BRPI0702149B1 - heterogeneous catalyst and transesterification process comprising the use of heterogeneous catalyst - Google Patents

Abstract

heterogeneous catalyst and transesterification process comprising the use of heterogeneous catalyst. The present invention relates to a transesterification process employing a heterogeneous cu catalyst that can be recovered and reused in the process. This process presents simplified procedures and suitable solutions in order to obtain a final product with high purity, starting from a wide variety of raw materials with different quality grades and consequently choosing low cost raw materials, thus making the more flexible process in terms of economic viability. further, the present invention relates to biodiesel obtained by performing the above described process.

Description

Descriptive report Heterogeneous Catalyst and Transesterification Process

UNDERSTANDING THE USE OF Heterogeneous Catalysts

Field of the Invention The present invention relates to a transesterification process employing a heterogeneous Copper catalyst that can be recovered and reused in the process. This process presents simplified procedures and suitable solutions in order to obtain a high purity final product, starting from a wide variety of raw materials with different quality grades and therefore choosing low cost raw materials, thus making the more flexible process in terms of economic viability. Still, the present invention relates to Biodiesel obtained by performing the above described process.

Background of the Invention The production and use of Biodiesel in the world has been increasing dramatically due to the rise in the price of oil and the concern about its lower future availability. Biodiesel, chemically defined as long chain fatty acid alkyl esters, replaces petroleum derived diesel oil and can be used in mixtures containing different percentages, or “pure”, without requiring major changes in diesel cycle engines. These esters can be produced by a variety of methods, including esterification of free fatty acids and transesterification of vegetable oils with an alkyl alcohol such as methanol or ethanol, in the presence of catalysts which may be homogeneous or heterogeneous, which may help. to promote the complete transformation of triglycerides into monomer esters to produce Biodiesel within the minimum quality specifications compatible with the life of the engines that will use it and with international quality specifications.

According to the above mentioned biodiesel preparation processes, to produce one ton of biodiesel, one ton of vegetable oil is required, and approximately 0.12 tons of methanol or 0.15 tons of methanol are added to the product obtained. tons of ethanol and released 0.1 tons of glycerin. These volumes of alcohol are relative to the content that is incorporated into the final product, because for the reaction to proceed completely, larger and variable volumes must be used depending on the process employed, the alcohol in question and the quality of the vegetable oil used.

[005] The first patent application for the transformation of a vegetable oil into methyl or ethyl esters by catalytic transesterification reaction with methanol or ethanol for use as fuel dates from 31 August 1937. In this Belgian patent BE 422,877 Transesterification of African palm oil (dendê) with methanol or ethanol in the presence of sulfuric acid as catalyst for the production of corresponding methyl or ethyl esters has been described, with the clear objective of being used as fuel as indicated in the descriptive report and in the title. of that patent (Vegetable transformation process in vue of its use with carburants). This fuel, a substitute for petroleum diesel, could today be called “Chavanne Oil” in honor of the author of this brilliant idea that would make it possible to run the first bus with this fuel as early as 1938 on the commercial passenger line between the cities of Louvain. and Brussels, Belgium, as described along with other technical details in two articles from 1942 and 1943 (Bull. Agric. Congo Belge 33: 3-90, 1942 and Bull. Soc. Chim. 10: 52-58, 1943).

Since then, a number of innovations have been described and patented with the aim of improving the production and refining processes or offering better or alternative methods of producing these long chain fatty acid alkyl esters. and that only in the 1980s would they be called Biodiesel from a Chinese article published by Wang in 1988 (Development of Biodiesel fuel. Taiyang-neng Xuebao 9, 434-436, 1988 and Chem. Abstr. 111,26233 , 1989).

Other Chinese works from the 40s of the last century have described the production of "bio-gasoline" and "biokerosene" from vegetable oils such as Tunge and others, but through the technique of thermal or catalytic cracking. a completely different technique of transesterification, as can be seen in the articles by Chang, C.-C and Wan, S.-W. “China's engine fuels from Tung Oil”, Ind. Eng.

Chem. 39: 1543-1548 (1947). Chem. Abstr. 42: 1037h (1948) and from Cheng, F.-W. China Produces Fuels from Vegetable Oils, Chem. Metall Eng. 52:99 (1945).

[008] The rapid growth of biodiesel production around the world is also accompanied by technical difficulties due to variations in the raw materials used in each region. For most known processes today, there are limiting factors as to the total conversion of triglycerides to desired methyl or ethyl esters, which results in serious problems in the continuous large-scale purification and refining of biodiesel, requiring many unit operations and generating many effluents. The most commonly used catalysts today are alkalis such as sodium or potassium hydroxide or sodium and very rarely potassium alkoxides, but they can result in the formation of soaps, particularly preventing the use of oils with high acid content. free fatty acids as it results in greater difficulty in separating the biodiesel and glycerin phases. In addition, the use of homogeneous catalysts most often hinders or prevents their separation and recovery in their original form, while the use of heterogeneous catalysts has often been described as processes requiring longer reaction times, high pressures. and high temperatures resulting in high energy consumption and not always in high conversion ratios as would be desired to obtain an economically viable fuel of good quality, all despite the ease of recovery and reuse of these catalysts.

