatives of the aforementioned fatty acids would be acceptable. Such derivatives, for example, may be employed by substitution of an electron 10 withdrawing or electro-negative variety. Such derivatives could include halogens, amine derivatives, hydroxyl and alkoxy derivatives, keto derivatives, aldehyde moieties and carbonate derivatives. As used herein, the term "derivative" shall refer to the 15 latter substitution products. Derivatives may be synthesized by the reduction of the carboxyl terminus to an alcohol group with a powerful reducing agent such as aluminum lithium hydride, followed by acid catalyzed dehydration:
RCH=CH2 - ~ RCHOHCH20H
Any nucleophilic derivative of the above 25 substituents can be used to add these groups at the ~2Z383~
~(~
t)eta ~o~ition. For example, RCHOHCH20H + NaNH2 = RCHNH2CH20H + RCHOHCH2NH2 sodamide major product Addition of potassium permanganate ( ~MnO4 ) in aqueous solution will oxidize the primary alcohol back 10 to a carboxyl function:
RCHXCH2OH - ~ RCHCO0H
KMnO4 lS Where beta-halogens are involved, care must be taken to prevent an excess of acid to develop in solution, which could result in an elimination reaction, reforming the terminal alkene.
Amine derivatives would react similarly:
RCHNH2CH2OH ~ RCHNH2COOH
KMnO4 ~223833 2~
Tests using oleic acid have proved the validity of the proposed process. This material has the advan~age o being inexpensive and readily available. The 5 oleates formed during saponification are stable, nontoxic, and easily handled and transported.
Un.saturatiorl at ~ 9 could decrease the stability of this mo1ccule, especially during pressuriYed treatment with carbonic acid. The result could be addition to 1() either C9 or ClO of an alcohol moiety, or cleavage at C9 forming octanoic acid and octanedioic acid (both of which are also good extractants). Saturated fatty acids greater than four carbons in length can also be used, and may endure more cycles through the process 15 than unsaturated homologues.
Substitution of the fatty acid may be helpful in weakening its acidic carboxyl function, if the substitution is carried out adjacent to or within 5 to 2U l~ carbon lengths of the terminal carboxy moiety.
With a weakened fatty acid, i.e., one to which an a~id proton will bind more rigorously, recovery of ~he fatty acid from an aqueous solution o~ its conjugate base will require less concentra~e(l solutions of ~5 lowry-l~ronsted acids. In the case of the carl)on ~ZX~333 dioxide-carbonic acid system, this would reduce the pressure of carbon dioxide needed to bring about conversion in a given time interval.
Substitutents capable of exerting an effect on the acidity of a fatty acid as described above must be of the electron donating or "soft" type. Examples are:
Alkyl side chains; branched and straight chain;
Nitroso;
Nitrate;
Carbonate;
Aryl;
Benzyl;
Primary or Secondary Alkynyl;
Primary Alkenyl;
Sulfites;
Sulfates;
Phosphates, Phosphites;
Pyrophosphates;
Thiosulfates;
Nitriles;
Aldehydes; and, Esters.
i ,1 ~ ~23~333 In addition to making the fatty acid much easier to desaponify, these substituents, when attached at the aforementioned positions, will cause initial S removal of the acid proton co become more difficult.
If a strong base, such as sodium hydroxide or potassium hydroxide, is used in the saponification procedure, then the effect should not hinder the process.
A second group of fatty acid substitucnts may be introduced to increase the acidity of the carboxyl ¦hydrogen, and hence, allow the use of weaker, less expensive bases for saponification separation. Such 15 substituents would be of the electron withdrawing or "electronegative" variety, and, as with the soft functions, must be attached within 5 to lO carbons of the primary carboxyl moiety, and preferably adjacen~
to it. They act to lessen the electron density of ~() basic oxygen, and therefore relax the powerful bond between this oxygen and its acidic proton. The result is a stronger acid, which will undergo saponificatio more readily than an unsubstituted homologue.
¦Examples of substituents capable of increasing the ¦~5 acid strength of a fatty acid include halogens and llamines (-NH2, NRH,-NR2);-SH;-OR;-OH;-NHCOCH3;-CC13.
~223~3~13 2~
Addition of the correct substitucnt coul~ al~OW
use o Ca] cium Carbonate or lime (tlle world's L~ast expensive base) to achieve saponification, further 5 reducing long term operating costs.
The saponification step preferably includes the use of a low cost base, such as calcium oxide (lime), potassium hydroxide, or sodium hydroxide. Ral)id 10 saponification of unsubstituted, mono substituted atty aci-l derivatives of the type previously specified occurs when treated with a "strong" base such as sodium and/or potassium hydroxides; ammonia or alkoxide, salts; hydrides; and soluble suphides.
15 Stoichiometric considerations during saponification are critical. The amount of fatty acid contained in the extracted sample of petroleum must be known with substantial precision to ensure that the proper amount of base is added. If excess base in inadver~antly 20 added, quantities of untreated fatty acid will bc retained in the oil as a contaminant.
With regard to saponification unsubstitued fa~l:v acids such as 18:1~ 9 require the use of fairly 25 powerful nucleophilic bases in order for ~ 2Z~333 saponification to occur spontaneously. Such bases inclu~e:
Sodium Hydroxi(le;
Potassium Hydroxide;
Ammonia (anhydrous or in concentrated aqueous solution);
Sodium or potassium methoxide (or any salt containing methoxide);
~ Sodium, potassium ethoxide (or any salt containing ethoxide);
Group ]a Hydrides;
Tertiary Amines; (NR3) Secondary Amines; (HR2H) Primary Amines; (NH2R)2 Sodium Amide;
Potassium Amide;
Hyd r a~ine; and, Piper:idine.
~() Substitution of more electronegative functions in the vicini~y of the alpha carbon a]low use of ~he following bases:
Calcium Carbonate; Sodium Carbonate;
Sodium Bicarbonate; and, Calcium Oxide (lime).
1 2Z3~333 It has beel- demonstrated that the addition of small amounts of heat quickens the penetration of fatty acid into the pctroleum. For application to S existing wells, this poses no problem, since formation temperatures are usually quite high.
When free petroleum is presented for extraction, however, heat must be added to bring the temperature 10 to between 30 and 100 degrees C. The amount of heat needed is small enough to economically be created by burning small quantities of extracted petroleum. At this stage, no pressurization is required. Carbonic acid is a preferred saponification reagent. An 15 important limitation arises concerning the physical chemistry of carbon dioxide. At certain temperatures and pressures this 8as liquifies and no further compression can be accomplished. As reactor temperature increases, the "critical pressure", which ~0 represents the maximum allowable pressure, is pushed upward. However, it is important to keep in mind that as one increases the temperature the maximum allowable pressure increases, but the solubility of carbonic acid could decrease. As is seen from studying the 25 equation which describes solubility, it is the ratio ~223833 of pressure to temperature which actually determines the amount of carbonic acid generated in aqueous solution. As can be seen from the following table, 5 any combination of temperature and pressure conditions below or on the li.quid-vapor equilibrium line alld solid vapor line as seen on a plot of the following table can be used in the process described herein.
