MX2010007010A - Method for production of short chain carboxylic acids and esters from biomass and product of same. - Google Patents

Abstract

A method for producing a mixture of short chain carboxylic acids (28) from biomass (10) includes adding biomass (10) to a reactor vessel, heating the biomass to crack it, removing undesired (20) and unreacted (18) materials and light ends (16) from the cracked biomass, and removing a mixture containing carboxylic acids having carbon chain lengths between C2 and Cl 6 (24). A composition includes a carboxyl group- containing compound (28) derived by cracking biomass (10) and having a carboxyl carbon chain length between C2 and C 16.

Description

METHOD OF PRODUCTION OF CARBOXYLIC ACIDS AND STERES OF CHAIN SHORT FROM BIOMASS AND PRODUCT OF THE SAME Background of the Invention One of the key challenges facing the modern industrialized society is the rapid depletion of crude oil, which is the primary source for most transportation fuels and many organic chemicals. The petrochemical industry represents a substantial benefit for a human society and the invention and commercialization of alternative sources for petrochemical substances is of great importance.

Two categories of organic chemicals that are frequently produced from petroleum are short chain carboxylic acids and short chain carboxylic esters. These chemicals have a wide range of uses, including serving as monomers for many types of polymers, paints, coatings, and fragrance sources for perfumes and other useful substances.

The use of short chain carboxylic acids as monomers is of particular importance. Substantial efforts have been made in recent years to develop usable polymers from the fatty acids bound within the triglycerides. Processes such as Soyol processes incorporate fatty acids from Ref. : 211898 triacylglycerides directly in the polymers. A disadvantage of these processes is that the resulting polymers have properties that are different, and in many cases inferior, to the existing polymers produced from monomers based on petrochemical substances.

Surprisingly, very little work has been done to chemically modify the triacylglycerides to produce monomers based on useful fatty acids and other useful chemicals which are identical, or almost identical, to the existing monomers. Accordingly, there is a need to provide an alternative source for these chemicals so that the demand that can be satisfied as a source material, crude oil, is reduced.

Brief Description of the Invention The invention described herein provides a process for the production of short chain carboxylic acids and short chain carboxylic esters, of commercial grade, from triacylglycerides, long chain fatty acids, long chain lipids, or similar chemical substances.

One embodiment of the present invention is a method for producing a mixture of short chain carboxylic acids from biomass. The method includes adding biomass to a reaction vessel, heating the biomass to fragment it, removing undesirable materials and not Reacted, and light ends of the fractionated biomass, and remove a mixture containing carboxylic acids having carbon chain lengths between C2 and C16.

Another embodiment of the present invention is a composition that includes a compound containing a carboxyl group derived by fragmenting the biomass and having a length of the carbon chain of the carboxyl between C2 and C16.

In a first aspect of the invention, an oil containing mainly fatty acids intercalated within the triacylglycerides obtained from the plants, expressed from algae, derived from the biomass of animals, or derived from other sources, is added to a container of reaction.

In a second aspect of the invention, the oil is heated in the reaction vessel to a temperature of from about 100 ° C to about 600 ° C at a pressure ranging from about vacuum conditions to about 211.11 kg / cm2 abs. (3000 psia) for a sufficient time to break the oil. During the process, the undesirable material, the oil that did not react, and the light ends are removed from the fragmented oil. The purified material contains chemical compounds that are desirable for isolation as acids short chain carboxylic and fuel.

In a third aspect of the invention, the short chain carboxylic acid compounds are extracted from the fuel compounds and purified. The short chain carboxylic acids generally include fatty acids with 2-12 carbon atoms (C2-C12). Desirable fuel components generally include C4-C16 alkanes, alkenes, aromatics, cycloparaffins, and alcohols.

In a fourth aspect of the invention, the preferred extraction of the selected fatty acids is carried out by the liquid-liquid extraction using a basic aqueous solvent such as an amine similar to a trimethylamine. The solvent rich in fatty acids is regenerated to release the fatty acids from the solvent. The individual C2-C12 fatty acids are obtained in the purified form by physical and / or chemical separation.