The applicant sets forth below the relevant prior art documents relating to the subject matter of the present invention.

The most commonly used catalysts are alkaline and homogeneous as described in US 2,271,619, US 2,360,844, US 2,383,579, US 2,383,680, US 2,383,581, US 2,383,614, US 2,383,660, US 2,383,632, US 2,383,633, US 2 , 38,596 and US 5,730,029 which describe the use of sodium methoxide as an alkaline catalyst in the transesterification of vegetable oils with an alcohol such as methanol, in addition to other catalysts such as sodium or potassium hydroxides and alkaline earth metal carbonates which are also cited. Although Chavanne's 1937 document cites the use of esters obtained as fuels, patents using alkaline catalysts highlight invented processes or other uses for the same products. In Brazil, the first patent for a transesterification process was described in 1980 by the document Pl-8007957 and uses sodium or potassium hydroxide to perform the desired transesterification in order to obtain the esters for use as fuel. Furthermore, the same document describes the extraction of vegetable oils directly from the grain using an alcohol as a solvent.

[011] Document PI0104107-0 discloses a chemical process aimed at modifying the molecular structure of vegetable oil (degummed or residual frying soybean oil) by chemical reaction with anhydrous or hydrated ethyl alcohol into ethyl esters (biodiesel) and consequently with physicochemical properties similar to conventional diesel oil. This invention involves two transesterification reactions: the first, in the presence of the metal alkoxide catalyst; and the second, in the presence of the catalyst sulfuric acid and sodium chloride.

US 4,164,506 discloses a method of producing fatty acid esters and alkyl alcohols by the two-step esterification of fatty acids with lower alcohols in amounts greater than fat solubility in the presence of an acid catalyst. . US 4,695,411 and US 4,698,186 also describe methods of producing biodiesel using two-step esterification of free fatty acids employing acid catalysts and, under very drastic conditions such as 10 to 12 hours at a temperature ranging from 100 to 120 °. C, ie in pressurized systems.

[013] The formation of biodiesel using reactions under alkaline and even acid catalysis with methanol are biphasic reactions and are known to process slowly as they occur only in the methanolic phase. The low concentration of the fatty material in methanol slows these reactions causing a delay in the onset of the reaction that accelerates as the concentration increases but decreases in sequence, tending to stop completely. In the case of transesterification, this problem tends to get worse if the content of free fatty acids is high, as they will be turned into soap forming emulsions, thus increasing the reaction time and lowering the yield. As a consequence of this, many authors have been doing work in an attempt to improve biodiesel production processes.

In an attempt to minimize solubility problems, US 6,712,867 and US 6,642,399 discuss the transesterification of triglycerides with an alcohol and base as a catalyst in a solution (single phase reaction) by the use of a co-solvent to temperature below the boiling point of the solution. The alcohol used may be methanol or ethanol or mixtures thereof. The volume of the co-solvent used allows the formation of a single reaction phase and may be selected from a group consisting of tetrahydrofuran, 1,4-dioxane, ethyl ether, diisopropyl ether and methyl, tert-butyl ether. The drawback of this technique is the need for adequate and expensive equipment and extra care to work large scale with volatile, flammable and expensive solvents.

[015] Another work that has aroused curiosity through the filed patents, involves the production of biodiesel “in situ” ie working directly with seeds or fruits, eliminating the need for extraction and refining of vegetable oil. Document US 2003/0229237 filed April 1, 2003 by Michael Haas et al. Describes the first use of flake soy (Laminas) in reaction with methanol or ethanol in the presence of sodium hydroxide as a catalyst for the production of biodiesel. Two other subsequent documents describe similar processes, the first US 2005/0020842 of Haas and Collaborators employing soybeans once again, while the second US 2005/0011112 of Carlos Khalil et al. Describe the use of castor beans and ethanol. However, the in situ method has not been applied on an industrial scale due to the lack of technical and economic viability as a consequence of the lack of adequate equipment for large scale industrial production processes and also because it requires the use of alcohol volumes and quantities. catalysts far superior to those used in conventional processes.

[016] In addition, the applicant sets out below documents describing methods of producing methyl and ethyl biodiesel by transesterification and esterification under heterogeneous catalysis.