Log Pat atmTemp C Temp X P/T(atm K 1) 1.80 63.125 298 0.21 2.00 100.050 323 0.31 2.15 141.375 348 0.41 152.30 199.5100 373 0.53 2.40 251.2125 398 0.63 2.50 316.2150 423 0.75 2.55 354.8175 448 0.79 2.~0 398.1200 473 0.84 202.75 562.3225 498 1.13 2.80 631.0250 523 1.21 2.90 794.3275 548 1.45 2.95 891.3300 573 1.56 Desaponification occurs within vessel 42 when the ~223833 aqueous soap solution arriving from conduit 40 is subjected to acid and water therewithin. Hydronium ions will be formed.
Protonated solvent molecules will react with the soap to reconstitute the original fatty acid.
(i) GH + H2(l) G(aq) 3 (aq) ( ) 3 (aq) ,(aq) (1) (aq) 2 Above, GH represents a gas or other reagent which will, react with a solvent, in a prescribed manner to yield a hydrated proton, which, in turn, reacts with the aqueous salt, liberating a free fatty acid.
The driving force of equation (ii) is an equilibrium being made continually favourable to the right by the dissolution of fatty acids. Substances capable of acting as GH reagents include:
hydrohalic acids; hydrocyanic acids; hydrogen peroxide (may produce destructive radicals); nitric acid; nitrous acid; sulfuric acid;
sulfurous acid; phosphoric acid, phosphorous acid; acetic acid;
formic acid; propionic acid~ butyric acid; carbon dioxide; chlorous acid; chloric acid; hypochlorous acid; perchloric acid;
~2;~ 33 2~
I'erchlorous Acid; ()ther Stron~ Oxy Aci(ls;
Pic~ic Aci~; and, Ammonium compounds of the formula ( (NH4)nX-n ).
s Although the cited chemicals include large families of reagents, carbon dioxide may be the least expensive to use on an industrial scale. Its reaction l~ with water yields carbonic acid:
C02( ) ~ H2(l) = H2C03( ) ; k=2.6 X 10-3 lS Carbonic Acid will then react with water to produce the hydrated proton: (k= 4.3 X 10-7) H2C03 + H20 = HC03 H30 (aq) (1) (aq) (aq) This will react with the soap according to the 20 reverse saponification relation. The concentration of carbcnic acid depends upon the pressure of carbon dioxide (at constant temperature).
~ H 2C0 3 ) = ~_) f H CO
) Wher~ ( ) repres~nls concen~ratioll in.noles ~r liter,fH2C~ is the equilibrium formatioll const~nt ol carbonic acid from carbon dioxide and liqu:id water, S i5 the perfect gas constant, T is the absolute temperature, and PC02 is the partial pressure of carbon dioxide in units which agree with R.
The above equation is valid and applies to all conditions at which carbon dioxide is in the vapour 1~ pllase. Note that carbon dioxide may be added to the process in the liquid, or solid phase, or in any manner, including dissolving the gas in rnetals or other materials, which will produce the dissolved gas in aqueous solution, thereby generating carbonic acid.
Species which directly generate a proton by dissociation are added as the pure gas, liquid, or dissolved in aqueous or nonaqueous solution. rheir reaction would be more direct. For example, hydrohalic acids react in two steps as follows:
(aq) H2(l) = H30 (aq) + X~( (aq) + H30 (aq) = RCOOH(l) + Na+
After all chemical reactions have taken place, the excess proton yielding material is drained off to be used again, and ~he solution which now con~ains water, ~223~333 e]ectrolytes, traces of unreacted soap, and free fatty acid, is passe~ through a phase scparating dcvice, allowing the fatty acid to be collected, ~)ut r) permitting the aqueous phase to flow through. The fatty acid is then recycled back to the oil field, in thc case of reservoir apylications, or back to the inltial treatment tank in the case of mined or drilled tar sands.
1~
EXAMPI,E I:
With reference now to Figure 2 of the drawings, petroleum oleic acid mixtures enter the process lOA
15 from pipe 80 and are combined with water from pipe 82 in settling tank 84. Agitation device 86 is thell engaged, along with heating element 88. Any contaminating particles from the petroleum will be removed. Agitator 86 is then disengaged, allowing ~0 contaminants to settle to the bottom of vessel 84, being outputted through valved line 80. Mined oil sands can be directly added to vessel 84 after the majority of sediments have been separated. Pump 92 moves the biphasic mixture to phase separator 94.
~5 Water is then removed through pipe 99 to be recyc~ed back to tank 84.
~ZZ3833 Petrol~um and oleic acids flow through pipe 100 into saponification tank 102. A strong base, iOe., KOH
or NaOH is injected via line 103. The mixture 104 is 5 gently agitated by conventional stirrer apparatus 108 for a few minutes. Because this process is highly exothermic, some of the heat may be collected and returned to tank 84, i.e. tanks 102 and 84 should be mechanically disposed in heat exchange relation.
The saponified mixture is then moved to separator 111 in which it is pas~ed over a teflon grid. The petroleum will stick and is collected through line 112 and valve 113. The saponified fatty acid flows over 15 and through this grid, out pipe 116 and into pressure vessel 118 with pinvalve 122 open. Tank 118 must be constructed of molybdenum steel or some other alloy able to withstand internal pressures in excess of 1000 atmospheres.
Carbon dioxide is added through pipe 120 from source 123 at the desired pressure. Heat may then be added through coils 124 (or may be exchanged from tank 102). After a few minutes, valve 122 is opened, releasing the pressure inside tank 118. This is ~2Z3B33 carbon clioxide gas, and can be collected for reuse? or released.
Inside phase separator 130 oleic acids are sel)arated from the remaining aqueous solution over a teflon grid in separator 111~ The a~ueous layer is removed through ~ipe 133 and may be recycled to tank 84. The olcic acid flows through return pipe 140 ]0 Drum drying at 142 may be required before it is sen~
back to the well site via return line 144.
EXAMPLE II:
Figure 3 represents a refinement of the same process illustrated in Figure 2 with an emphasis on enery conservation.
Raw petroleum-oleic acid mixtures enter through 2() pipe 150 to settling tank 152. Water is addcd through pipe 154. The mixture is then agita~ed by ro~or 156.
~leat may be added through coil 158. Af~er a few minutes, agitation is stopped, and the phases are allowed to separate. At this point, all sedimentary 25 contaminants will have settled to the bottom of tank 152 and may be disposed through cleaning port 160.
