CN101688150A

CN101688150A - Biodiesel production

Info

Publication number: CN101688150A
Application number: CN200880011098A
Authority: CN
Inventors: 沃尔特·奥施曼
Original assignee: DALRIADA MEAT Pty Ltd
Current assignee: DALRIADA MEAT Pty Ltd
Priority date: 2007-02-02
Filing date: 2008-02-01
Publication date: 2010-03-31
Also published as: EP2118250A1; WO2008092207A1; AU2008210273A1; KR20090121298A; AR065168A1

Abstract

A process for producing alkyl fatty acid esters suitable for use as a fuel and/or lubricant. The process includes treating a feedstock containing glycerides and/or free fatty acids with a lipase, a lower alkyl alcohol and an acid catalyst under conditions to produce said alkyl fatty acid esters.

Description

Production of biodiesel

[01] the application requires the right of priority of No. the 2007900488th, the Australian temporary patent application submitted on February 2nd, 2007.Introduce in this content this application.

Technical field

[02] the application relates to the method for the alkyl fatty acid ester mixture that is used to produce the fuel, fuel dope and the lubricant that are suitable for use as such as biofuel.The application also relates to the fuel such as biofuel that adopts described method to produce, and the system that is used to produce described fuel.

Background technology

[03] energy demand of modern society more than 85% is satisfied by burning such as fossil oil such as coal, oil and gas.Yet fossil oil is the non-renewable energy, and the supply of these fuel is limited.

[04] we depend on fossil oil and the environment, health, politics and the social influence that cause are well-known.Human combustion of fossil fuels is the largest source of Carbon emission, and carbonic acid gas is one of greenhouse gases that cause Global warming.

[05] need the alternative form of the energy to satisfy the global energy demand that increases day by day now.The example of the substitute energy form of developing comprises nuclear energy, hydrogen fuel and sun power.Yet these substitute energys all need for every kind Infrastructure is carried out substantial the improvement again so that they can be used constantly with economically.

[06] biofuel is substituting of fossil oil, but does not have the such negative environmental consequences of fossil oil, because biofuel derives from the carbonic acid gas of environment, and can not increase the net carbon dioxide amount in the environment.In addition, use biofuel not need as some other substitute energy, to require substantially to change existing Infrastructure and machinery.

[07] biofuel with plant-sourced or animal source oil or fat produce, biodegradable, be used in the transport fuels in the diesel engine.Biofuel is as the component of diesel-fuel or substituting as diesel-fuel.Biofuel can directly be used in the diesel-engine vehicles, not exhausted vegetable oil (SVO) or depleted vegetable oil (WVO) that this makes biofuel be different to be used as fuel in the diesel-engine road vehicle of some remodeling.Biofuel is biodegradable and nontoxic, and with compare discharging based on the engine of gasoline with remarkable minimizing, so it can cause substantial environmental benefits.

[08] biofuel made from animal source fat has than mineral sources or plant-sourced diesel oil/biodiesel fuel or the better lubricated index of mixture, has remarkable influence (for example referring to " Diesel Fuel Lubricity Reviewed " by reducing the engine components wearing and tearing for engine maintenance, Paul Lacey, SowthwestResearch Institute, Steve Howell, MARC-IV Consulting, Inc., SAE paper 982567, international Fall fuels and lubricants Congress and Exposition, Oct.19-22,1998, San Francisco, California.)

[09] in addition, with the cetane index horizontal exceeding ASTM D6751-07B biofuel standard that the biofuel of animal source fat and high saturated vegetation fat manufacturing has, this standard code the minimum requirements of No. 47 n-Hexadecane.The average cetane index level that the numerous studies of worldwide university and research institution is pointed out, point out from the n-Hexadecane number of the biofuel of animal fat from for from the biofuel of lard about 72 to 61 scope for the yellow grease biofuel (for example referring to National BiodieselBoard " NBB, 2005a).

[10] use the alternative extensive welcome that be subjected to environment protection tissue and corporations of biofuel as petroleum diesel.Biofuel is the main recyclable fuel in Europe, and as a part that reduces the greenhouse gas emission measure, European Union is just encouraging to use biofuel.For example, 2003 EU Biofuels Directive require 2010 the end of the year transport trade 5.75% energy from renewable energy source, be increased to 20% to the year two thousand twenty.

[11] biofuel is made up of the mixture of the multiple single alkyl ester of longer chain fatty acid, and produces by using acid or alkaline catalysts with methyl alcohol vegetable oil or animal tallow to be carried out transesterify usually.For example, International Patent Application WO 03/022961 described a kind of be used for by under the situation about existing at sulfonic acid with the methyl alcohol transesterify with waste oil or oily co-production method of bio-diesel oil.In another example, International Patent Application WO 2006/128881 has been described a kind of being used for by with methyl alcohol rapeseed oil and sunflower seed oil being carried out transesterify and the production method of bio-diesel oil under the situation about existing at sodium hydroxide.Also proposed to pass through the catalytic vegetable oil transesterification reaction production biofuel of enzyme (column candiyeast (Candida cylindracea)) (for example referring to No. the 2005/0084941st, laid-open U.S. Patents application).

[12] although integrating biofuel has been successful as transport fuel substantially, some problems are arranged still in use.For example, one of physical property that can in use cause problem of biofuel is the temperature (" gelling temp ") that fuel begins gel.Along with temperature reduces, the viscosity of biofuel increases and the final crystallization of solution.At last, formed crystal becomes greater to the hole that is enough to stop up fuel filter.The gelling temp of pure biofuel changes according to the glycerine composition that forms biofuel, therefore, depends on the stock oil that is used for the production biofuel.Usually, the saturated fatty acid content of glycerine composition is high more, and the gelling temp of the biofuel that is formed by this material is high more.For example, use biofuel that prior art produces with butter, plam oil or Oleum Cocois often at+15 ℃ to 16 ℃ gels.Many kinds in these biofuel also have relatively poor permanent stability.

[13] need method to be used to produce the true tumor diesel oil fuel of some shortcoming that does not have the prior art biodiesel fuel.

[14] quoting patent document or other document that provides as prior art in the literary composition, is not that to be intended to approve of those files or document any be known before the priority date of claim or information that it comprises is the part of common practise.

Summary of the invention

[15] the present invention results from the research of being carried out with butter production method of bio-diesel oil.We have found that, can handle butter and other suitable animal tallow and vegetables oil and it be carried out transesterification reaction with lipase and be better than many current biodiesel fuels that get biodiesel fuel with production performance with ethanol or other lower alkyl alcohol.

[16] the invention provides a kind of method that is used to produce the alkyl fatty esters that is suitable for use as fuel and/or lubricant, described method is included under the condition and contains the raw material of glyceryl ester and/or free fatty acids to produce described alkyl fatty esters with lipase, lower aliphatic alcohols (lower alkyl alcohol) and acid catalyst processing.