[017] WO 2006/111997 deals with the fatty acid esterification reaction employing metallic copper as a supported catalyst in AI2O3, S1O2 or T1O2, at temperatures around 200 ° C, consequently under pressure, in addition to reducing the number. (index) of iodine through catalytic hydrogenation. Nothing about direct transesterification of triglycerides in the corresponding esters is described in this document. If it is desired to transform oils or fats into the corresponding esters, this process has the disadvantage that it requires two reaction steps, as it would first be necessary to hydrolyze the triglycerides to form free fatty acids to be esterified in a second step using the ester. copper / Al2 Os or copper / Si2 as a heterogeneous catalyst US 5,525,126 by Basu et al. discusses esterification and transesterification of oils and fats using barium and magnesium acetates as heterogeneous catalyst. The drawback of this procedure is that it is only effective when high pressures (around 500 psi) and high temperatures (around 200 ° C) are used, experimental conditions that make the esterification and transesterification process impractical and unfeasible from the outset. economic point of view to be applied in the production of biodiesel on an industrial scale.

[019] US 6,878,837 by Bournay and Collaborators of the Institut Francais du Petrole describes the production of high purity glycerine and fatty acid alkyl esters using zinc aluminate as a heterogeneous catalyst to promote the transesterification reaction between a vegetable oil or animal and methanol. This process is described as being highly sensitive to the presence of water, and the invention discusses how to remove water formed to keep the moisture below a given limit value. In addition to this limitation, the use of zinc aluminate requires the use of elevated temperature and pressure.

[020] Documents PI 0406233 and US 2006/069274 describe the use of CaO.MgO in stones as a heterogeneous catalyst for biodiesel production using vegetable oils and hydrated ethyl alcohol through a process involving triglyceride hydrolysis in a first step. followed by an esterification in a second step. The reaction takes place at 60 ° C and excess ethanol used is recovered hydrated.

[021] Another type of heterogeneous catalysis uses lipases as catalysts for the transesterification reaction between oils and methanol or other alcohols. However, reaction times are very high and in most cases the conversion does not exceed 95% as described in US 5,713,965 by Fogia et al. This does not allow biodiesel production according to international specifications.

US 7,138,536 describes a general method of using membranes for removal of solid catalysts, when the reaction is complete, in heterogeneous catalysis transesterification or esterification reactions.

[023] US 2005/0245405 describes the use of acid ion exchange resin as a heterogeneous catalyst to promote esterification of free fatty acids in biodiesel using methanol, ethanol, propanol and butanol.

WO 2005/063954 describes the use of alkyl tin oxide for transesterification and esterification of triglycerides and fatty acids respectively for biodiesel production under temperature and pressure.

[025] US 2003/0149289 describes the use of calcium carbonate and zinc carbonate for triglyceride transesterification for high temperature and pressure biodiesel production. The same document mentions the negative results with the use of sodium and potassium carbonates due to isomerization of double bonds to form double bonded esters conjugated to the carbonyl group, thus producing a product with a different structure than biodiesel that would be expected. by simple transesterification of the triglycerides without any additional structural transformation as usual in conventional methods.

[026] US 2006/0149087 reports the use of solid acid catalysts in transesterification reactions. Such catalysts are formed by combining a sulfuric group or a group VI metal component such as tungsten or molybdenum on the surface of a crystalline metal oxide. The present invention differs from this document in that the catalysts do not have such a combination of compounds.

WO 2007/059512 reports a process for obtaining transesterification from vegetable oils and / or animal fats employing an excess short chain alcohol and a catalyst in which the formed glycerin is continuously removed from the reaction medium. or in a batch to favor ester formation. Similarly to the present invention, the inventor states that heterogeneous catalysts such as transition metals, group VIB metals, group VIII metals, inorganic porous oxides such as zeolites, alkaline or alkaline earth metals and derivatives thereof may be used. especially the use of nickel iron and platinum. It is further said that alcohol should be in excess of oil, and the alcohol: oil ratio should be in the range of 3: 1 to 40: 1 [028] The present invention differs from the state of the art in that proportion used is quite different from that described. Still, nothing is said about Copper and / or Vanadium salts used as catalysts.

[029] Several of the known methods for producing methyl or ethyl biodiesel often do not promote a complete reaction, remaining reactionary intermediates such as monoglycerides and diglycerides that drastically impair the final product purification and refining steps, which makes the production process more expensive. large scale due to the increase of unitary operations and effluent treatment. Another factor concerns the use of ethanol, which in most biodiesel production processes is overused and cannot be reused due to the incorporation of water, being obtained in hydrated form when recovered, which makes another operational step necessary. for dehydration of it.

Considering that some aspects of existing biodiesel production processes still need to be improved, the present invention provides solutions for a complete transesterification reaction from vegetable oils which may have high acidity if using efficient catalysts. and of low added value, as well as the recovery of alcohol (ethanol or methanol) in anhydrous excess, suitable for reuse in a continuous process or even in batches.