:1223B33 lluid pump 164 then moves the combined phases into yhase separator 166. Water is removed through pipe 168 to be reused in tank 152, Petroleum and oleic acids 5 travel through pipe 170 into tank 172 which is constructed so as to surround tank ]76.
An alkaline base is added through pipe 179 and gentle agitation is produced by apparatus 180.
10 Sufficient heat should be generated to speed the process in tank 176.
~ fter a few minutes, the contents of tank 172 are transferred via line 184 to phase separator 186, a 15 teflon grid separator. Petroleum is removed to the refinery through pipe 180.
The oleic acid flows through valve 195 into tank 176 with release valve 197 open. Carbon dioxide from 2~ a reservoir at the end of pipe 200 flows into tank 176. When the desired pressure has been established, valve 202 is closed and the mixture is allowe~ to react for several minutes. Small heat exchange fins may be attached to tank 176 such that they protru(le 25 into tank 172 to promote heat exchange. As before, tank 176 must be constructed so as to contain pressures at least as large as 1000 atmospheres.
When valve 209 is opened, pressures inside will force the contents of tank 176 into phase separator 212. The excess carbon dioxide can be recovered or released.
Separator 212 is designed such that the aqueous phase may be collected through valve 213 while the fatty acid is recovered through valve 215 to be recycled back to the petroleum well site.
EXAMPLE III
The fatty acid is added to petroleum or oil sands in an amount which will sufficiently reduce the viSC08ity S0 as to simplify recovery. The amount 20 added must be recorded with precision, since the following saponification step requires adherence to a stoichiometric relation:
R - C - OH + KOH = R - C - OK + H20 O O
. ~
~22~833 In this instance, the stoichiometric coefficients are unity for all involved species. The same is trué
of sodiurn hydroxide or ammonia when used as S saponifying agents:
R - ICI - OH + NaOH = R - C - ONa = HzO
o Il NH3 R ICI ONH4 O O
If a chlorinated fatty acid is used for viscosity 1(~ reduction, less expensive bases, such as lime (calcium oxide) may be used:
2R-C- C - OH + CaO = (R-C-C-O-)2Ca + H2O
Cl O Cl O
Although calcium soaps are generally not very water soluble, addition of the halogen moieties near the alpha terminus tend to reverse this because of their effect of changing the electronic distribution, and therefore, adding to the yolarity of the molecule.
20 In such case, the stoichiometry demands only half as much base per equivalent weight of Latty acid. The use of sodium carbonate would also produce this same relation:
Ccl Cl 2R- - C - OH + Na2CO3 = 2R-C - C - ONa + H2O + CO2 Cl O Cl O
~23833 :3() Ihe ~hird step of tlle process uses carbonic ~ci(J
under pressure to recover the free fatty acid:
R - C - OH - CO + H O = NaHCO = R-C - OH
~ 2 2 3 ~
The stoichiometry would be the same for halogenated fatty acids.
From the foregoing, it will be seen that this 1(~ inventi,on is one well adapted to ohtai,n all the ends and objects herein set forth, together with other advantages which are obvious and which arc inherent to the structure.
It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be 25 interpreted as illustrative and not in a limiting sense.
lU United States Patent 4,224,138 i8 directed to the recovery of tar sands subsequently subjected to recovery process. The latter reference teaches the use of chemicals such as sodium hydroxide and/or other monoalkaline reagents for the removal of bitumen prior 15 to separation of the slurry. United States Patent 4,172,025 teaches the use of caustic soda to provide a slurry reaction. Other less relevant art known to us includes United States Patents 3,392,105; 4,133,381;
2,342,106; and 4,116,809.
2~
~2~333 Summary of the Invention The present invention provides a method for recovering crude oil for subsequent refining, which system contemplates a saponification-desaponification cycle for consistently re-cycling and purifying the higher order hydro-carbon acid employed to dissolve the petroleum for subsequent refining and recovery.
In one broad aspect, the invention pertains to a method for recovering crude oil for subse~uent refining which method comprises the steps of (a~ exposing a fatty acid to a source of raw crude oil, (b) agitating the fatty acid with respect to or within the crude oil to produce a solvated crude oil mixture of reduced viscosity, (c) saponifying the solvated crude oil mixture of step (b) by reacting the same with a nucleophilic base under pressure to separate the solvated crude oil mixture into pet-roleum crude and fatty acid soap which migrates to an aqueousphase, (d) separating the petroleum crude from the fatty acid soap of step (c), and (e) dasaponifying the fatty acid soap to recover the fatty acid for subsequent recycling and reuse in conjunction with step (a). The desaponification step includes the steps of (i) inputting the fatty acid soap in the aqueous phase into a high pressure containment vessel, (ii) reacting the fatty acid soap with an acid for dona'ing a hydrated proton within the vessel to reconstitute the fatty acid used in step (a), (iii) separating the reconstituted fatty acid of step (ii), and (iv) recycling the recovered fatty acid of step (iii) into step (a).
Preferably, the present invention includes the initial exposure of a higher order aliphatic or car~oxylic acid to a source of raw crude oil. This may be done by pumping such an ,t'~
~223833 acid deeply into a subterranean petroleum reservoir, either through the primary well or through adjacent secondary flood-ing shafts. This may be done along with the pumping of water or steam. Moreover, such an acid may be exposed in a suitable reaction containment vessel to tar sands, kerogen, oil shale or the like, providing same has been properly crushed and processed along conventional lines for subsequent reaction.
Preferably the acid is agitated with respect to the crude oil source, whether it be the depths of a subterranean well or an upper containment vessel. This produces a solvated crude oil mixture with reduced viscosity, suitable for pumping and subsequent chemical reaction and separation.
The latter mixture is saponified by reacting same with a nucleophilic base under pressure whereby to separate the solvated mixture into petroleum crude and an acid soap which migrates to an aqueous phase because of the presence of water.
Subsequently the petroleum crude is separated from the aqueous soap, and the aqueous soap is subjected to a desaponification reaction.
The latter reaction contemplates the high pressure exposure of the soap product to a reactive acid suitable for donating a hydrated proton within a containment vessel to re-constitute the aliphatic or carboxylic acid. In other words, in the desaponification step, the aqueous soap residue will be reconstitured in the form of the original aliphatic or carbo-xylic acid. This product may be recycled into the initial exposure step, saving the producer substantial sums otherwise 2xpended in replacing the initial acidic reagent.
A
~2Z;3~333 (3 Various by-products of the reactive system are separat~d through convel-tional processes a t pertin~nt times. For example, Silica or other sand products 5 including drilling [ragments etc. may be separated out through filtering when the initial slurry, ~or example, is extracted or pumped from the well, In the saponification stage, a process of conventiona1 settling allows water to be drained off and recycled, 10 and lleavy-weight petroleum tar may be withdrawn for shipmcnt to the ref inery. In the reverse saponification reaction an aqueous carbonate salt is produced, along with the hydrocarbon acid.
