CN101311247B

CN101311247B - Process for strengtheningly and rapidly preparing biodiesel by solvent

Info

Publication number: CN101311247B
Application number: CN2007100995043A
Authority: CN
Inventors: 王玉春; 曾建立; 王晓东; 赵兵; 袁晓凡; 夏禹杰
Original assignee: Institute of Process Engineering of CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 2007-05-23
Filing date: 2007-05-23
Publication date: 2012-11-21
Anticipated expiration: 2027-05-23
Also published as: CN101311247A

Abstract

The invention relates to a production method for rapidly preparing biodiesel by using a solvent for strengthening, which is characterized in that double-ether substances is introduced as a co-solvent so as to lead triglyceride and lower alcohol to form a homogeneous reaction system, augment reaction interface, accelerate reaction speed and reduce mechanical agitation. The co-solvent has the advantages of moderate boiling point, convenient recovery, high safety, and the like, and is applicable to industrial production.

Description

A kind of method of strengtheningly and rapidly preparing biodiesel by solvent

Technical field

The present invention relates to field of renewable energy technology, refer to that specifically the novel cosolvent of a kind of introducing prepares method of bio-diesel oil fast.

Background technology

Along with fossil energy environmental problem day by day exhausted and that cause owing to the use fossil energy becomes increasingly conspicuous, countries in the world have all turned one's attention to renewable energy source.Wherein, Have the fuel performance similar by reproducible animal-plant oil through the lipid acid esters of gallic acid material that transesterification reaction generates with petrifaction diesel; Can perhaps with after petrifaction diesel mixes directly be used for existing diesel motor separately, so this type fatty acid ester material also is known as " biofuel ".

Greasy staple is a tri-glyceride, and promptly three molecule longer chain fatty acids and a part glycerine link together through ester bond.Transesterification reaction takes place under certain condition in tri-glyceride and lower alcohol, and promptly the longer chain fatty acid on the glycerine is transferred on the methyl alcohol, just can become fatty acid methyl ester (biofuel) by dirt.This reaction can be passed through acid catalysis, base catalysis, enzyme catalysis or under super critical condition, carry out.Advantages such as it has been exactly base catalysis technology that industry is at present gone up most widely used, reacts very fast consuming time few because this technology has, and facility investment is low.Use water soluble alkali catalysis often only to need tens minutes just can reach the transformation efficiency that just can reach that acid catalysis and enzyme catalysis need several hrs to dozens of minutes.For example 45 ℃, molar ratio of methanol to oil 6: 1, do under the condition of catalyzer with the Pottasium Hydroxide that accounts for VT 18 quality 1.1%; The transformation efficiency of tri-glyceride is that 98.33% (Linxi is flat for Wu Guoying, Wu Miaoxin behind the reaction 60min; Zhang Youchun; Liu Yong. vegetables oil prepares biofuel. Jiangsu Petrochemical Engineering College journal, 2002,14 (3): 8-11).

With respect to other technology; Base catalysis is than technology faster, but this reaction time consumption is still long, also has the space of shortening; Major cause is that strong polar alkaline catalysts only is dissolved in the lower alcohol of polar solvent; And be insoluble to tri-glyceride, and tri-glyceride and methyl alcohol and ethanol do not dissolve each other, so reaction can only take place at two-phase interface.If can introduce the inertia cosolvent, improve the pure oil phase ability of separating of dissolving each other, even form single homogeneous reaction system, will increase effective catalytic surface greatly, improve speed of response.For example just adopt cyclic ethers (like THF, 1,4-dioxan) and monoether (like MTBE, diethyl ether, DIPE) to make solvent in the Canadian Patent 2131654, shortened the reaction times.But there are some problems in cyclic ethers and monoether in practical application; At first from their boiling point (seeing table one), the boiling point of diethyl ether and tertbutyl ether is also lower than methyl alcohol, if as cosolvent; Temperature of reaction must be carried out at low temperatures; Reducing solvent evaporates, and low temperature is unfavorable for the grease transesterification reaction, and the boiling point of organic solvent and flash-point low more use also just more dangerous; 1, the boiling point of 4-dioxan is too high, and energy consumption is bigger during recovery, and differs too little with the boiling point of water and also be not suitable for as cosolvent; The moderate boiling point of having only THF and DIPE; But because the boiling point of they and methyl alcohol is too approaching; When reclaiming, can only be distilled out together, they be measured accurately separately and just are not easy to have confirmed like this, wait to add when using how much amount just is difficult to confirm next time.In addition, THF should not be that it contacts with air and is easy to generate dangerous superoxide as another reason of cosolvent.