[031] The fact that it is not necessary to pre-process vegetable oils to eliminate free fatty acids or other impurities is a great advantage over other state of the art techniques, since in other processes fatty acids, if present, would cause emulsion as they are made into soap.

[032] The biodiesel production process employed in this invention may be batch or continuous using a fixed bed reactor or any other type that permits catalyst retention, allowing the reaction liquid to pass through the free catalyst or adsorbed onto a support surface or solid such as S1O2 or AI2O3 and others, also enabling the use of column chromatographic reactors.

[033] The biodiesel preparation, production and treatment process of the present invention has a range of desired advantages and characteristics in a process such as this, resulting in a product of optimized quality and quantity, some of which are reported below: [034] ] The average reaction time employed in this invention when transformation is performed at normal (ambient) pressure ranges from 1 to 9 hours, which is highly satisfactory compared to prior art processes employing heterogeneous catalysts to promote complete reaction. that is, the conversion of triglycerides to the corresponding esters, as in most cases they require high pressures and high temperatures in addition to long reaction times;

[035] In addition, the alcohol (methanol, ethanol, propanol, butanol, amyl or isomers thereof) recovered in the process of the present invention, unlike other prior art processes, is anhydrous, moisture free which is detrimental in a chemical reaction. transesterification (as in PI 0406233) for the complete transformation of triglycerides into biodiesel;

[036] The step of removing alcohol (methanol, ethanol, propanol, butanol, amyl or isomers) in the present process ensures glycerin separation solely by density and polarity difference, without the need for inducing agents, not causing emulsification problems since soaps do not occur as in other prior art processes; Although in the specific case of methanol use, spontaneous separation may occur by simply decanting the mixture containing the total alcohol used. In this case, it is observed that the catalyst is completely in the glycerin phase, but it can still be recovered for continuous use or in a new reaction when it is adsorbed on Al2O3, S1O2 or other adsorbents.

[037] The biodiesel production and treatment process of the present invention, due to the factors described above and the fact that they eliminate the need for pre-treatment or refining of the vegetable oils used as raw materials, guarantee the economic viability since Refining process represents a significant percentage of the cost of vegetable oils employed in other state of the art procedures. The contribution to economic viability also involves simplifying the production and refining process presented herein, as well as the quality and quantity of the final product obtained by the present invention;

[038] The process of the present invention has significant improvements over existing processes as it utilizes low cost catalysts which can be recovered and reused for the production of esters as it does not require the use of (previously refined) neutral oils as it does not promote the saponification reaction, without the consequent formation of soaps, by allowing the easy separation of glycerine esters by gravity as a consequence of the evaporation of the alcohol employed, by allowing the subsequent reuse of these alcohols as they are anhydrously recovered, and by result in the formation of totally fatty acid-free biodiesel after separation of the glycerin phase, enabling the process. Objectives of the Invention The process of the present invention presents significant improvements over existing processes as it utilizes low cost catalysts which can be recovered and reused for the production of esters, for not requiring the use of neutral oils (previously refined), for not promoting the saponification reaction, not resulting in the formation of soaps, for allowing the easy separation of glycerine esters by gravity as a consequence of the evaporation of the employed alcohol, by allowing the reuse of these alcohols later as they are anhydrously recovered, and by resulting in the formation of totally free fatty acid biodiesel after the separation of the glycerin phase, enabling the process.

The present invention describes a transesterification process comprising the steps of: a) reacting: a glyceride rich material; - at least one C1-C5 aliphatic alcohol; at least one heterogeneous catalyst selected from the group comprising CuCl3, CuCl2 and mixture thereof. b) separating the ester and glycerin phases; The present invention may optionally contain the steps of: c.1) subjecting the separate ester from step b) to a further reaction according to step a); or c.2) washing the separated ester;

[041] In a preferred embodiment, the reaction time of step a) may range from 1 to 10 hours.

In a preferred embodiment, the reaction pressure of step a) may range from 1.0 to 10 kgf / cm2, in particular from 1.0 kgf / cm2 to 3.0 kgf / cm2.

[043] In a preferred embodiment, the reaction temperature of step a) may range from 60 ° C to 110 ° C.

In a preferred embodiment, the C1-C5 aliphatic alcohol: glyceride material ratio is in the range of 15 g C1-C5 alcohol per 1000 g glyceride material to 1000 g C1-C5 alcohol per 1000 g glyceride material.

In a preferred embodiment, the heterogeneous catalyst: glyceride material ratio is preferably in the range of from 0.1 g heterogeneous catalyst per 1000 g glyceride material to 90 g heterogeneous catalyst per 1000 g glyceride material.