Ilydrocarbon acid dissassociates from water, and hence 15 is separated in this fashion. Conventional evaporating tanks may be employed to separate metallic or salt by-products from water, which are then returned to the well or otherwise recycled as desired.
Thus broadly, the present invention seeks to 20 provide a highly efficient and economical system for chemically recovering and processing crude oil from subterranean wells, tar sands, kerogen or oil shale deposits and the like.
Another aspect of the present invention is to :1223833 conserve the diluting or emulsifying aci~ ini-iall-employed in secondary recovery systems.
Yet another aspect of the present invention is to provide a system for recovering the surfactant i.n its original form, suitable for subsequent recycling in continual use.
Yet another aspect of the present invention is to provide a sccondary yetroleum oil recovery processing system of the character described which may be employed in conjunction with surface formations, mined or drilled oil sand, subterranean reservoirs, or strip 15 mined kerogen or tar sand regions.
The present invention seeks to provide an extremely efficient fatty acid solvent extraction process, the inherent economics of which 20 render the system financially worthwhile.
The present invention further seeks to provide a petroleum recovery system employing fatty acids, which system will eliminate the conventional 2S cost and contamination difficulties hitherto associated with their use.
~IZ;~:3833 More particularly, the present invention seeks to provide a system for enhancing the capabilities of fatty acids, but which eliminatcs much S of the hitherto prollibitive costs and contamination difficulties prcviously associated with their use in petroleum recovery.
These and other aspects of the present invcntion, 10 along with features of novelty appurt~nant thereto, will appear or becorr~e apparent in tlle course o the following descriptive sections.
Brief Description _ the Drawin~s In the following drawings, which form a part of the speciication and which are to be construed in 20 conjunction therewith, and in which like refcrencc numerals have been employed throughout wherever possible to indicate like parts in the various views:
Figure 1 is a basic, generalized 10w diagram 25-illustrating the process of the present invention;
~' `
lZ238~3 Figure 2 is a fragmentary, pictorial, flow diagram illustrating one example of the present invention;
and, Figure 3 is a view similar to Figure 2, illustra~ing an alternative example, appearing with Fig. 1.
1() Detailed De~criPtion of the Drawin~s With initial reference now to Figure 1 of the lS drawings, the basic system 10 contemplated by the present invention broadly contemplates a source of raw petroleum 12. This source 12 may be a subterranean well, an abo've ground crude oil retort, a tar sand deposit, or a kerogen containment vessel or the like.
20 A source of fatty acid, generally designated by the reference numeral 14, is employed to subject or expose raw petroleum or the like within source 12 for subsequent solvation and consequent viscosity reduction. As used herein, the term "fatty acid"
25 shall be taken to mean a straight chain ~r branched ~Z23833 hydrocarbon comprised of not less than five carbon atoms, and characterized by at least one carboxylic-moiety such as may be generally referred to as higher 5 aliphatic or carboxylic acids. A general formula for the acids contemplated in the initial step is:
R - C - OH
1~ where "R" rcpresents a substituted or an unsubstituted aliphatic group.
The particular fatty acid may be forced into a below-ground formation through a conventional above-15 ground pumping station in a manner best suited to theparticular strata. A plug of water, steam, gas or the like may follow to force the acid through the reservoir fo~mation. Adsorbtion to matrix material around and within the lower subterranean reservoir 2~ will be reduced by the acid. The amount of acid required will depend primarily upon the permeability of the formation to water, and the viscosity of the crude petroleum to be diluted. If a given formation is highly permeable to water, less oil will be able to 25 move through it, and hence such a formation will ., ~
1.223~333 produce below its potential. However, the addition of a fatty acid will increase the permeability of the formation.
In the case of bitumen sands, standard mining techniques are usually sufficient because of their shallowness. Above ground treatment with a fatty acid may take place in source 12 in a conventional 10 containment vessel. Mixture may occur for example, in a conventional agitation tank, although agitation must not be extremely hard and vigorous.
Thus a solvated mixture of fatty acids and 15 dissolved petroleum will be received from source 12 via pipe 16 for agitation and/or settling within a suitable vessel 18. Silica, sand or other mineral solids may be filtered and removed via typical conveyor 20. The solution of fatty acid and crude 20 petroleum will be transmitted to another high pressure containment vessel 25 through line 24.
The first stage in the separation process contemplated by the present invention involves a Z5 saponification step wherein the solvated mixture ~223833 incoming to containment vessel ~5 Lhrougl-l lin~ 24 is reacted with nucleophilic base under pressure whereby to produce a solution including petroleum 5 crude and a fatty acid soap which migrates to an aqueous phase. This occurs when a strong base from the container 2~ is inputted to vessel 25. Mild agitation increases the extent of the emulsification of the petroleum by-product. The resulting fatty acid 10 soap selectively migrates to the aqueous phase, leaving behind the petroleum.
Thus a conventional phase separator 30 may be employed to output the recovered crude along line 32.
15 Waste water may be outputted along line 33. Fatty acid soaps are transmitted via line 40 to a high pressure containment vessel 42 in which desaponification occurs by subjecting the aqueous fatty soap to a suitable acid. Preferably, the acid 20 is formed from its gaseous derivative through a source 44 interconnected with vessel 42 via a valved conduit 46. For example, where reactor 42 is to subject the aqueous fatty acid soaps to desaponification through reaction with carbonic acid, high pressure carbon 25 dioxide is applied through line 46.
3L;~238~3 ]6 The acids suitable for desaponifi~ation will be discussed in detail hereinafter. However, such an acid basically must be sufficient to donate a hydrate~
5 proton within vessel ~2 to the fatty acid soap solution whereby to reconstitute the fatty acid, allowing it to be separated within conventional phase separator 50 and returned to the original fatty acid vessel 14 via line 51. Various by-products including 10 precipitates, electrolytes, and salts are recovered via line 54, and are subjected to the conventional evaporation tank 56 for the outputting of solid metals via line 57 into hopper 58 and the possible recovery of water witnin condenser 60 which may be returne(l 15 through filter 61 and pump 62 via line 65 and valve 64 back to saponification vessel 25.
Suitable fatty acids include caproic, caprylic, capric, lauric, myristic, palmitic, stearic, 20 arachidic, behinic, and lignoceric acids. The aforementioned alkanoic acids may be derived from natural products, and are hence even-nuMbered in carbon atoms (a consequence of the acetyl grouping).