In a fifth aspect of the invention, the preferred extraction of the selected fatty acids is carried out by a consecutive liquid-liquid extraction method whereby the water at room temperature is used to preferentially extract the C2-C5 fatty acids , then the water at higher temperature or a basic aqueous solution is used to selectively extract the C4-C7 fatty acids, and finally pressurized hot water or other solvent it is used to preferentially extract the C6-C12 fatty acids. After extraction, the individual C2-C12 fatty acids are obtained in the purified form by physical and / or chemical separation.

In a sixth aspect of the invention, the esterification of one or more of the individual C2-C12 short chain fatty acids or a mixture thereof using an alcohol or a mixture of alcohols, is carried out. The esterification of the alcohols employed for the esterification include, but are not limited to, methanol, ethanol, normal propanol, iso-propanol, normal butanol, iso-butanol, allyl alcohol and other alcohols. After esterification, the esterified material is separated from the material that did not react.

Brief Description of the Figures Figure 1 is a simplified block diagram illustrating one embodiment of a short chain carboxylic acid production process.

Figure 2 is a simplified block diagram illustrating one embodiment of a short chain carboxylic acid extraction process.

Figure 3 is a simplified block diagram illustrating one embodiment of the short chain carboxylic acid purification process.

Figure 4 is a graph illustrating the extraction of fatty acid with trimethylamine.

Figure 5 illustrates a simulation model of ASPEN Plus for a series of distillation columns for separating and purifying the short chain carboxylic acids.

Detailed description of the invention To more accurately describe the invention, the following terms are defined to have the following associated meanings: "Biofuel" means any fuel that is derived from the biomass of a plant or an animal.

"Biomass" means any non-fossilized, organic material that is derived from the mass of any biological organism excluding mass that has been transformed by geological processes into substances such as vegetable charcoal or petroleum.

"Biomass oil" means any oil derived from a source of biomass.

"Carboxyl group" means a portion of a chemical molecule that contains a carbon atom with a double bond connection to an oxygen atom and wherein the same carbon atom is also connected to a hydroxyl group, and where no other atom is connected by a chemical bond to a doubly bonded oxygen atom. This structure is acidic because in certain solutions, the hydrogen atom on the hydroxyl group dissociates easily from the chemical molecule, forming a cation (the hydrogen atom) and an anion (the rest of the chemical molecule).

"Catalyst" means that substance that accelerates the speed or ease of a chemical reaction.

"Catalytic fractionation" means a fractionation process using a catalyst.

"Fractionation" means any process that changes the chemical composition of a chemical substance or mixtures of organic chemical substances by the segmentation of one or more carbon-carbon bonds in one or more molecules.

"Crop" means any plant.

"Diesel" means a commercially made fuel for diesel-powered vehicles.

"Ester of carboxylic acid" is a chemical compound formed by the reaction of a carboxylic acid and an alcohol, wherein a terminal hydrogen atom of the carboxyl group is replaced by a carbon chain (radical) of the alcohol.

"Fatty acid" means a carboxylic acid with a saturated or unsaturated aliphatic rear end element.

"Hydroxy group" means a portion of a chemical molecule that contains a connected oxygen atom by a simple bond to a hydrogen atom and also connected by a simple bond to the rest of the chemical molecule, where the hydrogen atom is not connected to any other atoms.

"Light ends" means chemical substances that remain in the gas phase at temperature and pressure conditions in which the intermediate distillates are in the liquid phase.

"Intermediate distillation" means a chemical substance having properties capable of inclusion in a gasoline, kerosene, or diesel type fuel or having a volatility similar to those of paraffins and / or olefins that are capable of inclusion in a gasoline , kerosene, or fuel of the diesel type. An intermediate distillate may also contain carboxylic acids.

"Plant" means any living organism that is a member of the Plantae kingdom or of the Chiorphyta division (green alga).

"Vegetable oil" means lipids that are derived from plant sources. Examples of vegetable oils include crop oils or vegetable oils and oily seeds.

"Short chain carboxylic acid" means a chemical compound with not more than 12 carbons containing a carboxyl group.

"Short chain carboxylic ester" means a chemical compound derived from a short chain carboxylic acid in which the carboxylic acid group is replaced by an ester group.

"Alquitranes" are very long chain chemical compounds, generated during the fractionation reaction.

"Thermal fractionation" means a fractionation process that involves the addition of energy in the form of thermal energy as measured by an increase in the temperature of the substance that is fractionated.