In a preferred embodiment, the heterogeneous catalyst comprises adsorbing, dissecting and / or sequestering agents of inorganic compounds not exceeding a ratio of 5% w / w to the total mass of oil employed.

In a preferred embodiment, the step of separating the ester and glycerine phases comprises the use of temperatures between 50 ° C to 100 ° C. Preferably, the evaporated alcohol is condensed and reused.

[048] In a preferred embodiment of the present invention, the separate ester wash preferably comprises washing with water and then subjected to drying by heating under reduced pressure, or alternatively dry cleaning may be carried out using detergents. An additional filtration step for removing the heterogeneous catalyst is a further object of the present invention. In particular, such filtration may be carried out after step a) or after step b). It is a further object of the present invention to use the ester resulting from the above process as biofuel, in particular biodiesel.

Description of the Figures [051] Figure 1 shows the flow chart of the transesterification process adapted for biodiesel production.

Detailed Description of the Invention The examples described herein are not intended to limit the scope of the invention, but merely to exemplify a preferred embodiment of the invention. Any other similar and / or equivalent embodiment should be construed as falling within the scope of the invention.

[053] For the purposes of this invention, the following definitions will be used: Glyceride Material [054] The term "glyceride material" refers to vegetable and / or animal oils and / or fats containing triglycerides and / or diglycerides and / or monoglycerides and Glyceride materials useful for carrying out the invention include, but are not limited to soybean oil, cottonseed oil, corn oil, canola oil, macauba oil (Acrocomia aculeata and / or Acrocomia totai mart ), palm oil, peanut oil, pequi oil (Cariocar brasiliensis and / or Cariocar coriaceous), ouricuri oil (Syagrus coronata), jatropha oil (Jatropha curcas and / or Jatropha marcocarpa), other fats vegetables and / or animals, such as chicken, pork and / or beef tallow fats, including also oils and residual fat from frying, [055] In addition, the "glyceride material" may be chosen from oils, nec acids, crude, degummed, semi-refined and / or refined, providing a significant range of possibilities for carrying out this process due to its versatility as to the raw material employed.

[056] The transesterification and biodiesel production process of the present invention, due to the fact that it eliminates the need for pre-treatment or refining of vegetable oils used as raw materials, ensures economic viability, since the refining process represents a significant percentage of the cost of vegetable oils employed in other state of the art procedures. The contribution to economic viability also comes from the simplification of the production and refining process presented herein, as well as the quality and quantity of the final product obtained by the present invention.

[057] In the proposal of this invention, the presence of free fatty acids in the selected raw material does not interfere with the transesterification reaction, phase separation or biodiesel refining; Fatty acids still present in the reaction can be esterified to produce biodiesel in the same transformation step, although the reaction time should be increased.

[058] When free fatty acids are present in up to 15% transesterification occurs first and completely, and free fatty acids are completely separated in the glycerin phase.

[059] To obtain the best possible results, the moisture content of the raw material should be reduced as usual (under vacuum and temperature or by any other means available), Karl Fischer control of the moisture content of the raw material is recommended. used to obtain always reproducible results, but experiments containing up to 3,000 ppm of water have been performed with positive results. C1-C5 Aliphatic Alcohol The term "C1-C5 aliphatic alcohol" refers to short chain alcohols of up to five carbon atoms, selected from the group comprising methanol, ethanol, propanol, isopropanol, 1-butanol, 2 butanol, isobutanol, amyl and / or isomers and mixtures thereof.

[061] In addition, the alcohol used in the present process must be anhydrous as water may compromise the yield of the transesterification process.

The alcohol used in the present process may further come from the condensation of excess alcohol evaporated during the separation phase of the ester and glycerin phases.

[063] Still »alcohol (Methanol» Ethanol, Propanol, Butanol, amyl or isomers thereof) recovered in the process of the present invention, unlike other prior art processes, is anhydrous »moisture-free which is detrimental in a chemical reaction transesterification (as in the Brazilian document P10406233) ,. for the complete transformation of triglycerides into biodiesel.

[064] Thus, the recovered alcohol (methanol, ethanol, propanol »butanol» amyl or its isomers) is free of water, which allows its continuous reuse in a new chemical reaction »reducing the costs with raw materials. cousin ', allowing it to compete economically with the oil diesel.

Heterogeneous Catalyst The term "heterogeneous catalyst" refers to solid phase catalysts, in particular to copper salts such as CuCl, CuCl2 and mixture thereof.

[066] The heterogeneous catalyst used in the present process may further be derived from previous filtration steps of the same process, i.e. be recycled.

In addition, copper salts may be associated with adsorbing agents, dissecting agents and / or sequestering agents of inorganic and organic substances.

Examples of dissecting agents include, but are not limited to, Al 2 O 3. Its function, besides supporting the catalyst in the solid phase, is to adsorb water molecules that may occasionally form during the reaction stage.