It should also be noted that homologues thereof having 25 odd numbers of carbon atoms would also function, since ~Z;~3~333 the property for which they are chosen does not depend upon whether or not there are n carbon atoms or (2n-1) carbon atoms.
s Mono and Poly alkanoic acids from 3 to ~5 carbons in length may be used, although extreme branching in unsaturation will reduce the melting points. ~Iydro-alkanoic acids may also be used, but since they have 10 lligh melting points, use at standard te~perature and prcssure will be difficult. For example, hydroxybutanoics melts at fifty degrees cerltigrade.
Alkanedioics has even higher melting points; Melonic melts at 135 degrees centigrade. Alkanoics such as 15 Oleic acid, Petroseladic acid (which is the trans isomer of oleic acid) as well as most other octedecenoic acids are liquid at room temperature and hence are suggested. Linoleic acid, Trienoic acids, such as alpha-linoleic acid, and gamma-linoleic acid, 20 are also suggested. Tetranoic acid works at relatively high temperatures.
Addition of a hydrohalic acid (HX) will result in bimolecular nucleophilic substitution with inversion 25 of configuration, although stereochemical ~1223833 considerations are not important in this particular reaction sequence:
RCHOHCH2OH + HX = RCHXCH2OH ~ RCHOHCH2X
major product Derivatives of the aforementioned fatty acids would be acceptable. Such derivatives, for example, may be employed by substitution of an electron 10 withdrawing or electro-negative variety. Such derivatives could include halogens, amine derivatives, hydroxyl and alkoxy derivatives, keto derivatives, aldehyde moieties and carbonate derivatives. As used herein, the term "derivative" shall refer to the 15 latter substitution products. Derivatives may be synthesized by the reduction of the carboxyl terminus to an alcohol group with a powerful reducing agent such as aluminum lithium hydride, followed by acid catalyzed dehydration:
RCH=CH2 - ~ RCHOHCH20H
Any nucleophilic derivative of the above 25 substituents can be used to add these groups at the ~2Z383~
~(~
t)eta ~o~ition. For example, RCHOHCH20H + NaNH2 = RCHNH2CH20H + RCHOHCH2NH2 sodamide major product Addition of potassium permanganate ( ~MnO4 ) in aqueous solution will oxidize the primary alcohol back 10 to a carboxyl function:
RCHXCH2OH - ~ RCHCO0H
KMnO4 lS Where beta-halogens are involved, care must be taken to prevent an excess of acid to develop in solution, which could result in an elimination reaction, reforming the terminal alkene.
Amine derivatives would react similarly:
RCHNH2CH2OH ~ RCHNH2COOH
KMnO4 ~223833 2~
Tests using oleic acid have proved the validity of the proposed process. This material has the advan~age o being inexpensive and readily available. The 5 oleates formed during saponification are stable, nontoxic, and easily handled and transported.
Un.saturatiorl at ~ 9 could decrease the stability of this mo1ccule, especially during pressuriYed treatment with carbonic acid. The result could be addition to 1() either C9 or ClO of an alcohol moiety, or cleavage at C9 forming octanoic acid and octanedioic acid (both of which are also good extractants). Saturated fatty acids greater than four carbons in length can also be used, and may endure more cycles through the process 15 than unsaturated homologues.
Substitution of the fatty acid may be helpful in weakening its acidic carboxyl function, if the substitution is carried out adjacent to or within 5 to 2U l~ carbon lengths of the terminal carboxy moiety.
With a weakened fatty acid, i.e., one to which an a~id proton will bind more rigorously, recovery of ~he fatty acid from an aqueous solution o~ its conjugate base will require less concentra~e(l solutions of ~5 lowry-l~ronsted acids. In the case of the carl)on ~ZX~333 dioxide-carbonic acid system, this would reduce the pressure of carbon dioxide needed to bring about conversion in a given time interval.
Substitutents capable of exerting an effect on the acidity of a fatty acid as described above must be of the electron donating or "soft" type. Examples are:
Alkyl side chains; branched and straight chain;
Nitroso;
Nitrate;
Carbonate;
Aryl;
Benzyl;
Primary or Secondary Alkynyl;
Primary Alkenyl;
Sulfites;
Sulfates;
Phosphates, Phosphites;
Pyrophosphates;
Thiosulfates;
Nitriles;
Aldehydes; and, Esters.
i ,1 ~ ~23~333 In addition to making the fatty acid much easier to desaponify, these substituents, when attached at the aforementioned positions, will cause initial S removal of the acid proton co become more difficult.
If a strong base, such as sodium hydroxide or potassium hydroxide, is used in the saponification procedure, then the effect should not hinder the process.
A second group of fatty acid substitucnts may be introduced to increase the acidity of the carboxyl ¦hydrogen, and hence, allow the use of weaker, less expensive bases for saponification separation. Such 15 substituents would be of the electron withdrawing or "electronegative" variety, and, as with the soft functions, must be attached within 5 to lO carbons of the primary carboxyl moiety, and preferably adjacen~
to it. They act to lessen the electron density of ~() basic oxygen, and therefore relax the powerful bond between this oxygen and its acidic proton. The result is a stronger acid, which will undergo saponificatio more readily than an unsubstituted homologue.
¦Examples of substituents capable of increasing the ¦~5 acid strength of a fatty acid include halogens and llamines (-NH2, NRH,-NR2);-SH;-OR;-OH;-NHCOCH3;-CC13.
~223~3~13 2~
Addition of the correct substitucnt coul~ al~OW
use o Ca] cium Carbonate or lime (tlle world's L~ast expensive base) to achieve saponification, further 5 reducing long term operating costs.
The saponification step preferably includes the use of a low cost base, such as calcium oxide (lime), potassium hydroxide, or sodium hydroxide. Ral)id 10 saponification of unsubstituted, mono substituted atty aci-l derivatives of the type previously specified occurs when treated with a "strong" base such as sodium and/or potassium hydroxides; ammonia or alkoxide, salts; hydrides; and soluble suphides.
15 Stoichiometric considerations during saponification are critical. The amount of fatty acid contained in the extracted sample of petroleum must be known with substantial precision to ensure that the proper amount of base is added. If excess base in inadver~antly 20 added, quantities of untreated fatty acid will bc retained in the oil as a contaminant.
With regard to saponification unsubstitued fa~l:v acids such as 18:1~ 9 require the use of fairly 25 powerful nucleophilic bases in order for ~ 2Z~333 saponification to occur spontaneously. Such bases inclu~e:
Sodium Hydroxi(le;
Potassium Hydroxide;
Ammonia (anhydrous or in concentrated aqueous solution);
Sodium or potassium methoxide (or any salt containing methoxide);
~ Sodium, potassium ethoxide (or any salt containing ethoxide);
Group ]a Hydrides;
Tertiary Amines; (NR3) Secondary Amines; (HR2H) Primary Amines; (NH2R)2 Sodium Amide;
Potassium Amide;
Hyd r a~ine; and, Piper:idine.