The boiling point of table one cyclic ethers and monoether

Cosolvent	Diethyl ether	MTBE	THF	DIPE	1, the 4-dioxan
						Boiling point (℃)	34.5	55	66	68	101

Therefore seek and be easy to recovery, and the higher cosolvent of safety performance has great importance for the industrial production biofuel.Bis ether class material such as Methylal(dimethoxymethane), 1,2-glycol dimethyl ether, 2; The 2-Propanal dimethyl acetal, methylene diethyl ether, 1; The 1-diethoxyethane, 1,2-diethoxyethane etc. also has lower alcohol and the codissolved ability of grease (accompanying drawing 1 has shown several kinds of bis ethers and methyl alcohol, the three phase diagram of grease under 25 ℃) of promoting; All can be used as cosolvent, be used for the biodiesel manufacture process intensification.Table two has been listed their boiling point, and wherein 1, the 2-glycol dimethyl ether, 2, the 2-Propanal dimethyl acetal, the boiling point of methylene diethyl ether and methyl alcohol differ about 20 ℃, are easy to separate with methyl alcohol, are suitable cosolvent.

The boiling point of table two bis ether

Summary of the invention

Problem to be solved by this invention be exactly to existing cosolvent in practical application problem and provide one type of novel cosolvent to be used for biofuel to prepare fast, this method may further comprise the steps:

(1) confirm that through the phasor of cosolvent/lower alcohol/tri-glyceride cosolvent reaches the amount that cosolvent effect needs,

(2) preparation contains the alcoholic solution of catalyzer,

(3) add tri-glyceride, the low-alcohol solution that contains catalyzer and cosolvent in proportion to reactor drum,

(4) control reaction conditions.

Biodiesel oil preparing process provided by the invention, employed cosolvent are bis ether class material, are selected from Methylal(dimethoxymethane), 1, the 2-glycol dimethyl ether; 2,2-Propanal dimethyl acetal, methylene diethyl ether, 1; The 1-diethoxyethane, 1, one or more in the 2-diethoxyethane.

Biodiesel oil preparing process provided by the invention; Employed tri-glyceride is animal-plant oil or microbial oil and their mixture, is selected from Semen Maydis oil, Oleum Gossypii semen, Trisun Oil R 80, sweet oil, plam oil, palm-kernel oil, peanut oil, soya-bean oil, oleum lini, tung oil, Thistle oil, rapeseed oil, til, perilla oil, babassu oil, fish oil, Viscotrol C, Chinese vegetable tallow, jatropha oil, little algae oil, bacterium is oily, mould is oily, Oleum Cocois, butter, lard, chicken fat, duck oil.

Biodiesel oil preparing process provided by the invention, employed lower alcohol is selected from one or more in methyl alcohol, ethanol, propyl alcohol, the butanols.

Biodiesel oil preparing process provided by the invention, the mol ratio of lower alcohol and tri-glyceride are 3: 1～30: 1.

Biodiesel oil preparing process provided by the invention, employed catalyzer are Pottasium Hydroxide or sodium hydroxide, and it is heavy by 0.5～2.5% that catalyzer accounts for oil.

Biodiesel oil preparing process provided by the invention is reflected under the normal pressure and carries out.