Examples of sequestering / adsorbing agents of organic inorganic substances include but are not limited to Si02. In addition to supporting the catalyst in the solid phase, its function is to sequester any soluble inorganic substance, in particular soluble copper compounds, in order to prevent their escape from the solid phase, thus favoring their recycling and reuse.

In a preferred mode of the invention, the adsorbing, dissecting and / or sequestering agents of inorganic compounds do not exceed a ratio of 5% w / w to the total mass of oil employed.

Transesterification Process The transesterification process of the present invention comprises the steps of: a) reacting: - a glyceride rich material; - at least one C1-C5 aliphatic alcohol; - at least one heterogeneous catalyst; b) separating the ester and glycerin phases; The present invention may optionally contain the steps of: c.1) subjecting the separate ester from step b) to a further reaction according to step a); or c.2) washing the separated ester with water;

With respect to step a), the terms "glyceride material", "C1-C51 aliphatic alcohol" and "heterogeneous catalyst" are understood as described above. Additionally, this step must meet several criteria such as: a. 1) Reaction Time [073] The appropriate reaction time is that which allows partial or total conversion of glyceride material to esters. The reaction time is dependent on the pressure used in the reaction medium. For atmospheric pressures (1.03 Kgf / cm2) reaction time may range from 1 hour to 9 hours, depending on the desired conversion amount. a.2) Pressure [074] The pressure used in this step may range from 1.0 Kgf / cm2 to 10 Kgf / cm2, in particular from 1.0 Kgf / cm2 to 3.0 Kgf / cm2. High pressure considerably reduces reaction time. a.3) Temperature [075] The temperature used in this step may range from 60 ° C to 110 ° C, in particular the temperature is 1Q0DC. a.4) C1-C5 Aliphatic Alcohol Ratio: Glyceride Material [076] The amount of C1-C5 aliphatic alcohol used depends on the amount of glyceride material used. The C1-C5 aliphatic alcohol: glyceride material ratio is preferably in the range of 15 g C1-C5 alcohol per 1000 g glyceride material to 1000 g C1-C5 alcohol per 1000 g glyceride material.

In particular, a ratio ranging from 150 g C1-C5 alcohol per 1000 g glyceride material to 1000 g C1-C5 alcohol per 1000 g glyceride material is indicated for a material which has not previously undergone transesterification, while a ratio which ranges from 15 g alcohol G1-C5 per 1000 g glyceride material up to 100 g alcohol C1-C5 per 1000 g glyceride material is indicated for a material that has already undergone prior transesterification. a.5) Ratio of heterogeneous glyceride material catalyst [078] The amount of heterogeneous catalyst used depends on the amount of glyceride material used. The heterogeneous catalyst: glyceride material ratio is preferably in the range of 0.1 g heterogeneous catalyst per 1000 g glyceride material to 90 g heterogeneous catalyst per 1000 g glyceride material.

In particular, a ratio ranging from 1 g heterogeneous catalyst per 1000 g glyceride material to 90 g heterogeneous catalyst per 1000 g glyceride material is indicated for a material which has not undergone prior transesterification, while a ratio ranging from 0, 1 g heterogeneous catalyst per 1000 g glyceride material up to 9 g heterogeneous catalyst per 1000 g glyceride material is indicated for a material that has already undergone prior transesterification.

Additional Filtration Step The transesterification process of the present invention comprises an additional solid catalyst removal step, whereby the use of filtration, which may be associated with an adsorbing agent, ensures complete removal of the catalyst and contaminants which may have remained in the resulting product.

[081] The biodiesel production process employed in this invention can be either batch or continuous, employing a fixed bed reactor or any other type that allows catalyst retention, allowing the reaction liquid to pass through the free catalyst. or adsorbed onto a support surface or solid such as S1O2 or AI2O3 and the like, also enabling the use of column chromatographic reactors.

Phase Separation Step [082] With respect to step b) the phase separation between the ester formed and glycerin comprises the use of various techniques, which may be used together, sequentially or separately.

[083] One such technique is the use of temperatures ranging from 50 ° C to 100 ° C. These high temperature values allow evaporation of C1-C5 aliphatic alcohol that was not used in step a), but it is still necessary to be present for best results. You can also combine temperature values between 50 ° C and 100 ° C under reduced pressure to maximize alcohol evaporation.

[084] In this case, a tank made of various materials (stainless steel, carbon steel, etc.) equipped with an electric heater or coil for heating coupled to a steam generator or for heating using any other fluid may be used. allow heat transfer. This tank will be subjected to normal pressure or alternatively under reduced pressure through the use of a vacuum pump, benefiting, in addition to alcohol evaporation, the reaction time of transesterification. A coupled capacitor will also be used, using a suitable system for cooling and collecting alcohol (Methanol, Ethanol, Propanol, Butanol, Amyl or its isomers) for reuse. Alcohol should be stored in a moisture-free place for subsequent continuous or batch reuse.