~() Substitution of more electronegative functions in the vicini~y of the alpha carbon a]low use of ~he following bases:
Calcium Carbonate; Sodium Carbonate;
Sodium Bicarbonate; and, Calcium Oxide (lime).
1 2Z3~333 It has beel- demonstrated that the addition of small amounts of heat quickens the penetration of fatty acid into the pctroleum. For application to S existing wells, this poses no problem, since formation temperatures are usually quite high.
When free petroleum is presented for extraction, however, heat must be added to bring the temperature 10 to between 30 and 100 degrees C. The amount of heat needed is small enough to economically be created by burning small quantities of extracted petroleum. At this stage, no pressurization is required. Carbonic acid is a preferred saponification reagent. An 15 important limitation arises concerning the physical chemistry of carbon dioxide. At certain temperatures and pressures this 8as liquifies and no further compression can be accomplished. As reactor temperature increases, the "critical pressure", which ~0 represents the maximum allowable pressure, is pushed upward. However, it is important to keep in mind that as one increases the temperature the maximum allowable pressure increases, but the solubility of carbonic acid could decrease. As is seen from studying the 25 equation which describes solubility, it is the ratio ~223833 of pressure to temperature which actually determines the amount of carbonic acid generated in aqueous solution. As can be seen from the following table, 5 any combination of temperature and pressure conditions below or on the li.quid-vapor equilibrium line alld solid vapor line as seen on a plot of the following table can be used in the process described herein.
Log Pat atmTemp C Temp X P/T(atm K 1) 1.80 63.125 298 0.21 2.00 100.050 323 0.31 2.15 141.375 348 0.41 152.30 199.5100 373 0.53 2.40 251.2125 398 0.63 2.50 316.2150 423 0.75 2.55 354.8175 448 0.79 2.~0 398.1200 473 0.84 202.75 562.3225 498 1.13 2.80 631.0250 523 1.21 2.90 794.3275 548 1.45 2.95 891.3300 573 1.56 Desaponification occurs within vessel 42 when the ~223833 aqueous soap solution arriving from conduit 40 is subjected to acid and water therewithin. Hydronium ions will be formed.
Protonated solvent molecules will react with the soap to reconstitute the original fatty acid.
(i) GH + H2(l) G(aq) 3 (aq) ( ) 3 (aq) ,(aq) (1) (aq) 2 Above, GH represents a gas or other reagent which will, react with a solvent, in a prescribed manner to yield a hydrated proton, which, in turn, reacts with the aqueous salt, liberating a free fatty acid.
The driving force of equation (ii) is an equilibrium being made continually favourable to the right by the dissolution of fatty acids. Substances capable of acting as GH reagents include:
hydrohalic acids; hydrocyanic acids; hydrogen peroxide (may produce destructive radicals); nitric acid; nitrous acid; sulfuric acid;
sulfurous acid; phosphoric acid, phosphorous acid; acetic acid;
formic acid; propionic acid~ butyric acid; carbon dioxide; chlorous acid; chloric acid; hypochlorous acid; perchloric acid;
~2;~ 33 2~
I'erchlorous Acid; ()ther Stron~ Oxy Aci(ls;
Pic~ic Aci~; and, Ammonium compounds of the formula ( (NH4)nX-n ).
s Although the cited chemicals include large families of reagents, carbon dioxide may be the least expensive to use on an industrial scale. Its reaction l~ with water yields carbonic acid:
C02( ) ~ H2(l) = H2C03( ) ; k=2.6 X 10-3 lS Carbonic Acid will then react with water to produce the hydrated proton: (k= 4.3 X 10-7) H2C03 + H20 = HC03 H30 (aq) (1) (aq) (aq) This will react with the soap according to the 20 reverse saponification relation. The concentration of carbcnic acid depends upon the pressure of carbon dioxide (at constant temperature).
~ H 2C0 3 ) = ~_) f H CO
) Wher~ ( ) repres~nls concen~ratioll in.noles ~r liter,fH2C~ is the equilibrium formatioll const~nt ol carbonic acid from carbon dioxide and liqu:id water, S i5 the perfect gas constant, T is the absolute temperature, and PC02 is the partial pressure of carbon dioxide in units which agree with R.
The above equation is valid and applies to all conditions at which carbon dioxide is in the vapour 1~ pllase. Note that carbon dioxide may be added to the process in the liquid, or solid phase, or in any manner, including dissolving the gas in rnetals or other materials, which will produce the dissolved gas in aqueous solution, thereby generating carbonic acid.
Species which directly generate a proton by dissociation are added as the pure gas, liquid, or dissolved in aqueous or nonaqueous solution. rheir reaction would be more direct. For example, hydrohalic acids react in two steps as follows:
(aq) H2(l) = H30 (aq) + X~( (aq) + H30 (aq) = RCOOH(l) + Na+
After all chemical reactions have taken place, the excess proton yielding material is drained off to be used again, and ~he solution which now con~ains water, ~223~333 e]ectrolytes, traces of unreacted soap, and free fatty acid, is passe~ through a phase scparating dcvice, allowing the fatty acid to be collected, ~)ut r) permitting the aqueous phase to flow through. The fatty acid is then recycled back to the oil field, in thc case of reservoir apylications, or back to the inltial treatment tank in the case of mined or drilled tar sands.
1~
EXAMPI,E I:
With reference now to Figure 2 of the drawings, petroleum oleic acid mixtures enter the process lOA
15 from pipe 80 and are combined with water from pipe 82 in settling tank 84. Agitation device 86 is thell engaged, along with heating element 88. Any contaminating particles from the petroleum will be removed. Agitator 86 is then disengaged, allowing ~0 contaminants to settle to the bottom of vessel 84, being outputted through valved line 80. Mined oil sands can be directly added to vessel 84 after the majority of sediments have been separated. Pump 92 moves the biphasic mixture to phase separator 94.
~5 Water is then removed through pipe 99 to be recyc~ed back to tank 84.
~ZZ3833 Petrol~um and oleic acids flow through pipe 100 into saponification tank 102. A strong base, iOe., KOH
or NaOH is injected via line 103. The mixture 104 is 5 gently agitated by conventional stirrer apparatus 108 for a few minutes. Because this process is highly exothermic, some of the heat may be collected and returned to tank 84, i.e. tanks 102 and 84 should be mechanically disposed in heat exchange relation.
The saponified mixture is then moved to separator 111 in which it is pas~ed over a teflon grid. The petroleum will stick and is collected through line 112 and valve 113. The saponified fatty acid flows over 15 and through this grid, out pipe 116 and into pressure vessel 118 with pinvalve 122 open. Tank 118 must be constructed of molybdenum steel or some other alloy able to withstand internal pressures in excess of 1000 atmospheres.