"Triacylglyceride" or "TG" is a major component of unmodified vegetable oils, is an ester of glycerol and three fatty acids.

"Raw material that did not react" is the material in the product stream of the fractionation reactor that has a chemical composition that is not capable of acting as a component of the intermediate distillate mixture and can also be exposed to the reactor conditions of fractionation and transformed into an intermediate distillate and / or light ends and / or tars. These compounds can be chemically identical to the original raw material, a fatty acid whose length is identical or similar to the chains of fatty acids on a original triacylglyceride (when the triacylglycerides are in the feed) or a partially fractionated paraffin, olefin or carboxylic acid, which has too many carbon atoms in the primary carbon chain to be able to function as a component of a mixture of the intermediate distillate.

No previous invention or published work has been identified which describes the use of thermal and catalytic fractionation for the formation of carboxylic acids and / or short chain esters. Accordingly, there is a need to develop a method that allows an oil from a culture, a biologically generated lipid, or an animal fat oil raw material to be converted into these important and valuable chemical substances. The present invention uses separation technologies coupled with thermal / catalytic fractionation techniques to develop chemical substances based on an oil from a culture, a biologically generated lipid, or an animal fat, which can replace the chemical substances available generated from other sources of raw materials.

The present invention is directed to the production and purification of short chain carboxylic acids from C2 to C16 with a potentially subsequent conversion to the short chain carboxylic esters from vegetable oils, biologically generated lipids, or animal fats. Specifically, the raw materials are triacylglyceride compounds. This invention provides a means to produce these valuable and necessary chemical substances from new raw materials, not currently used in their production. Chemical modifications, based on the use of fractionation and separation techniques, are designed to produce commercial grade short chain carboxylic acid chemicals, which can directly replace comparable chemical products generated from other sources of raw materials.

The search that explores the thermal and catalytic fragmentation of triacylglycerides (individual triacylglycerides and vegetable oils) has occurred sporadically in recent decades. From these works, a set of organic reactions that occur during the thermal / catalytic fractionation of triacylglycerides have been identified. These reactions are illustrated in Table 1, which is given below.

Table 1 2. De-ketenization (continuation of the reaction la) 0¾ (0¾) eCH2-CH rCHj (CHs), (ketene) of the a la rreeaacccciión the) 5. Fractionation of unsaturated hydrocarbons (shown for the position of the predominant atyl) CHjlCH ^ nCHj-CHj- CMsíCHánCH-CH, Formation of branched radicals Ffc-O + CHj-CHa * | ~ C-CH3 -CH * - Dehydration and hydrogenated The chemical composition of the generated fractional material, typically obtained from fresh or used vegetable oil, was reported in a number of studies. The known total process routes are placed as diagrams later in table 2.

Table 2 where to the route 1 is the catalytic fractionation at low temperature: Alencar, 1983; at 300 ° C; b route 2 is catalytic fractionation at high temperature: Katikaneni, 1995; at 450 ° C; c route 3 is non-catalytic fractionation at low temperature: Schwab, 1988; at 300-360 ° C; * An additional 9.7-10.1% is listed as "unsolved unsaturated substances".

Surprisingly, conditions were discovered that allow the generation of commercially viable concentrations of short chain carboxylic acids. When purified to remove the light ends, the heavy ends, and the unreacted material, the resulting intermediate distillate contains 5% or more of short chain carboxylic acids, preferably 20% or more of short chain carboxylic acids, more preferably 30% or more of short chain carboxylic acids, and still more preferably 60% or more of short chain carboxylic acids. The present invention utilizes thermal or catalytic fractionation technologies known in the art, coupled with separation technologies such as distillation, filtration, solvent extraction, and related technologies, for the specific purpose of producing commercial grade short chain carboxylic acids from from the biomass. Previously, these same short chain carboxylic acids were produced from sources other than biomass.

It has further been discovered that there is an economic advantage to further process some or all of the purified short chain carboxylic acids or a mixture thereof to produce esters of short chain carboxylic acids. This aspect of the invention utilizes esterification reactions with one or more alcohols, these reactions are known in the art, linked with separation technologies such as distillation, filtration, solvent extraction and related technologies, for the specific purpose of producing acid esters short chain carboxylic, commercial grade, which are derived from biomass. The short chain carboxylic acid esters that can be produced by this process vary from 2 to 6 carbon atoms in length.