[085] The alcohol removal step (Methanol, Ethanol, Propanol, Butanol, Amyl or its isomers) in the present process ensures glycerine separation solely by density and polarity difference, without the need for inducing agents, not causing emulsification problems since soaps do not occur as in other prior art processes. In the specific case of methanol use, spontaneous separation may occur by simply decanting the mixture containing the total alcohol used. In this case, it is observed that the catalyst is completely in the glycerin phase, but it is still possible to recover it for continuous use or in a new reaction when it is adsorbed on Al2O3, S1O2 or other adsorbents.

Therefore, the glycerine separation step in the present process may still occur by decantation, or may be accelerated if desired by the action of coalescence systems, centrifugation or even inducing agents. The glycerine obtained in this process carries with it any impurities and fatty acids that may be present in the reaction mixture.

In addition, because no water formation occurs during transesterification, the easy reuse of alcohol in its anhydrous form is possible (Methanol, Ethanol, Propanol, Butanol or Amyl.

Preferably ethanol or methanol), which is an important factor in reducing process costs as it is overused and needs to be recovered and reused.

[088] The use of centrifuges and inducing agents (chemical induction) to process phase separation in the process of the present invention can be used as a simple option resulting in high reaction and operational yields when considering the triglycerides of addition to the significant advantage that it is not necessary to pre-treat (neutralize or refine) vegetable oils to eliminate impurities and free fatty acids, as their presence does not influence the chemical transesterification reaction of the present process, thus obtaining a high yield.

[089] Because the medium is not alkaline, there is no soap formation, which would make it difficult to separate glycerin, as occurs when conventional alkaline catalysts are used. Thus, the free fatty acids in the present invention remain unchanged, and due to their high polarity and process conditions, are completely removed from the biodiesel phase, leaving together with glycerine in the separation stage which also occurs very easily.

[090] Therefore, the decantation separation process induced by the removal of excess alcohol (Methanol, Ethanol, Propanol, Butanol, amyl or their isomers) is of particular importance as it is combined with a total transformation of the present triglycerides. (even in the presence of free carboxylic acids), allows the separation of esters in a higher phase and glycerine / fatty acids in a lower phase, and also ensures the reuse of alcohol in the process. The separation of fatty acids from the upper phase containing the esters does not require the action of any chemical process or any additional chemical or physical operation.

[091] Following the catalyst removal steps (simple filtration or adsorption aided filtration), alcohol evaporation and glycerine separation, the next step is the removal of any formed intermediate that may be considered a contaminant such as and the case of monoglycerides and diglycerides.

In this regard, the present invention includes the process of a second transesterification, when necessary, for converting the monoglycerides and diglycerides into esters, using the same catalysts in heterogeneous phase and reusing the same alcohol as the previous reaction (first transesterification). , increasing the yield of biodiesel production.

[093] Once the transesterification reaction has been satisfactory, biodiesel already separated from glycerine is either water-washed, then heat-dried under reduced pressure or simply silica adsorption and filtration as described. in Brazilian document PI 0502795-0.

[094] Following the removal of alcohol and decantation of glycerine, the biodiesel produced is separated, then washed with water and then subjected to drying under reduced pressure (vacuum);

Characteristic of the ester formed - Biodiesel [095] By carrying out the process of the present invention, a higher conversion rate of 97 to 99% and the high purity of biodiesel are obtained as a result of the drag of the most polar contaminants along with the Glycerinous phase significantly facilitates the framing of biodiesel thus obtained in the European (EN 14214), American (ASTM 6751 D) and Brazilian (ANP 42) quality specifications. EXAMPLE 1 Example of a transformation of vegetable oil into biodiesel using the procedure described in the present invention.

Ex: 100g soybean oil, 100 mL anhydrous ethanol and 4g CuCh.

[098] Triglyceride free reaction within 9 hours, without formation of mono and diglycerides as intermediates.

[099] 4% pure CuCl or CuCl4 catalyst (not associated with adsorbents), 9 hours of reflux reaction at 100 ° C and atmospheric pressure.

[100] The ratio of oil mass (100 g) to alcohol volume (100 mL) always remained fixed by varying the amount of catalyst. When 3% catalyst was used, the reaction time was compromised, ie the reaction was not complete within 9 hours. When 5% was used, the reaction showed the same development as when 4% was used. Also, when a catalyst excess (20%) was used, the reaction time was compromised, so that in 9 hours the reaction was not complete.