[17] can be at first handle the described raw material of glyceryl ester and/or free fatty acids that contains to produce the first alkyl fatty acid ester mixture with lipase existing under the situation of lower aliphatic alcohols, the described then first alkyl fatty acid ester mixture reacts with described lower aliphatic alcohols under the situation that described acid catalyst exists, and produces the second alkyl fatty acid ester mixture that is suitable for use as fuel and/or lubricant.

[18] the present invention also provides prepared according to the methods of the invention alkyl fatty acid ester mixture.

[19] the present invention further provides the prepared according to the methods of the invention biodiesel fuel.

[20] the present invention also is provided for the system that is suitable for use as the alkyl fatty esters of fuel and/or lubricant produced according to the invention in described method.

[21] the described raw material that contains glyceryl ester and/or free fatty acids can be vegetables oil or animal tallow.In fact method of the present invention is particularly suitable for butter production biofuel.

[22] described lipase can be emulsion lipase (latex lipase) and/or be selected from vegetation fat enzyme (plant lipase) to be derived from high fat content cereal, beans (legume) or seed.Be suitable for and vegetation fat enzyme combination from the emulsion lipase of pawpaw plant from rice bran.Effectively emulsion lipase can be the papoid such as papaya emulsion lipase, and the vegetation fat enzyme can be a tikitiki lipase.Yet, will also be appreciated that emulsion lipase and/or vegetation fat enzyme can not be single enzymes, and in fact can be the mixture of plurality of enzymes.Described effective enzyme can partly or wholly be purified and be used in the method for the invention.Vegetation fat enzyme or emulsion lipase from several other plants also can be used in the method for the invention.Described lipase also can be the suitable lipase of microbial source.

[23] be not to be intended to by any concrete one theory, we believe that lipase can show certain selectivity for the lipid acid of less chain length in the raw material.The transesterify of the glycerine of Lock-in in all right catalysis vegetables oil of described lipase or the animal tallow.In addition, the effect of acid catalyst is further auxiliary ester permutoid reaction.We believe that the effect of lipase and acid catalyst provides stable biodiesel fuel product and this biodiesel fuel product has than not using lipase and acid catalyst to make up the low gelling temp of formed corresponding product.

[24] described lipase can be fixed on the substrate.For example, described gel lipase can be fixed on the substrate that forms with sucrose and brown coal.In one embodiment of the invention, described substrate is the Acid precipitation of brown coal alkalescence extract and the pyrolyzed mixture of sugar.

[25] described lower aliphatic alcohols can be selected from one or more in the group of being formed with methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, sec-butyl alcohol and the trimethyl carbinol.In one embodiment of the invention, described lower aliphatic alcohols is an ethanol.

[26] described acid catalyst can be the mineral acid such as sulfonic acid.

The reaction of [27] first alkyl fatty acid ester mixtures and lower aliphatic alcohols can be carried out under successive reaction rectifying condition, any unreacted lower aliphatic alcohols from reaction distillation returns reaction mixture thus, and the second alkyl fatty acid ester mixture distills from reaction mixture.

[28] can handle (for example separating) through the distillatory second alkyl fatty acid ester mixture, to remove unreacted glycerine and soap by proportion.Thus obtainedly can be used as biofuel through the second alkyl fatty acid ester mixture of purifying.Yet, we have found that advantageously the second alkyl fatty acid ester mixture and Rice pollard oil ester mixture mixed the alkyl fatty acid ester mixture that is suitable for use as fuel with formation mutually.Can be by making Rice pollard oil and lower aliphatic alcohols exist under the situation of methylsulfonic acid reaction to prepare the Rice pollard oil lipoprotein mixture.Described lower alkyl alcohol can be a propyl carbinol.Propyl carbinol can be by from forming through the glycerine of the distillatory second alkyl fatty acid mixture separation and the enzymic hydrolysis of soap mixture.

Description of drawings

[29] below in conjunction with some aspect a plurality of embodiment illustrated in the accompanying drawings the present invention is described.In described accompanying drawing:

[30] Fig. 1 is the schema that a plurality of details that are used for the production method of bio-diesel oil according to an embodiment of the invention are shown.

[31] Fig. 2 (a) is the first part of schema that the details of the early part that is used for the production method of bio-diesel oil according to an embodiment of the invention is shown.

[32] Fig. 2 (b) be illustrate method shown in Fig. 2 (a) late period part details and with the second section of Fig. 2 (a) successive schema.

Embodiment

[33] will illustrate in greater detail various embodiments of the present invention now.Yet, it must be understood that following explanation does not limit the versatility of above-mentioned explanation.Use in the following description with Fig. 1 to 2 in the corresponding label of the label that uses.

[34] the invention provides the method that is used to produce the alkyl fatty esters that is suitable for use as fuel and/or lubricant.Present method is useful especially for producing high quality biologic diesel oil with low-grade relatively raw material.

[35] described method is included under the condition that produces alkyl fatty esters and handles the raw material 12 that contains glyceryl ester and/or free fatty acids with lipase 14, lower aliphatic alcohols 16 and acid catalyst 18.

[36] handle the raw material 12 that contains glyceryl ester and/or free fatty acids with lipase 14, lower aliphatic alcohols 16 and acid catalyst 18 in turn.Among the embodiment shown in Figure 1, in first step, under the situation that has lower aliphatic alcohols 16, handle the described raw material 12 of glyceryl ester and/or free fatty acids that contains to produce the first alkyl fatty acid ester mixture 20 with lipase 14, the described then first alkyl fatty acid ester mixture 20 reacts with described lower aliphatic alcohols 16 under the condition that acid catalyst 18 exists, and produces the second alkyl fatty acid ester mixture 46.

[37] glyceryl alcohol that contains vegetables oil or animal tallow is especially suitable for use as raw material 12.Term " glyceryl alcohol that contains vegetables oil or animal tallow " means any plant or zoogenous oil or the fatty prod that contains with glycerine and the formed ester of lipid acid (being glyceryl ester) as used herein.Glycerine has three hydroxyl functional groups, and described three hydroxyl functional groups can carry out transesterify with one, two or three lipid acid, and form monoglyceride respectively, diglyceride and triglyceride.Vegetables oil and animal tallow mainly contain triglyceride, although they also contain some monoglycerides and diglyceride usually.The described glyceryl ester that contains vegetables oil and animal tallow can be selected from following group: animal tallow, vegetables oil, exhausted cooling oil ﹠ fat, seed, seed residue raw material and waste oil (grease trap oil).