Carbon dioxide is added through pipe 120 from source 123 at the desired pressure. Heat may then be added through coils 124 (or may be exchanged from tank 102). After a few minutes, valve 122 is opened, releasing the pressure inside tank 118. This is ~2Z3B33 carbon clioxide gas, and can be collected for reuse? or released.
Inside phase separator 130 oleic acids are sel)arated from the remaining aqueous solution over a teflon grid in separator 111~ The a~ueous layer is removed through ~ipe 133 and may be recycled to tank 84. The olcic acid flows through return pipe 140 ]0 Drum drying at 142 may be required before it is sen~
back to the well site via return line 144.
EXAMPLE II:
Figure 3 represents a refinement of the same process illustrated in Figure 2 with an emphasis on enery conservation.
Raw petroleum-oleic acid mixtures enter through 2() pipe 150 to settling tank 152. Water is addcd through pipe 154. The mixture is then agita~ed by ro~or 156.
~leat may be added through coil 158. Af~er a few minutes, agitation is stopped, and the phases are allowed to separate. At this point, all sedimentary 25 contaminants will have settled to the bottom of tank 152 and may be disposed through cleaning port 160.
:1223B33 lluid pump 164 then moves the combined phases into yhase separator 166. Water is removed through pipe 168 to be reused in tank 152, Petroleum and oleic acids 5 travel through pipe 170 into tank 172 which is constructed so as to surround tank ]76.
An alkaline base is added through pipe 179 and gentle agitation is produced by apparatus 180.
10 Sufficient heat should be generated to speed the process in tank 176.
~ fter a few minutes, the contents of tank 172 are transferred via line 184 to phase separator 186, a 15 teflon grid separator. Petroleum is removed to the refinery through pipe 180.
The oleic acid flows through valve 195 into tank 176 with release valve 197 open. Carbon dioxide from 2~ a reservoir at the end of pipe 200 flows into tank 176. When the desired pressure has been established, valve 202 is closed and the mixture is allowe~ to react for several minutes. Small heat exchange fins may be attached to tank 176 such that they protru(le 25 into tank 172 to promote heat exchange. As before, tank 176 must be constructed so as to contain pressures at least as large as 1000 atmospheres.
When valve 209 is opened, pressures inside will force the contents of tank 176 into phase separator 212. The excess carbon dioxide can be recovered or released.
Separator 212 is designed such that the aqueous phase may be collected through valve 213 while the fatty acid is recovered through valve 215 to be recycled back to the petroleum well site.
EXAMPLE III
The fatty acid is added to petroleum or oil sands in an amount which will sufficiently reduce the viSC08ity S0 as to simplify recovery. The amount 20 added must be recorded with precision, since the following saponification step requires adherence to a stoichiometric relation:
R - C - OH + KOH = R - C - OK + H20 O O
. ~
~22~833 In this instance, the stoichiometric coefficients are unity for all involved species. The same is trué
of sodiurn hydroxide or ammonia when used as S saponifying agents:
R - ICI - OH + NaOH = R - C - ONa = HzO
o Il NH3 R ICI ONH4 O O
If a chlorinated fatty acid is used for viscosity 1(~ reduction, less expensive bases, such as lime (calcium oxide) may be used:
2R-C- C - OH + CaO = (R-C-C-O-)2Ca + H2O
Cl O Cl O
Although calcium soaps are generally not very water soluble, addition of the halogen moieties near the alpha terminus tend to reverse this because of their effect of changing the electronic distribution, and therefore, adding to the yolarity of the molecule.
20 In such case, the stoichiometry demands only half as much base per equivalent weight of Latty acid. The use of sodium carbonate would also produce this same relation:
Ccl Cl 2R- - C - OH + Na2CO3 = 2R-C - C - ONa + H2O + CO2 Cl O Cl O
~23833 :3() Ihe ~hird step of tlle process uses carbonic ~ci(J
under pressure to recover the free fatty acid:
R - C - OH - CO + H O = NaHCO = R-C - OH
~ 2 2 3 ~
The stoichiometry would be the same for halogenated fatty acids.
From the foregoing, it will be seen that this 1(~ inventi,on is one well adapted to ohtai,n all the ends and objects herein set forth, together with other advantages which are obvious and which arc inherent to the structure.
It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be 25 interpreted as illustrative and not in a limiting sense.
Claims (25)
1. A method for recovering crude oil for subsequent refining, the method comprising the steps of:
(a) exposing a fatty acid to a source of raw crude oil;
(b) agitating said fatty acid with respect to or within the crude oil to produce a solvated crude oil mixture of reduced viscosity;
(c) saponifying said solvated crude oil mixture of step (b) by reacting the same with a nucleophilic base under pressure to separate the solvated crude oil mixture into petroleum crude and fatty acid soap which migrates to an aqueous phase;
(d) separating said petroleum crude from said fatty acid soap of step (c);
(e) desaponifying said fatty acid soap to recover said fatty acid for subsequent recycling and reuse in conjunction with step (a), said desaponification step including the steps of:
(i) inputting said fatty acid soap in said aqueous phase into a high pressure containment vessel;
(ii) reacting said fatty acid soap with an acid for donating a hydrated proton within said vessel to reconstitute the fatty acid used in step (a);
(iii) separating the reconstituted fatty acid of step (ii); and, (iv) recycling the recovered fatty acid of step (iii) into step (a).
(a) exposing a fatty acid to a source of raw crude oil;
(b) agitating said fatty acid with respect to or within the crude oil to produce a solvated crude oil mixture of reduced viscosity;
(c) saponifying said solvated crude oil mixture of step (b) by reacting the same with a nucleophilic base under pressure to separate the solvated crude oil mixture into petroleum crude and fatty acid soap which migrates to an aqueous phase;
(d) separating said petroleum crude from said fatty acid soap of step (c);
(e) desaponifying said fatty acid soap to recover said fatty acid for subsequent recycling and reuse in conjunction with step (a), said desaponification step including the steps of:
(i) inputting said fatty acid soap in said aqueous phase into a high pressure containment vessel;
(ii) reacting said fatty acid soap with an acid for donating a hydrated proton within said vessel to reconstitute the fatty acid used in step (a);
(iii) separating the reconstituted fatty acid of step (ii); and, (iv) recycling the recovered fatty acid of step (iii) into step (a).
2. The method as claimed in Claim 1 wherein said fatty acid is selected from the group consisting of caproic acid; caprylic acid; capric acid; lauric acid;
myristic acid; palmitic acid; stcaric acid; arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid; alkenediolic acid; alkenoic acids linoleic acid; truenoic acids and tetranoic acids.
myristic acid; palmitic acid; stcaric acid; arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid; alkenediolic acid; alkenoic acids linoleic acid; truenoic acids and tetranoic acids.