The raw material for this new process is any triacylglyceride, a free fatty acid or another carboxylic acid that represents a group of chemical compounds that can be found in plants or vegetable oils or intermediate chain fatty acids (C10-C14) and more long (greater than C16) that are synthesized naturally and found in biomass such as algae, animal fats, or modified materials. Triacylglycerides in vegetable oils they generally contain three fatty acids (naturally synthesized carboxylic acids) of intermediate chain (C10-C14) and / or long chain (greater than C16) connected by means of a glycerol group. These intermediate and / or long chain fatty acids can be purified, separated, and chemically modified for use as a power source or a chemical feedstock or as a potential transport fuel. Plants and vegetable oils include, but are not limited to, flax, soy, safflower, sunflower, sesame, canola, rapeseed, jatropha, evening primrose, poppy, camelina, crambe, olive, coconut, palm, cotton, corn, soybeans, Jojoba, pennycress, tomato and nuts. The compositions of some commercially available, major crop oils are listed in Table 3.

Table 3 Cultivation% polyinsa-% saturated% mono Name% lí- 18: 3 18: 2 22: 1 18: 1 18: 0 16: 0 Total asked Corn 4 - 59 - 24 17 - 17 Crambe 26-38 5 9 55-60 17 - - 3 Linen 35 58 14 19 4 5 9 Soy 20 7 50 - 26 3 12 15 Oleic soybean 20 0.5 28 60 4 9 13 intermediates Safflower 59 - 75 - 13 12 - 12 Sunflower 47 - 74 - 23 3-4 7 10-11 Sunflower NuSun® 45-50 - 15-35 - 50-75 3-4 4-5 7-9 Sunflower raised 45-50 7 83 4 5 9 in oleic Evening Primrose 17 - 81 - 11 2 6 8 Sesame 49.1 - 45 - 42 13 - 13 Cañola 30-35 8 22 1 64 3 1 4 Colza 30-35 8 22 30-45 19 4 1 5 Olive 20 - 8 - 75 16 - 16 Coco 35 - 3 - 6 - 91 91 Palma 35 - 2 - 13 - 85 85 Camelina 31 31.2 23.1 2.8 16.8 3.0 7.8 10.8 The typical fatty acids contained in the culture oils include saturated and unsaturated fatty acids. Saturated fatty acids do not contain any double bonds or other functional groups. Unsaturated fatty acids contain two or more carbon atoms that have a carbon-carbon double bond. Saturated acids include stearic (C18; 18: 0), palmitic (C16; 16: 0), myristic (C14; 14: 0), and lauric (C12; 12: 0). Unsaturated acids include those such as linolenic (cis, cis, cis C18; 18: 3), linoleic (cis, cis, C18; 18: 2), oleic (cis 18; 18: 1), hexadecanoic (cis, cis C16: 16: 2), pamitoleic (cis C16; 16: 1), and myristoleic (cis C14); 14: 1).

It is already known that the thermal and catalytic fractionation of medium-chain (C10-C14) and / or long-chain fatty acids (naturally synthesized carboxylic acids) (greater than C16), combined with separation and purification technologies, can produce a mixture of chemical substances suitable for use as a fuel or a mixture of fuel raw materials, more specifically as components in diesel fuels, kerosene, aviation turbosine, and motor gasoline. An example of a method for deriving the fuel from the biomass is described in the U.S. patent application. Serial No. 11 / 824,644 (Seames), which is incorporated herein for reference. The U.S. patent application Serial No. 11 / 824,644 describes a process for producing a fuel from biomass with a cloud point below -10 ° C. The present invention describes a process that can produce carboxylic acids and short chain carboxylic acid esters at the same time that materials suitable for use in fuels or mixtures of fuel raw materials are also produced. The combination of a production of carboxylic acids and esters of short chain carboxylic acids with a Fuel or fuel products, offers the ability to produce not only one but two beneficial products using a set of fractioning parameters.