[38] animal tallow is the fat that obtains from animal source.The suitable animal tallow that can be used to make biofuel comprises: butter (beef fat), lard (pork fat), chicken fat (chicken fat), blubber, Oils,glyceridic,cod-liver, butter and the byproduct when making omega-3 lipid acid with fish oil.For example, we have found that method of the present invention is particularly suitable for butter are converted into biodiesel fuel.

[39] the suitable vegetables oil that can be used to make biofuel comprises: rapeseed oil, soya-bean oil, plam oil, tori seed oil, Viscotrol C, Oleum Cocois (copra oil), Semen Maydis oil, continuous seed oil, false flax oil (false flaxoil), hempseed oil, peanut oil, radish oil, Semen Sesami Nigrum oil (ramtil oil), Rice pollard oil, Thistle oil, sunflower seed oil, tung oil, algae oil, oleum copaibae (copaiba oil), pretty young woman's oil (honge oil), Cortex jatrophae oil, jojoba oil, milk shrub oil, the oil macadamia nut oil, walnut oil, sunflower seed oil, reach silent oil, linseed oil, seed of Papaver somniferum L. powder (poppyseed oil), Herba Lobeliae Chinensis oil (bladderpod oil), Oleum Fructus Bruceae, bardane oil (plug oil), tung tree (Kuku she macadamia nut oil), seed of Radix Dauci Sativae oil, Oleum Hydnocapi semen, Krona cloth oil, calyx is apart from caul-fat, lemon oil, orange oil, mango oil, mowrah butter (mowrah butter), nim oil, rose-seed oil, Oleum Hippophae, shea butter, pod lotus seed oil (snowball seed oil) (Viburnum dilatatum oil), Yatall MA (tall oil), tamanu oil (tamanuoil), soya-bean oil, and Ocimum basilicum L. soya-bean oil (fragrant two wing soya-bean oil (cumaru oil)).

[40] lower aliphatic alcohols (lower alkyl acohol) 16 can be a C1-C6 alcohol.In one embodiment of this invention, lower aliphatic alcohols 16 is selected from one or more in the group of being formed with methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, sec-butyl alcohol and the trimethyl carbinol.Methyl alcohol is normally used alcohol in production of biodiesel, but we find that ethanol is specially adapted in the method for the present invention.Lower aliphatic alcohols 16 is about 1: 1 mol ratio with the ratio of the glyceryl ester that contains vegetables oil or animal tallow 12 in mix flow 28.

[41] contain glyceryl ester and or the raw material supply stream 22 of the raw material 12 of free fatty acids send to by flow control device 24, and make up with adjustings stream from the lower aliphatic alcohols 16 of syringe pump feeding.Mix flow 28 mixes by static mixer 30.React under the situation that the mix flow 28 that contains lower alkyl alcohol 16 and vegetables oil or animal tallow 12 is having lipase 14 to exist in suitable reaction vessel 32.Reaction vessel 32 is can be temperature controlled.

[42] lipase 14 can be vegetation fat enzyme and/or the emulsion lipase that is derived from high fat content cereal, beans or seed.In one embodiment of the invention, lipase 14 is the combinations that are derived from the vegetation fat enzyme and the emulsion lipase of high fat content cereal, beans or seed.As used herein, term " lipase " means the enzyme of the hydrolysis of catalysis triglyceride.Term " emulsion lipase " means the lipase of finding naturally in the emulsion of plant.Many floristics have the emulsion that contains lipase.This kind of plant kind includes, but not limited to pawpaw, mango, Guo Lan (sapote), mulberry fruit, Fructus Fici, Kiwifruit and blackberry, blueberry.Emulsion lipase can be used as natural mixture, half purifying mixture and uses, and perhaps described lipase can be purified.Can use standard method to obtain emulsion, for example beat the fruit of plant and collect effusive emulsion from plant.Emulsion can be frozen being used for storage, and/or can be by the cold natural solid emulsion lipase preparation that is suitable for using to obtain of doing.Alternatively, emulsion lipase can use such as the known protein matter purification techniques of chromatography and purify.

[43] in one embodiment of this invention, use is from the emulsion lipase of pawpaw plant.Emulsion from pawpaw is used with the form---papoid---of proteolytic enzyme preparation in food and drink industry.That can buy natural form from Sigma-Aldrich or cold dry form from pawpaw emulsion (CAS numbering: papoid 9001-73-4) (EC 3.4.22.2) (for example, article No. P4762).Active emulsion lipase can be the papoid lipase such as papaya emulsion lipase.

[44] term " from the vegetation fat enzyme of high fat content cereal, beans or seed " means the lipase of finding naturally in having any cereal, beans or the seed of high relatively fat content.This kind cereal, beans or seed include, but not limited to Semen Ricini, rice bran, wheat bran, oat bran, rye, oil-containing beans, oleaginous seed (as Semen Brassicae campestris).The rice bran fats endonuclease capable uses with the form of the preparation that ground rice bran or half is purified or purified.Be used for from the method that rice bran extracts lipase be known (for example, referring to Prabhu, A.V/et al., Biotechnol Prog.1999; 15 (6): 1083-9).

[45] employed lipase can not be single or homogeneity, in fact can be the mixture of different lipase.Described lipase can also contain certain micro-organisms lipase.In addition, active lipase can partly or wholly purify and use in the method for the invention.

[46] lipase 14 can be solidificated on the substrate.An important factor is to be used for catalyzer solidified proper method for the economical efficiency of catalytic process, allowing easily to reclaim and repeatedly to use catalyzer, and if possible, increases its stability under reaction conditions.In order to understand the curing of lipase, for example referring to F.X.Malcata et al., J.Am.Oil Chem.Soc.1990,67,890-910.

[47] in the embodiment of the invention that illustrates, lipase 14 is imported in the mix flow 28 by static mixer 34 and is fed to reaction vessel 32.The ratio of lipase and glyceryl ester can be about 1: 10w/w is to about 1: 30w/w.Reactant is mixed continuously and is reflected at about 30 ℃ to carry out to about 70 ℃ temperature.Reaction can continue from about 30 minutes to about 90 minutes time durations.

[48] after the required time of process in reaction vessel 32, the first alkyl fatty acid ester mixture 20 is pumped from reaction vessel 32 by flowrate control valve 38.The first alkyl fatty acid ester mixture 20 can separate from the solid material such as solidified lipase 14.The first alkyl fatty acid ester mixture 20 can use any suitable technology (include, but not limited to mechanical separation, filtration, gravity separation, centrifugal or the like) to realize from the separation of solidifying lipase 14 and/or other solid material.In one embodiment of this invention, realize described separation by centrifugation.Like this, the first alkyl fatty acid ester mixture 20 can be pumped to whizzer 40 by flowrate control valve 38 from reaction vessel 32.The first alkyl fatty acid ester mixture 20 through purifying can common mode take out from whizzer.Whizzer waste 41 can be pumped to peel groove (strippingtank) 43, and at this, solidified lipase can be extracted and be back to reaction vessel 32.