3. The method as claimed in Claim 1 wherein said acid for donating a hydrated proton employed in conjunction with desponification step (e) is capable of producing a proton in aqueous solution to precipitate said acid from a solution of its conjugate base and is selected from the group consisting of nitric acid; nitrous acid; hydraulic acids;
hydrocyanic acids; hydrogen peroxide; sulfuric or sulfurous acid; phosphoric or phosphorous acid; acetic acid; formic acid; prophoric acid; butyric acid;
carbonic acid; chloric or chlorous acid; hypochlorous acid; perchloric acid; perchlorous acid; picric acid;
an ammonium compound of the formula (NH4)nXn where n is an integer and X is an ion with a charge -n; carboxylic acid; phenol and its aryl substituted derivatives; and terminal alkynes.
hydrocyanic acids; hydrogen peroxide; sulfuric or sulfurous acid; phosphoric or phosphorous acid; acetic acid; formic acid; prophoric acid; butyric acid;
carbonic acid; chloric or chlorous acid; hypochlorous acid; perchloric acid; perchlorous acid; picric acid;
an ammonium compound of the formula (NH4)nXn where n is an integer and X is an ion with a charge -n; carboxylic acid; phenol and its aryl substituted derivatives; and terminal alkynes.
4. The method as claimed in Claim 1 wherein said nucleophilic base employed in saponification step (c) is selected from the group consisting of sodium hydroxide; potassium hydroxide; ammonium hydroxide;
potassium or sodium methoxide; potassium or sodium ethoxide; tertiary amines; primary or secondary amines; potassium or sodium amide; hydrazine; and piperidine .
potassium or sodium methoxide; potassium or sodium ethoxide; tertiary amines; primary or secondary amines; potassium or sodium amide; hydrazine; and piperidine .
5. The method as claimed in Claim 3 wherein said fatty acid is selected from the group consisting of carproic acid; caprylic acid; capric acid; lauric acid; myristic acid; palmitic acid; stearic acid;
arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid;
alkenediolic acid; alkanoic acids linoleic acid;
truenoic acids; and tetranoic acids.
arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid;
alkenediolic acid; alkanoic acids linoleic acid;
truenoic acids; and tetranoic acids.
6. The method as claimed in Claim 3 wherein said nucleophilic base employed in saponification step (c) is selected from the group consisting of sodium hydroxide; potassium hydroxide; ammonium hydroxide;
potassium or sodium methoxide; potassium or sodium ethoxide; tertiary amines; primary or secondary amines; potassium or sodium amide; hydrazine; and piperdine.
potassium or sodium methoxide; potassium or sodium ethoxide; tertiary amines; primary or secondary amines; potassium or sodium amide; hydrazine; and piperdine.
7. The method as claimed in Claim 6 wherein said fatty acid is selected from the group consisting of caproic acid; carylic acid; capric acid; lauric acid;
myristic acid; palmitic acid; stearic acid; arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid; alkenediolic acid; alkenoic acids; linoleic acid; truenoic acids and tetranoic acids.
myristic acid; palmitic acid; stearic acid; arachidic acid; behinic acid; lignoceric acid; mono and/or poly alkanoic acid; hydroxyalkanoic acid; alkenediolic acid; alkenoic acids; linoleic acid; truenoic acids and tetranoic acids.
8. The method as claimed in Claim 2 where said last mentioned group includes acid derivatives thereof.
9. The method as claimed in Claim 7 where said last mentioned group includes acid derivatives thereof.
10. The method as claimed in Claim 8 wherein said nucleophilic base is further selected from tile group consisting of calcium carbonate, sodium carbonate, sodium bicarbonate, and calcium oxide.
11. The method as claimed in Claim 7 including the step of settling said solvated crude oil mixture of reduced viscosity after agitating step (b) but prior to saponifying step (c) to remove abrasive non-reactive particles therefrom.
12. The method as claimed in Claim 11 wherein separating step (iii) includes the step of precipitating salts from the resulting solution of step (ii).
13. The method as claimed in Claim 1 wherein saponifying step (c) comprises the step of pressurizing said solvated crude oil mixture and water within a pressure vessel in the presence of carbon dioxide gas to generate carbonic acid.
14. The method as claimed in Claim 13 wherein said pressurizing step is conducted between 50 and 100 atmospheres, and a temperature between 10 and 200 degrees centigrade.
15.The method as claimed in Claim 2 wherein said alkanoic acids are selected from the group consisting of oleic acid, petroselaidic acid and octadecenoic acid.
16. The method as claimed in Claim 2 wherein said truenoic acids are selected from the group consisting of alpha linoleic acid and gamma - linoleic acid.
17. The method as claimed in Claim 2 wherein said tetranoic acids include aracadonic acid.
18. The method as claimed in Claim 5 wherein said alkanoic acids are selected from the group consisting of oleic acid, petroselaidic acid and octadecenoic acid.
19. The method as claimed in Claim 5 wherein said truenoic acids are selected from the group consisting of alpha - linoleic acid and gamma - linoleic acid.
20. The method as claimed in Claim 5 wherein said tetranoic acids include aracodonic acid.
21. The method as claimed in Claim 7 wherein said alkanoic acids are selected from the group consisting of oleic acid, petroselaidic acid and octadeccnoic acid.
22. The method as claimed in Claim 7 wherein said truenoic acids are selected from the group consisting of alpha - linoleic acid and gamma - linoleic acid.
23. The method as claimed in Claim 7 wherein said tetranoic acids include aracadonic acid.
24. The method as claimed in Claim 11 wherein said non-reactive particles are sand.
25. The method as claimed in Claim 1 wherein said raw crude oil is selected from the group consisting of subterranean petroleum reserves, tar sands deposits, kerogen and oil shale.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000466334A CA1223833A (en) | 1984-10-25 | 1984-10-25 | Recycled fatty acid crude petroleum recovery system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000466334A CA1223833A (en) | 1984-10-25 | 1984-10-25 | Recycled fatty acid crude petroleum recovery system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1223833A true CA1223833A (en) | 1987-07-07 |
Family
ID=4129006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000466334A Expired CA1223833A (en) | 1984-10-25 | 1984-10-25 | Recycled fatty acid crude petroleum recovery system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1223833A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116556909A (en) * | 2023-04-19 | 2023-08-08 | 中国石油天然气股份有限公司 | Device and method for efficient separation and cyclic reinjection utilization of carbon dioxide flooding |
-
1984
- 1984-10-25 CA CA000466334A patent/CA1223833A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116556909A (en) * | 2023-04-19 | 2023-08-08 | 中国石油天然气股份有限公司 | Device and method for efficient separation and cyclic reinjection utilization of carbon dioxide flooding |
| CN116556909B (en) * | 2023-04-19 | 2024-05-28 | 中国石油天然气股份有限公司 | Device and method for efficient separation and cyclic reinjection utilization of carbon dioxide flooding |
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