In the fractionation process, the energy is used to break the carbon-carbon bonds. Once it has been fragmented, each carbon atom ends with a single electron and free radicals. The reactions of free radicals can lead to several products illustrated in Table 1. The breakdown of large organic molecules into the smaller, and more useful, molecules can be achieved using high pressures and / or temperatures with a catalyst (catalytic fractionation). ) or without (thermal fractionation). Previous research has shown that medium chain (C10-C14) and long chain fatty acids (naturally synthesized) fatty acids (greater than C16) are compatible for the fractionation process, using either thermal or catalytic fractionation). These techniques have been used in previous inventions and studies to modify the chemical composition of crop seed oils or biodiesel. However, they have not been used to produce commercial grade short chain carboxylic acids and / or esters.

Figure 1 is a simplified block flow diagram of one embodiment of the production process short chain carboxylic acid. Biomass (including crop seed oils, lipids and animal fat raw materials) 10 is produced by processes now available or that may be discovered in the future. The biomass 10 can be preheated or fed directly into a fractionation reactor for the thermal fractionation stage 12. By varying the time, temperature, and pressure under which a particular raw material remains under fractionation conditions, the desired degree of fractionation (conversion) can be controlled. Temperature and time (residence time) are the most important process variables with a pressure that plays a secondary role. The products of the fragmentation process depend on the fractionation conditions and the original composition of the biomass 10 and the gaseous environment present in the fractionation reactor. In general, biomass 10 is heated to a temperature ranging from 100 ° C to 600 ° C at pressures ranging from vacuum conditions to 211.11 kg / cm2 abs. (3000 psia) in the fractionation reactor for residence times ranging from 1 to 180 minutes. The temperature range is more preferably from 300 ° C to 500 ° C and even more preferably from 390 ° C to 440 ° C. The fractionation conditions are varied based on the analyzes detailed chemicals to produce the optimal mixture of short chain carboxylic acids and fuel components.

A catalyst can be used to improve the performance of desirable products, to reduce the formation of undesirable products, or to increase the efficiency of the fractionation reaction due to lower pressure, temperature, or residence time requirements. The catalysts include but are not limited to zeolites, carbon and rare metals such as palladium, niobium, molybdenum, platinum, titanium, aluminum, cobalt, gold and mixtures thereof.

The fractionation output is subjected to a variety of processing and purification steps 14 depending on the material generated. The output of the drive reactor depends on the specific reactor design used. The following are examples of reactor types known to those skilled in the art: batch, continuous flow through, flow through a packed bed, and fluidized bed. The material generated in the fractionation reactor can generally be defined as light vapors 16, unreacted (recyclable) raw materials 18, waste materials or residues (tars) 20, and an intermediate distillate 22.

The light ends 16 are materials in phase of steam that did not react, which were added to the reactor to manipulate the fractionation reaction, such as hydrogen, nitrogen, or water vapor, in addition to the small molecular weight organic chemicals and the hydrocarbons generated in the fractionation reactor. Small molecular weight organic chemicals and hydrocarbons, such as methane, methanol, ethane, ethanol, n-pentane, i-pentane, pentene, pentanol, n-butane, i-butane, butanol, butane, methyl ester, ester ethyl, etc., have chemical and physical properties that are undesirable (such as being too volatile) when present in substantial concentrations of the short chain carboxylic acid extracts or fuel components of the intermediate distillate. The light vapors are separated from the other material leaving the reactor by gas-liquid phase separation, distillation, condensation, or other processes in the purification step 14.

Raw materials that did not react 18 are chemicals that are introduced into the fractionation reactor but are not converted to chemical compounds with carbon chains shorter than C16. These materials have some chemical and physical properties that are undesirable in fuel products. The raw materials that did not react are separated from the intermediate distillate components by distillation or other separation techniques in the purification step 14. Unreacted or unfractionated raw materials 18 can then be returned to the fractionation reactor, fed to a second fractionation reactor or used for some other purpose .

Residual material or residual tars are chemical substances produced during fractionation reactions having a higher molecular weight, lower volatility and / or a lower heating value than what is desirable in an intermediate distillate 22. Some of the residual components 20 can be separated from intermediate distillate 22 in the company of raw materials that did not react 18 and processed with these raw materials that did not react 18. Other residual components 20, typically those of higher molecular weight, will be in the form of a solid material (at room temperature) after the fractionation reaction. These compounds are typically known as "tars". The tars may contain valuable chemical compounds, such as a fuel for boilers or other by-products which may be extracted from the waste material 20 by various process methods including extraction are solvents, distillation, etc., or may contain chemicals that can be transformed by chemical reactions in chemical compounds valuable Depending on the design of the fractionation reactor, the tars 20 may not be capable for further processing. Such tars may be oxidized, burned or otherwise removed from the drive reactor or fractionation catalysts by methods known in the art.