[49] then, under the situation of existence acid 18, reacting to form the second alkyl fatty acid ester mixture 46 of obtaining after the centrifugal treating with lower aliphatic alcohols 26 through the first alkyl fatty acid ester mixture 20 of purifying.Lower aliphatic alcohols 16 can be any alcohol that discussed the front in the literary composition, in one embodiment, is ethanol.Acid catalyst 18 can be any suitable mineral acid, all example hydrochloric acids, sulfonic acid etc.In one embodiment of the invention, described mineral acid is a sulfonic acid.

What obtain after [50] centrifugal can carry out under any suitable condition with the reaction of lower aliphatic alcohols 16 under there is the situation of mineral acid in the first alkyl fatty acid ester mixture 20 of purifying.The pure and mild mineral acid of lower aliphatic can mix in the following manner: mineral acid is about 1.5%w/w of glyceryl ester, the mol ratio of lower aliphatic alcohols and glyceryl ester is 12: 1 on volume.Usually, described reaction needed heating.In one embodiment of the invention, describedly be reflected under the reaction distillation condition (such as under the successive reaction distillation condition) and carry out.Like this, alkyl fatty acid ester mixture 20, lower aliphatic alcohols 16 and the mineral acid 18 through purifying is fed to reactive distillation column 50 by heated static mixer 48.Heated static mixer 48 can about 50 ℃ to about 70 ℃ temperature.In one embodiment of the invention, heated static mixer is in about 60 ℃ temperature.

[51] successive reaction distillation is carried out in tower and reboiler device 50, and reaction product flow to reboiler by the overflow pipe chip system of flowing through.We have found that, comprise that the chip system of the sheet that forms with the net through extending is effective especially.Net through extending can be stainless (steel) wire, zinc-plated steel mesh or nickel type steel mesh.Use this kind system, we can obtain 97% conversion.In reboiler 50, be reflected at about 110 ℃ and to about 180 ℃ temperature, carry out.In one embodiment of the invention, being reflected at about 125 ℃ carries out to about 165 ℃ temperature.Unreacted lower aliphatic alcohols is evaporated and to the upper reaches, and condensation and recirculation are returned in heated static mixer 48 inflows.In this way, the unreacted lower aliphatic alcohols from reaction distillation is returned to reaction mixture.The second alkyl fatty acid ester mixture 46 distills from reaction mixture.

[52] in the embodiment of the invention shown in Fig. 2 (a) and 2 (b), lipase 14 is to be derived from the vegetation fat enzyme 14b of high fat content cereal, beans or seed and the composition of emulsion lipase 14a.We have found that emulsion lipase 14a that is derived from the pawpaw plant and the vegetation fat enzyme 14b combination that is derived from rice bran are effective.

[53] emulsion lipase 14a can be solidificated on the substrate.We have found that the substrate that forms with saccharides and brown coal is suitable especially.Brown coal can be derived from the Acid precipitation of brown coal alkalescence extract.We have found that the micronization pyrolyzed mixture of brown coal extract and sugar is especially suitable for use as the substrate of pawpaw emulsion lipase 14a.Described substrate can form in the following manner.At first brown coal are extracted the sour composition (for example, humic acid, fulvic acid etc.) of brown coal then by micronization under alkaline condition.The suitable alkali that is used for the alkalescence extraction comprises potassium hydroxide, magnesium hydroxide and magnesium sulfide.The pH regulator that will react enriched material then is to about 3 to about 5.We have found that about 4.0 to about 4.5 pH is suitable especially.The sedimentary sour composition that is extracted of brown coal removes by filtration in this way.Then, segregate throw out mixes mixture pyrolysis under the temperature between about 240 ℃ to about 800 ℃ then with carbohydrate such as (but being not limited to) honey, sucrose etc.The pyrolyzed mixture of sugar that forms like this and brown coal extract is as the substrate of pawpaw emulsion lipase then.

[54] illustrate as the best among Fig. 2 (a), pawpaw emulsion lipase 14a imports in the mix flows 28 with the vegetation fat enzyme 14b (with the form of rice bran 19) that is derived from high fat content cereal, beans or seed by static mixer 30 and is fed to the reaction vessel 32 that contains lower aliphatic alcohols 16 and vegetables oil or animal tallow 12.Rice bran 19 can be from the rice bran resistates of the on-the-spot transesterification reaction of Rice pollard oil in the illustrated process after a while.

[55] pawpaw emulsion lipase 14a can be about 1 with the ratio of vegetables oil or animal tallow: 10w/w is to about 1: 30w/w.In one embodiment of the invention, pawpaw emulsion lipase 14a can be about 1 with the ratio of vegetables oil or animal tallow: 20w/w.Reactant is mixed continuously, and is reflected at from about 30 ℃ and carries out to about 70 ℃ temperature.In one embodiment of the invention, described being reflected under about 50 ℃ temperature carried out.Described reaction can continue from about 30 minutes to about 90 minutes time durations.In one embodiment of the invention, described reaction continues about 60 minutes time.

[56] after the required time of process in reaction vessel 32, the first alkyl fatty acid ester mixture 20 is separated from the solid material such as solidified lipase 14a and rice bran 19 by foregoing centrifugal method.Then, under the situation of existence acid 18, reacting to form the second alkyl fatty acid ester mixture 46 as previously mentioned of obtaining after the centrifugal treating with lower aliphatic alcohols 16 through the first alkyl fatty acid ester mixture 20 of purifying.The second alkyl fatty acid ester mixture 46 distills from reaction mixture then, and is extracted continuously from reboiler 50 by flowrate control valve 54 by pump 52.

[57] second alkyl fatty acid ester mixtures 46 can directly be used as or be used as biofuel after purifying, and perhaps can be further processed.For example, can be processed through the distillatory second alkyl fatty acid ester mixture to remove unreacted glycerine.Described processing can comprise gravity separation.Like this, the second alkyl fatty acid ester mixture 46 can be pumped to static glycerine/alkyl ester separation device container 56 by flowrate control valve 54 by pump 52.Separator vessel 56 is used for raw glycerine is separated from alkyl fatty acid ester mixture 46 (its top layer from separator vessel 56 is taken away continuously) with unreacted glyceryl ester 58.

[58] raw glycerine and unreacted glyceryl ester 58 (being the bottom of separator vessel) can be recycled.For example, unreacted glyceryl ester and unreacted ethanol can be based on the proportions of each composition and are separated from raw glycerine and soap.Like this, raw glycerine and glyceryl ester 58 can be pumped to whizzer 60 from separation vessel 58, at this, based on proportion they are separated.Whizzer extract 62 (promptly mainly being unreacted glyceryl ester and unreacted ethanol) can be pumped back reboiler 50.