Claims

Claims (28)

Transesterification process comprising the steps of: (a) reacting: - a material chosen from the group comprising vegetable and / or animal oils and / or fats containing triglycerides and / or diglycerides and / or monoglycerides and / or fatty acids free; - at least one C1-C5 aliphatic alcohol; at least one heterogeneous catalyst selected from the group comprising CuCl3, CuCl2 and mixture thereof; b) separating the ester and glycerin phases; and c.1) subjecting the ester separated from step b) to a further reaction according to step a); or c.2) washing of the ester separated in b); Process according to Claim 1, characterized in that the reaction time of step a) ranges from 1 hour to 10 hours. Process according to Claim 1, characterized in that the reaction pressure of step a) ranges from 1.0 Kgf / cm2 to 10.0 Kgf / cm2. Process according to Claim 4, characterized in that the reaction pressure of step a) ranges from 1.0 Kgf / cm2 to 3.0 Kgf / cm2. Process according to Claim 1, characterized in that the reaction temperature of step a) ranges from 60 ° C to 110 ° C. Process according to Claim 1, characterized in that the glyceride-rich material is chosen from the group comprising soybean oil, cottonseed oil, corn oil, canola oil, macauba oil, palm oil, peanut oil. , pequi oil, ouricuri oil, jatropha oil, chicken, pork and / or beef tallow fats, frying waste oils and / or mixtures thereof. Process according to Claims 1 and 6, characterized in that the glyceride material is chosen from the group comprising neutral, acidic, crude, degummed, semi-refined and / or refined oils. Process according to Claims 1, 6 and 7, characterized in that the glyceride rich material contains up to 3,000 ppm of water. Process according to Claim 1, characterized in that the C1-C5 aliphatic alcohol is selected from the group comprising methanol, ethanol, propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, amyl and / or isomers thereof and mixture. of the same. Process according to Claim 9, characterized in that the C1-C5 aliphatic alcohol is anhydrous. Process according to Claim 1, characterized in that the heterogeneous catalyst is associated with adsorbing agents, desiccants, sequestrants of inorganic and organic substances, and a mixture thereof. Process according to Claim 11, characterized in that the dissecting agent is Al 2 O 3. Process according to Claim 11, characterized in that the sequestering agent of inorganic and organic substances is S1O2. Process according to Claims 1, 11, 12 and 13, characterized in that the adsorbing, dissecting and sequestering agents of inorganic and organic substances have a concentration ranging from 0% to 5% w / w by weight. total oil employed. Process according to Claim 1, characterized in that the C1-C5 aliphatic alcohol: glyceride material ratio is in the range of 15 g C1-C5 alcohol per 1000 g glyceride material to 1000 g C1-C5 alcohol per 1000 g. glyceride material. Process according to Claims 1 and 15, characterized in that the C1-C5 aliphatic alcohol: glyceride material ratio ranges from 150 g C1-C5 alcohol per 1000 g glyceride material to 1000 g C1-C5 alcohol per 1000 g glyceride material during process step a). Process according to Claims 1 and 15, characterized in that the C1-C5 aliphatic alcohol: glyceride material ratio is in the range of 15 g C1-C5 alcohol per 1000 g glyceride material to 100 g C1-C5 alcohol per 1000 g glyceride material during process step c.1). Process according to Claim 1, characterized in that the heterogeneous catalyst: glyceride material ratio is in the range of 0.1 g heterogeneous catalyst per 1000 g glyceride material to 90 g heterogeneous catalyst per 1000 g glyceride material. Process according to Claims 1 and 18, characterized in that the heterogeneous catalyst: glyceride material ratio is in the range 1.0 g heterogeneous catalyst per 1000 g glyceride material to 90 g heterogeneous catalyst per 1000 g glyceride material during step a) of the process. Process according to Claims 1 and 18, characterized in that the heterogeneous catalyst: glyceride material ratio ranges from 0.1 g heterogeneous catalyst per 1000 g glyceride material to 9.0 g heterogeneous catalyst per 1000 g material. glyceride during step c.1) of the process. Process according to Claim 1, characterized in that it comprises an additional filtration step. Process according to claim 21, characterized in that filtration takes place between steps a) and b). Process according to Claim 21, characterized in that filtration takes place between steps b) and c.1). Process according to Claim 21, characterized in that filtration occurs between steps b) and c.2). Process according to claim 1, characterized in that step b) comprises the use of temperatures ranging from 50 ° C to 100 ° C, centrifugal and / or inducing agents. Process according to Claim 25, characterized in that it further uses reduced pressure. Process according to Claim 25 or 26, characterized in that the evaporated alcohol is condensed and optionally reused in the process. Process according to Claim 1, characterized in that the washing step c.2) comprises: a) washing with water; b) drying by heating and / or reduced pressure; c) adsorption and filtration with silica; d) mixtures of steps a), b) and / or c).