The components of intermediate distillate 22 are short chain carboxylic acid compounds generated in the fractionation reactor as well as those portions of the remaining material that contribute to the desirable chemical and physical properties of the fuel or storage products of the fuel mixture.

The short chain carboxylic acids 28 are removed from the intermediate distillate 22 using one or more process methods (step 24) including solvent extraction, distillation, etc. One embodiment of such a process is illustrated in Figure 2. The intermediate distillate 22 is introduced to a short chain fatty acid extraction column (SCFA) in step 30. The solvent, such as a 40% aqueous solution of triethylamine , hot water or aqueous NaOH, is supplied to the extraction column. The solvent absorbs the short chain fatty acids when they pass through the column, generating a solvent rich in SCFA while the other components (for example, the components of the biofuel 26) remain in a phase separated liquid and are removed from the column separately. The mixed short chain fatty acids 28 are separated from the solvent. The solvent can then be regenerated (step 32) and supplied back to the extraction column.

Once the short chain (fatty) carboxylic acids 28 are isolated from the intermediate distillate 22, they can be further processed and purified. The additional purification steps produce product streams containing mainly unitary components or specific groups of short chain carboxylic acids 28. One embodiment of a typical purification scheme is shown in Figure 3. Light fatty acids (C5 and shorter) and the heavy fatty acids (C6 to C16) are separated from the short chain fatty acids 28 mixed by the mixed SCFA separator 34. The separated fatty acids are then further separated using distillation columns to extract the fatty acids from the lengths of chains of particular carbons. For example, light chain, short chain fatty acids are supplied to a series of distillation columns. Acetic acid is isolated in a column of acetic acid 36, propanoic acid is isolated in a column of propanoic acid 38, butyric acid is isolated in a column of butyric acid 40 and the valeric acid is isolated in the acid column valeric 42. The less volatile (heavy) short chain fatty acids are isolated in a similar manner using the hexanoic acid column 44, the heptanoic acid column 46 and the heavy SCFA separator 48 (for fatty acids having eight or more carbon atoms on the carbon chain). The selected purification process depends on the technology used to isolate the short chain carboxylic acids 28 from the fuel components of the intermediate distillate 22.

The individual elements or mixtures of the short chain carboxylic acids 28 produced in this process can be further processed in the esters of short chain carboxylic acids by reacting the short chain carboxylic acid with one or more alcohols. The material which did not react and / or which is a by-product, is then removed from the short chain carboxylic acid esters to obtain the commercial grade short chain carboxylic acid esters.

In one embodiment of the invention, a seed oil from triacylglyceride cultures, a biologically generated lipid, an animal fatty oil or a transesterified derivative of any of these oils (biomass 10) is heated to a temperature ranging from 300 ° C. up to 500 ° C, in a fractionation reactor, at pressures ranging from vacuum conditions to 211.11 kg / cm2 abs. (3000 psia), in the presence of a gaseous environment that may contain an inert gas such as nitrogen, water vapor, hydrogen, a mixture of organic chemicals from a vapor phase or any other gaseous substance, for residence times that they vary from one to 180 minutes to affect the fractionation reactions that change the chemical composition of the contents of the fractionation reactor. The vapor left by the fractionation reactor (fractionated material) is subjected to downstream processing which may include cooling and partial condensation, vapor / liquid separation, extraction of by-product chemicals by solvent extraction or other manipulation of a chemical / physical property, on-site reaction, distillation or flash separation to produce an acceptable transport fuel, such as aviation turbine fuel or diesel fuel. The liquid and solids leaving the reactor (waste) are subjected to downstream processing which may include cooling or heating, liquid / solid separation, vapor / liquid separation, vapor / solid separation, extraction by By-product chemical substances by solvent extraction or other manipulation of a chemical / physical property to produce a by-product or fuel by-products acceptable Material that has not reacted or partially reacted 22, separated from either the fractionated material or the waste, can be recycled to the fractionation reactor, directed to additional fractionation reactors or used in other processes.