[59] whizzer waste 64 (promptly mainly being raw glycerine and soap) can change into butanols by fermentation.As shown in Fig. 2 (b), whizzer waste 64 can mix with suitable enzyme and be pumped to the multicell rotating biological disc type bio-reactor 68 that has the solidified specific bacteria and be fermented into alcohol by flowrate control valve 66.Butanols preferably uses the production of this kind method.Known many microorganisms produce butanols by fermentation.Had several clostridial species (for example acetone-butanol fusobacterium (Clostridium acetobutylicum), Bai Shi clostridium (Clostridium beijerinckii)) show can the operable butanols of catalysis production (see Jones, D.T.and Woods, D.R.Microbial Rev.1986 Deceber; 50 (4): 484-524).Other enzyme that can be used in this conversion comprise contain microorganism desaturase and/or fungi desaturase through purify or the primary mixture.The alcohol that is generated can distill by water distilling apparatus 70, and with in the reaction that is described in more detail below.

[60] we have found that,, can form good biofuel product if mix with the ester of Rice pollard oil from raw glycerine and unreacted glyceryl ester 58 isolating alkyl fatty acid ester mixtures 46.

[61] the rice bran grease can adopt any suitable esterification or ester-exchange technology and prepare.Yet, we have found that advantageously, use sulfonic acid to prepare the rice bran grease as the catalyzer of transesterification reaction.Suitable sulfonic acid comprises the alkylsulphonic acid such as methylsulfonic acid.Thereby, rice bran can exist under the situation of methylsulfonic acid with the lower aliphatic alcohols reaction to form the Rice pollard oil ester mixture.Lower aliphatic alcohols can be selected from one or more in the group of being formed with methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, sec-butyl alcohol and the trimethyl carbinol.Preferably, described lower aliphatic alcohols is a propyl carbinol.Described propyl carbinol can form by the glycerine that forms during the manufacturing of the foregoing second alkyl fatty acid ester mixture and the enzymic hydrolysis of soap mixture.

[62] rice bran 19 that has about oil component of 19% to about 23%w/w is added into reaction vessel 74 continuously, and mixes mutually with the stream through regulating butanols 76 that is mixed with methylsulfonic acid 78.Butanols 76 and methylsulfonic acid 78 were pumped to static mixer 80 before being injected into reaction vessel 74.Methylsulfonic acid is about 1 with the ratio that is injected into the propyl carbinol in the reaction vessel 74: 40w/w is to about 1: 50w/w.In one embodiment, methylsulfonic acid is about 1 with the ratio of propyl carbinol: 40w/w is to about 1: 50w/w.

[63] every 1Kl alkyl ester 110Kg rice bran may be added to reaction vessel 74.Reaction vessel 74 can be the controlled temperature formula band cover bio-reactor that stirs continuously.Propyl carbinol can be about 1 with the ratio of rice bran: 3w/w to 1: 4w/w.In one embodiment, the ratio of propyl carbinol and rice bran is about 1 in the reactant of beginning: 3.5w/w.

[64] with before the second alkyl fatty acid ester mixture 46 mixes, Rice pollard oil ester mixture 82 can separate from solid material.For example, Rice pollard oil ester mixture 82 can separate from solid material by centrifugation.Like this, Rice pollard oil ester mixture 82 can be extracted and be pumped to whizzer 86 by regulating flowrate control valve 84.Can be pumped to mixing vessel 88 from the extract (being Rice pollard oil ester mixture 82) of whizzer is used for mixing mutually with the second alkyl fatty acid ester mixture 46.

[65] waste 90 of whizzer 86 (promptly mainly being rice bran) can reuse in reaction to produce alkyl fatty acid ester mixture 20.

[66] from the alkyl fatty acid ester mixture 46 of the top layer continuous drawing of separator vessel 56, can in static mixer 92, mix mutually, and be pumped in the continuous pump mixing vessel 94 with Rice pollard oil ester mixture 82.The pH of mixture can be adjusted to about 6 to about 8.In one embodiment of the invention, the pH regulator of mixture is to about 7.

[67] can regulate the pH of described second alkyl fatty esters and Rice pollard oil ester mixture by the medicament 95 that interpolation is selected from the group of being formed with potassium hydroxide, sodium hydroxide, magnesium hydroxide, ammonia and calcium hydroxide.In one embodiment of the invention, regulate the pH of mixture by adding sodium hydroxide.

[68] can handle described second alkyl fatty esters and Rice pollard oil ester mixture with filtering medium 96.Suitable filtering medium 96 can be selected from the group of being formed with diatomite, gac and silicate.Described silicate can be silico-aluminate or magnesosilicate.In one embodiment of the invention, described filtering medium 96 is magnesosilicates.Magnesosilicate is particularly advantageous, because they are not only as filtering medium but also from second alkyl fatty esters and the remaining water of Rice pollard oil ester mixture extraction.

[69] can described filtering medium 96 be separated with the Rice pollard oil ester mixture from described second alkyl fatty esters by mechanical filter.For example, second alkyl fatty esters and Rice pollard oil ester mixture, filtering medium and reacted pH regulator agent can be pumped through being with strainer press (continuous belt filter press) 97 continuously.

[70] filtered alkyl ester is the product 98 that processes, and can remain to be used for storage.We have found that depend on initial starting material, the biofuel of being produced has the gelling temp between about 0 ℃ and 10 ℃.For example, when starting raw material was butter (it is to obtain easily and cheap parent material), we can produce the biofuel with the gelling temp in this scope.These are different with the prior art biodiesel fuel (having been found that it has about 16 ℃ gelling temp) that forms with butter.Thereby, using method of the present invention, we can form high-grade biodiesel fuel with the quite low-grade parent material such as butter.

[71] in addition, the biofuel of using method of the present invention to produce has good permanent stability.For example, we have found that sample does not have tangible oxidation after at room temperature depositing about December in open container.Be not to be intended to be limited to theory, we believe that the oxidative stability of the biofuel of using the inventive method production may be because there is alpha's vitamin-E (alpha tocopherol) in (at least in part) in the finished product.Known rice bran contains quite high-caliber alpha's vitamin-E---and this is the antioxidant that nature exists.We believe, be used in the alpha's vitamin-E in the rice bran 19 in the initial lipase-catalyzed reaction and/or the rice bran 74 that in the production of Rice pollard oil ester mixture 82, uses in alpha's vitamin-E of existing be brought into the finished product 98.Inferring in the preparation of rice bran ester and using methylsulfonic acid is favourable as catalyzer, and reason is its alpha's vitamin-E of can not degrading significantly in some way as other acid catalyst.

[72] method of the present invention can be carried out in the mode of successive, nothing waste.

[73] the finished product are suitable as biofuel, and can directly use or mix use with inorganic diesel oil.For example, the biodiesel fuel of prior art, the ratio of mixture of common inorganic diesel oil and biofuel is 9: 1.This mainly is can be used in amount in the described mixture because the high gelation point of biofuel limits it.Yet the ratio that biofuel produced according to the invention can be about 7: 3 mixes with inorganic diesel oil.

[74] advantageously, we have found that and to be added into the cetane value index that the biofuel product increases the biofuel product by butyl ester Rice pollard oil.

The explanation of specific embodiment

Example 1 production of biodiesel

[75] use preceding method and device fabrication biofuel.Step below particularly adopting.

[76] raw material supply of butter 12 stream 22 is sent into by flow control device 24, and makes up with adjustings stream 26 from the ethanol 16 of syringe pump feeding.Mix flow 28 is mixed by static mixer 30.Mix flow 28 is solidificated under the situation that is formed papaya emulsion lipase on the substrate and tikitiki lipase 14 with sugar and brown coal in existence and reacts in the reaction vessel 32 at controlled temperature.The ratio of lipase and butter is 1: 10w/w and 1: between the 30w/w.Reactant is mixed continuously and be reflected under the temperature between 30 ℃ and 70 ℃ and carried out 30 to 90 minutes.

[77] reaction mixture (containing the first alkyl fatty acid ester mixture 20) is pumped to whizzer 40 from reaction vessel 32 by flowrate control valve 38 then, separates from the solid material such as solidified lipase 14 this its.Extract out from whizzer in common mode through the first alkyl fatty acid ester mixture 20 of purifying.Whizzer waste 41 is pumped to peel groove 43, and at this, solidified lipase is extracted and is back to reaction vessel 32.

[78] then, obtain after the centrifugal treating through the first alkyl fatty acid ester mixture 20 of purifying exist under the situation of sulfonic acid 18 with methyl alcohol 16 reactions to form the second alkyl fatty acid ester mixture 46.Methyl alcohol 16 and sulfonic acid 18 mix with the ratio of about 1.5%w/w sulfonic acid, are that methyl alcohol calculates with 12: 1 mol ratio on volume.Described reaction is carried out under the successive reaction distillation condition with 60 ℃ temperature.Second fatty acid ester blends 46 distills from reaction mixture, and is extracted continuously from reboiler 50 by flowrate control valve 54 by pump 52.

[79] second alkyl fatty acid ester mixtures 46 are transferred in static glycerine/alkyl ester separation device container 56, at this raw glycerine and unreacted glyceryl ester 58 by separating from alkyl fatty acid ester mixture 46 than heavy filtration.Alkyl fatty acid ester mixture 46 is extracted out continuously from the top layer of separator vessel 56.

[80] by being pumped to whizzer 60 from separation vessel 56, reclaim raw glycerine and unreacted glyceryl ester 58 (being the bottom of separation vessel 56), the different specific weight at whizzer 60 places based on each component separates unreacted glyceryl ester from raw glycerine with unreacted ethanol with soap.Whizzer extract 62 (mainly being unreacted glyceryl ester and unreacted ethanol) pumped back reboiler 50.

[81] whizzer waste 64 (mainly being raw glycerine and soap) is pumped to multicell rotating biological dish bio-reactor 68 by flowrate control valve 63, and reactor 68 contains that solidified clostridial species (Clostridium sppbacterial)---it becomes butanols with material fermentation.Distill butanols by water distilling apparatus 70, and it is used in the production of rice bran grease 82.

[82] in order to produce rice bran grease 82, the rice bran 19 that has about oil-contg of 19% to about 23%w/w is added into reaction vessel 74 continuously, and be mixed with mixing mutually of methylsulfonic acid through regulating butanols 76 streams.Butanols 76 and methylsulfonic acid 78 were pumped to static mixer 80 before injecting reaction vessel 74.The methylsulfonic acid of injection reaction vessel 74 is about 1 with the ratio of propyl carbinol: 40w/w is to about 1: 50w/w.Propyl carbinol is 1 with the ratio of rice bran: 3w/w to 1: 4w/w.Every 1Kl alkyl ester is joined the 110Kg rice bran and is added into reaction vessel 74.Reaction vessel 74 can stir and controlled temperature continuously.

[83] Rice pollard oil ester mixture 82 is pumped to whizzer 86 from container 74 extractions and by regulating flowrate control valve 84.Being pumped to mixing vessel 88 from the extract (being Rice pollard oil ester mixture 82) of whizzer is used for mixing mutually with the second alkyl fatty acid ester mixture 46.The waste 90 of whizzer 86 (mainly being rice bran) can reuse in reaction to produce alkyl fatty acid ester mixture 20.

[84] alkyl fatty acid ester mixture 46 mixes mutually with Rice pollard oil ester mixture 82 in static mixer 92, and is pumped in the continuous pump mixing vessel 94.By adding magnesium hydroxide with the pH regulator of mixture to about 7.Add magnesosilicate then as filtering medium and siccative, can magnesosilicate be separated with the Rice pollard oil ester mixture from described second alkyl fatty esters, its pumping process is with strainer press 96 continuously by mechanical filter.

[85] filtered alkyl ester is the product 98 that processes, and can remain to be used for storage.

The characteristic of example 2 biofuel

[86] with in fact at British Standards Institution's recommend method (British Standard Insititution (BSI) reference method) BS EN 14103:2003; The alkyl fatty esters composition of the finished product that the above-mentioned reaction sequence of gas chromatography (GC) methods analyst of describing in " Fat and oil derivatives-Fatty AcidMethul Esters (FAME)-Determination of ester and linolenic acid methyl estercontents " obtains.

[87] however the present invention relates to respectively under the situation that has ethanol or propyl carbinol respectively animal tallow and Rice pollard oil are carried out the formation of the mixture that transesterification reaction produces to produce fatty alkyl ethyl ester and fatty alkyl butanols respectively.Therefore, in the purport of EN 14103:2003 standard, the present invention report is used for identifying fully that all of sample must information; The employed method of sampling; Testing method in conjunction with the European standard use; And the test result that obtains.

[88] use is equipped with and uses the HP-innowax capillary column (1909N-113 of high purity helium as carrying gas; J﹠amp; W Scientific; (Agilent Technologies Wilmington, DE USA) analyze fatty alkyl ethyl ester (FAEE) and fatty alkyl butyl ester (FABE) in the Agilent 7890A GC system of 30m * 320um * 0.25um) and flame ionization detector (FID).Identical temperature programmed condition is adopted in the analysis of FAEE and FABE: 140 ℃ continue 0 minute, and 5 ℃ then/min to 220 ℃ continues 3 minutes, and 20 ℃ then/min to 260 ℃ continues 8 minutes.