Example 1: Production of short chain fatty acids from soybean oil A continuous fractionation reactor system of two liters per hour was used as the fractionation reactor. Thermal fractionation under vacuum conditions was applied to soybean oil. The exit of the fractionation reactor (the fractionated material) was analyzed and then further processed. The light hydrocarbons were removed in a packed distillation column, and the heavier ones were removed using a second packed distillation column. This produced an intermediate distillate liquid containing a high percentage of short chain carboxylic acids. The intermediate distillate was then mixed with an equal amount of purified water, at room temperature, and the water and oil phases were then separated. This stage removed most of the C2-C4 fatty acids. The oil from this extraction was then mixed with an equal amount of 1 M NaOH in purified water and the aqueous phases of water and oil were then separated. Table 4 summarizes the results of the short-chain fatty acid extractions with water and NaOH. The amounts of short chain fatty acids (SCFA) extracted are represented by% (w / w) of the intermediate distillate 18.

Table 4 Example 2: Production of short chain acid from soybean oil using an aqueous amine As in example 1, an intermediate distillate 18 containing a high percentage of chain carboxylic acids short was produced from soybean oil. The intermediate distillate 18 was then mixed in a separatory funnel with a 25% (w / w) aqueous solution of trimethylamine at room temperature. The amount of the added aqueous amine solution was such that 0.002 moles of trimethylamine were present for each gram of intermediate distillate 18. The aqueous and organic phases were then separated and the acid number of the intermediate distillate 18 were measured according to the method ASTM D3242. Figure 4 illustrates the results of short-chain fatty acid extraction with an aqueous amine. As shown, the acid number of the intermediate distillate 18 after extraction is reduced to near zero, indicating that virtually all of the fatty acids were extruded into the aqueous phase.

Using the pooled data from these experiments, an ASPEN Plus simulation model was generated for a series of distillation columns to separate and purify the short chain carboxylic acids based on volatility. The results of the simulation are illustrated in figure 5. A mixture of fatty acids (carboxylic acids) is supplied by means of the pump P100 through the heat exchanger HX to the distillation column T100. Fatty acids that have two to five carbon atoms in the carbon chain are separated from mix and sent to the distillation column T200. The fatty acids having two or three carbon atoms are separated and sent to the T300 distillation column. The distillation column T300 separates the fatty acids from two carbons (acetic acid) from the three-carbon fatty acid (propanoic acid). Similarly, fatty acids having four to five carbon atoms are sent from the distillation column T200 to the distillation column T500. The distillation column T500 separates the four-carbon fatty acid (butyric acid) from the five-carbon fatty acid (valeric acid). In a similar way, the T800 distillation column separates the fatty acids having six or seven carbon atoms from those having eight or more. Fatty acids having six or seven carbon atoms are sent to the T900 distillation column where the six-carbon fatty acid (hexanoic acid) is separated from the seven-carbon fatty acid (heptanoic acid). The estimated yields are listed in Figure 5 for simulated purification.

The production method of the short chain carboxylic acids and esters described herein provides a useful tool for creating valuable chemical compounds from biomass instead of petroleum precursors. The method also allows the co-production of useful chemical compounds in the Fuel applications that use the same fractionation parameters. Efficiency gains are obtained because it is capable of generating two sets of useful chemical compounds using the stages that share some of the same processing conditions.

Although the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be replaced by the elements thereof without departing from the scope of the invention. In addition, many modifications can be made to adapt to a situation or material particular to the teachings of the invention without departing from the essential scope thereof. Therefore, it is proposed that the invention is not limited to the particular embodiments described, but that the invention will include all modalities that fall within the scope of the appended claims.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (22)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A method for producing a mixture of short chain carboxylic acids from biomass, characterized in that it comprises: adding biomass to the reaction vessel, heating the biomass in the reaction vessel to a temperature ranging from about 100 ° C to about 600 ° C at a pressure ranging from about vacuum conditions to about 211.11 kg / cm2 abs. for a sufficient time to fractionate the biomass; remove the undesirable material, the unreacted material, and the light vapors of the fractionated biomass; and removing a mixture containing at least about 5% of the carboxylic acids having hydrocarbon chain lengths between C2 and C16.