[89] contrast commercially available FAEE standard substance (FAEE standards) (Nu-Chek Prep, Inc., Elysian, MN, USA) mixture is discerned FAEE by the hold-time (retention time), and its branch is in containing the heptane of 0.005% (w/w) butylated hydroxyanisol as antioxidant.Contrast by can buy the FABE mixture that (Nu-Chek) prepares of triacylglycerol (TAG), FABE demarcated with its hold-time.In order to prepare FABE, 10mg simple substance alkyl fatty acid (about sn-1, sn-2, sn-3 part) TAG is dissolved in trichloromethane/methyl alcohol (9: 1v/v, contain 0.005% (w/v) butylated hydroxyanisol as antioxidant) in, under nitrogen environment dry and with the solution of 2.5% (v/v) methylsulfonic acid in propyl carbinol of 2ml (final methylsulfonic acid be that reacted 3 hours at 80 ℃ (1: 40v/v)) with the ratio of propyl carbinol.After cooling, by using about 1: 1: 1.2: the propyl carbinol of 1.3 (volume ratios): water: methyl alcohol: heptane is separated and from the heptane FEBE that extracts, perhaps by according to sample basis (sample basis) requirement of sample being changed the ratio of each solvent and optionally break the described phase FEBE that extracts.Heptane several FABE in mutually use soda ash dryings the whole night, and each FABE puts in order in the 2ml heptane then, adds cap under nitrogen environment.For FAEE and FABE, prepare the suitable mixing of each ester so that can discern all main peaks from the tomographic map of all biofuel samples.

[90] wt (%) of total fatty acids is determined and be expressed as to the quantity of the unsaturated double bond followed by its carbon length of lipid acid.FA (ee); Fatty-acid ethyl ester; Be; FA (be); Fatty acid butyl ester.Other lipid acid represents to have the lipid acid of hold-time greater than C22:6n-3ee or C22:6n-3be.

[91] table 1 illustrates under situation about existing at ethanol and sulfonic acid afterwards the fatty acid component of handling the resulting mixture of transesterify of the animal tallow stage 1 of biofuel method of material with solidified vegetation fat enzyme.The fatty alkyl ester of discerning in this mixture only is the ethyl ester type, rather than for the described methyl esters of other biodiesel blend.Ethyl ester mainly is C 16:0 (cetylate) 23.8%, C 18:0 (stearate) 22.2% and C 18:1cis 9 (oleic acid (oleate)) 37.9%, and the aggregate level of saturated fatty acid is 48.2%, and is consistent with the lipid acid in the zoogenous parent material.Detected minimum fatty-acid ethyl ester comprises the isomer of C18:1, perhaps is elaidic acid ethyl ester and/or isooleic acid ethyl ester and hold-time to be longer than C22:6 and perhaps is the ethyl ester of C24 ethyl ester type.

The fatty acid analysis of the biodiesel blend that table 1 is produced by the transesterify of animal tallow

(biofuel sample #2)

[92] table 2 illustrates the fatty acid component of the resulting mixture of transesterify of the Rice pollard oil from the stage 2 of the biofuel method of processing material under the situation of butanols and methylsulfonic acid existence.Fatty alkyl ester in this mixture only is the butyl ester type, rather than for the described methyl esters of other biodiesel blend with for described ethyl ester of stage 1 of the present invention.Butyl ester mainly is C 16:0 (cetylate) 19.1%, C 18:1cis 9 (oleic acid (oleate)) 32.7% and 18:2 (linolic acid) 28.7%, and the aggregate level of saturated fatty acid is 23.6%, and is consistent with the lipid acid in the beginning material of plant-sourced.Detected several other fatty alkyl ethyl esters, but these fatty alkyl ethyl esters be difficult to determine definitely with the butyl ester standard substance that can get, comprise about 14.5% of total fatty acids ester in this sample altogether.

The fatty acid analysis (biofuel sample #3) of the biodiesel blend that table 1 is produced by the transesterify of Rice pollard oil

[93] table 3 illustrates from handling the transesterify of animal tallow stage 1 of biofuel method of material with solidified vegetation fat enzyme and the fatty acid component of the resulting combination mixture of transesterify of Rice pollard oil from the stage 2 of the biofuel method of handling this material under the situation that propyl carbinol and methylsulfonic acid exist under the situation that has ethanol and sulfonic acid after a while.Ethyl ester comprises the about 91% of total fatty alkyl ester in this mixture, and butyl ester comprises about 9% of total fatty alkyl ester.Whole fatty alkyl ester components of this biodiesel blend are depicted as total %FAEE and add FABE (left-hand line) and %FAEE or %FABE (right-hand column).Matched well shown in FAEE curve and the table 1, and for butyl ester, main kind is represented C 16:1 (18.0%), C18:1 (30.1%) and C 18:2 (30.0%), in the also similar table 2 for the ratio shown in the table 2 that obtains rice bran from the fatty alkyl butyl ester.Other fatty alkyl ester that in biofuel sample #3, exists (owing to butyl ester in this mixture is difficult to determine to the quite low ratio of ethyl ester) comprise total ester content about 2.0% or total butyl ester 21.9%.

The fatty acid analysis of the biofuel that table 3 is produced by the transesterify of animal tallow and Rice pollard oil.(biofuel sample #4)

[94] only by some embodiments of the present invention have been described, and the remodeling within the spirit and scope of the invention can be expected.Thereby, it must be noted that, there are other variation and remodeling for structure (it is also within the scope of the invention) described in the literary composition.

Claims

1. method that is used to produce the alkyl fatty esters that is suitable for use as fuel and/or lubricant, described method comprise under certain condition to be handled and contains the raw material of glyceryl ester and/or free fatty acids to produce described alkyl fatty esters with lipase, the pure and mild acid catalyst of lower aliphatic.

2. method according to claim 1, wherein handle the described raw material of glyceryl ester and/or free fatty acids that contains to produce the first alkyl fatty acid ester mixture existing under the situation of described lower aliphatic alcohols with described lipase, the described then first alkyl fatty acid ester mixture exists under the situation of described acid catalyst and described lower aliphatic alcohols reaction, is suitable for use as the second alkyl fatty acid ester mixture of fuel and/or lubricant with production.

3. method according to claim 1 and 2, wherein said lipase are selected from one or more in the group of being formed with vegetation fat enzyme that is derived from high fat content cereal, beans or seed and emulsion lipase.

4. method according to claim 3, wherein said lipase are the compositions of emulsion lipase and vegetation fat enzyme.

5. according to claim 3 or 4 described methods, wherein said emulsion lipase is pawpaw emulsion lipase.

6. method according to claim 5, wherein said pawpaw emulsion lipase are solidificated on the substrate that forms with sucrose and brown coal.