2. The method according to claim 1, characterized in that the removed mixture contains 20% or more of carboxylic acids.

3. The method according to claim 2, characterized in that the stirred mixture contains 30% or more of carboxylic acids.

4. The method according to claim 3 (characterized in that the removed mixture contains 60% or more of carboxylic acids.

5. The method according to claim 1, characterized in that it further comprises purifying the mixture in one or more carboxylic acids having carbon chain lengths between C2 and C16.

6. The method according to claim 5, characterized in that the purification is selected from a group consisting of solvent extraction, distillation, and combinations thereof.

7. The method according to claim 5, characterized in that the purified mixture is reacted with an alcohol to produce one or more carboxylic acid esters having carbon chain lengths between C2 and C16.

8. The method according to claim 7, characterized in that the alcohol is selected from a group consisting of methanol, ethanol, normal propanol, iso-propanol, normal butanol, iso-butanol, allyl alcohol and combinations thereof.

9. The method according to claim 1, characterized in that the biomass is selected from a group consisting of soybean oil, cañola oil, palm oil, sunflower oil, corn oil, flax oil, jatropha oil, cottonseed oil, safflower oil, crambe oil, evening primrose oil, sesame oil, rapeseed oil, olive oil, coconut oil, camelina oil, jojoba oil, pennycres oil, tomato oil and combinations thereof.

10. The method according to claim 1, characterized in that the temperature in the reaction vessel is between 300 ° C and 500 ° C.

11. The method according to claim 1, characterized in that the oil is heated in the reaction vessel for a time ranging from one minute to 180 minutes.

12. The method according to claim 1, characterized in that the heating in the reaction vessel occurs in a gaseous environment, wherein the gaseous environment includes at least one of an inert gas, nitrogen, water vapor, hydrogen, or a mixture of organic chemical substances in vapor phase.

13. The method according to claim 1, characterized in that it also comprises: add a catalyst to the reaction vessel.

14. The method according to claim 1, characterized in that the reaction vessel is of a type selected from a group consisting of: batch, continuous flow, flow through a bed packed and fluidized bed.

15. The method according to claim 1, characterized in that the mixture includes alkanes, alkenes, aromatics, cycloparaffins, or alcohols having carbon chain lengths between C4 and G12 and fatty acids having carbon chain lengths between C2 and C16.

16. The method in accordance with the claim 15, characterized in that the mixture includes alkanes, alkenes, aromatics, cycloparaffins, or alcohols having carbon chain lengths between C4 and C8 and fatty acids having carbon chain lengths between C2 and CIO.

17. The method according to claim 6, characterized in that the solvent extraction com rende: contacting the mixture with a solvent selected from a group consisting of water, a basic aqueous solution or an aqueous amine solution; remove one or more carboxylic acids and the solvent from the mixture; Y Separate one or more carboxylic acids from the solvent.

18. The method in accordance with the claim 16, characterized in that the carboxylic acids are recovered from water, the basic aqueous solution or other solvent by distillation, evaporation, perevaporation, pH adjustment, or other physical or chemical separation principle.

19. A compound containing a carboxyl group produced by the method according to claim 1, characterized in that the compound has a carbonyl carbon chain having a carbon chain length between C2 and C16.

20. The compound according to claim 19, characterized in that the compound is a carboxylic acid.

21. The compound according to claim 19, characterized in that the compound is a carboxylic acid ester, and wherein the carboxylic acid ester is formed by reacting a carboxylic acid produced by the method according to claim 1 with an alcohol.

22. A method for producing short chain carboxylic acids and a fuel composition having a low cloud point from the biomass, characterized in that it comprises: add biomass to a reaction vessel; heating the biomass in the reaction vessel at a temperature ranging from about 100 ° C to about 600 ° C at a pressure ranging from about vacuum conditions to approximately 211.11 kg / cm2 abs. for a sufficient time to fractionate the biomass; remove the undesirable material, the unreacted material, and the light ends of the fractionated biomass; collecting the fractions of the fractionated biomass including at least one of the C4 to C16 alkanes, alkenes, aromatic substances, cycloparaffins, or alcohols; C2 to C16 fatty acids; or methyl esters of C2 to C16 fatty acids; removing a mixture containing carboxylic acids having a carbon chain length between C2 and C16; Y combine the fractions collected from the fractionated biomass to produce a fuel composition that has a turbidity point of less than 10 ° C.