7. method according to claim 6, wherein said substrate are the pyrolyzed mixture that is derived from brown coal alkalescence extract Acid precipitation and carbohydrate.

8. according to each described method in the claim 3 to 7, the vegetation fat enzyme that wherein is derived from high fat content cereal, beans or seed is a tikitiki lipase.

9. according to each described method in the aforementioned claim, the wherein said raw material that contains glyceryl ester and/or free fatty acids is vegetables oil or animal tallow.

10. method according to claim 9, the wherein said raw material that contains glyceryl ester and/or free fatty acids is butter.

11. according to each described method in the aforementioned claim, wherein said lower aliphatic alcohols is selected from one or more in the group of being formed with methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, sec-butyl alcohol and the trimethyl carbinol.

12. method according to claim 11, wherein said lower aliphatic alcohols is an ethanol.

13. according to each described method in the claim 5 to 12, wherein pawpaw emulsion lipase is about 1 with the ratio of the raw material that contains glyceryl ester and/or free fatty acids: 10w/w is to about 1: 30w/w.

14. method according to claim 13, wherein said ratio is about 1: 20w/w.

15., wherein produce described being reflected at of the described first alkyl fatty acid ester mixture and to about 70 ℃ temperature, carry out from about 30 ℃ according to each described method in the claim 2 to 14.

16. method according to claim 15, wherein said being reflected under about 50 ℃ temperature carried out.

17. according to each described method in the claim 2 to 16, the described reaction of wherein producing the described first alkyl fatty acid ester mixture continues from about 30 minutes to about 90 minutes time durations.

18. method according to claim 17, wherein said reaction continues about 60 minutes time durations.

19., further comprise the described first alkyl fatty acid ester mixture separated from solid material according to each described method in the claim 2 to 18.

20. method according to claim 19 is wherein separated the described first alkyl fatty acid ester mixture by centrifugal method from solid material.

21. according to each described method in the aforementioned claim, wherein said acid catalyst is a mineral acid.

22. method according to claim 21, wherein said mineral acid is a sulfonic acid.

23. according to each described method in the claim 2 to 22, described being reflected under the reactive distillation condition that wherein produces the described second alkyl fatty acid mixture carried out.

24. method according to claim 23, wherein said being reflected under the successive reactive distillation condition carried out.

25., wherein saidly be reflected at about 110 ℃ and carry out to about 180 ℃ temperature according to claim 23 or 24 described methods.

26. method according to claim 25 wherein saidly is reflected at about 125 ℃ and carries out to about 165 ℃ temperature.

27., wherein return to described reaction mixture from the unreacted lower aliphatic alcohols that described reaction distillation goes out according to each described method in the claim 23 to 26.

28. according to each described method in the claim 23 to 27, the wherein said second alkyl fatty acid ester mixture distills from described reaction mixture.

29. method according to claim 28 is wherein handled the described second alkyl fatty acid ester mixture that distills out to remove unreacted glycerine.

30. method according to claim 29, wherein said processing comprises gravity separation.

31. according to each described method in the claim 2 to 30, the pH regulator of the wherein said second alkyl fatty acid ester mixture is extremely between about 6 and about 8.

32. method according to claim 31, the pH regulator of the wherein said second alkyl fatty acid ester mixture is to about 7.

33. according to claim 31 or 32 described methods, wherein the medicament that is selected from the group of being formed with potassium hydroxide, sodium hydroxide, magnesium hydroxide, ammonia and calcium hydroxide by interpolation is regulated the pH of the described second alkyl fatty acid ester mixture.

34. method according to claim 33 is wherein regulated the pH of the described second alkyl fatty acid ester mixture by adding magnesium hydroxide.

35., wherein the described second alkyl fatty acid ester mixture is filtered to remove suspended solids according to each described method in the claim 2 to 34.

36., wherein handle the described second alkyl fatty acid ester mixture with filtering medium according to each described method in the claim 2 to 35.

37. method according to claim 36, wherein said filtering medium is selected from the group of being formed with diatomite, gac and silicate.

38. according to the described method of claim 37, wherein said silicate is selected from the group of being formed with silico-aluminate and magnesosilicate.

39. according to the described method of claim 38, wherein said silicate is magnesosilicate.

40. according to each described method in the claim 36 to 39, wherein by mechanical filter with described filtering medium from the described second alkyl fatty esters mixture separation.

41., further comprise according to each described method in the claim 2 to 40;

Make the reaction of Rice pollard oil and lower aliphatic alcohols to form the Rice pollard oil ester mixture under the situation of methylsulfonic acid existing;

Described Rice pollard oil ester mixture is mixed the alkyl fatty acid ester mixture that is suitable for use as fuel with formation mutually with the described second alkyl fatty acid ester mixture.

42. according to the described method of claim 41, wherein said lower aliphatic alcohols is selected from one or more in the group of being formed with methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, sec-butyl alcohol and the trimethyl carbinol.

43. according to the described method of claim 42, wherein said lower aliphatic alcohols is a propyl carbinol.

44. according to the described method of claim 43, wherein said propyl carbinol is by forming producing the glycerine that forms during the described second alkyl fatty acid mixture and the enzymic hydrolysis of soap mixture.

45. according to each described method in the claim 36 to 39, wherein said Rice pollard oil ester mixture with separate from solid material before the described second alkyl fatty acid mixture mixes.

46. according to the described method of claim 45, wherein said Rice pollard oil ester mixture separates from described solid material by centrifugal method.

47. according to each described method in the claim 41 to 46, wherein propyl carbinol is about 1 with the ratio of Rice pollard oil: 3.5w/w.

48. according to each described method in the claim 41 to 42, wherein the ratio of propyl carbinol and Rice pollard oil is about 1 in the reaction mixture of beginning: 3w/w to 1: 4w/w.

49. according to the described method of claim 48, wherein propyl carbinol is about 1 with the ratio of Rice pollard oil: 3.5w/w.

50. according to each described method in the claim 41 to 49, wherein the ratio of methylsulfonic acid and propyl carbinol is about 1 in the reaction mixture of beginning: 40w/w is to about 1: 50w/w.

51. according to the described method of claim 50, wherein methylsulfonic acid is about 1 with the ratio of propyl carbinol: 40w/w is to about 1: 50w/w.

52. alkyl fatty acid ester mixture according to each described method preparation in the claim 1 to 52.

53. biodiesel fuel according to each described method preparation in the claim 1 to 52.

54. according to the described biodiesel fuel of claim 53, the gelation temperature of wherein said fuel is between about 0 ℃ and about 10 ℃.

55. a biodiesel fuel, it is stable basically to oxidation in during at least ten two months under envrionment conditions.

56. system that is used for implementing as each described method of claim 1 to 51.

57. it is described and in fact as in conjunction with the illustrated method of example according to claim 1.