Biodiesel oil preparing process provided by the invention, temperature of reaction are controlled between 25～65 ℃.

The invention has the beneficial effects as follows:

(1) grease and methyl alcohol are dissolved altogether, less mechanical stirring has been accelerated reaction process greatly;

(2) novel cosolvent boiling point is higher, uses saferly, also is easy to separate with methyl alcohol;

(3) reduce the catalyzer partial concn, reduced saponification reaction.

Description of drawings

Fig. 1: some bis ethers and methyl alcohol and the grease three phase diagram under 25 ℃

Each components contents variation diagram among Fig. 2: the embodiment 1, wherein FAME is a fatty acid methyl ester, MG fatty acid mono glycidol, DG are the lipid acid double glyceride, the TG fatty acid glyceryl ester

Embodiment

Embodiment one

With taking by weighing the 55g Trisun Oil R 80 in the there-necked flask, claim that again Pottasium Hydroxide 0.825g is dissolved in 15.0ml methyl alcohol, the consumption of methylene diethyl ether is 31.0ml, three kinds of liquid adding beginning to react timing.45 ℃ of heating in water bath controlled temperature, mechanical stirring rotating speed 400r/min stops to stir behind the stirring 15s.Timing sampling is seen Fig. 2 through each component concentration variation of gas chromatographic analysis, and the grease transformation efficiency reaches 94.3% in the time of 5 minutes, and methyl esters content is 93.4%.

The saponified grease taking place account for 0.27% of weight, does not use cosolvent that 1.4% grease generation saponification reaction is arranged under the same terms.

Embodiment two

Be dissolved in 15.0ml methyl alcohol with Pottasium Hydroxide 1.210g, together with 31ml 1, the 2-glycol dimethyl ether is poured the there-necked flask that fills the 55g Trisun Oil R 80 into, 45 ℃ of control reaction temperature, and mixing speed 400r/min stops to stir behind the stirring 15s.Timing sampling, through gas chromatographic analysis, methyl esters content is 96.4% in the time of 3 minutes.

Embodiment three

Be dissolved in 31.0ml methyl alcohol with Pottasium Hydroxide 0.275g, together with 55.1ml2, the 2-Propanal dimethyl acetal is poured the there-necked flask that fills the 55g Trisun Oil R 80 into, 45 ℃ of control reaction temperature, and mixing speed 400r/min stops to stir behind the stirring 15s.Timing sampling, through gas chromatographic analysis, methyl esters content is 94.2% in the time of 7 minutes.

Embodiment four

Be dissolved in 7.5ml methyl alcohol with Pottasium Hydroxide 0.825g, pour the there-necked flask that fills the 55g Trisun Oil R 80 into together with the 26.0ml methylene diethyl ether, 65 ℃ of control reaction temperature, mixing speed 400r/min stops to stir behind the stirring 15s.Timing sampling, through gas chromatographic analysis, methyl esters content is 93.2% in the time of 5 minutes.

Embodiment five

Be dissolved in 7.5ml methyl alcohol with Pottasium Hydroxide 1.20g, pour the there-necked flask that fills the 55g Trisun Oil R 80 into together with the 26.0ml methylene diethyl ether, 65 ℃ of control reaction temperature, mixing speed 400r/min stops to stir behind the stirring 15s.Timing sampling, through gas chromatographic analysis, methyl esters content is 96.2% in the time of 5 minutes.

Embodiment six

Be dissolved in 15.0ml methyl alcohol with Pottasium Hydroxide 1.20g, pour the there-necked flask that fills the 55g Trisun Oil R 80 into together with the 31.0ml methylene diethyl ether, 25 ℃ of control reaction temperature, mixing speed 400r/min stops to stir behind the stirring 15s.Timing sampling, through gas chromatographic analysis, methyl esters content is 96.8% in the time of 5 minutes.

Claims

1. the method for a strengtheningly and rapidly preparing biodiesel by solvent is accelerated reaction process with bis ether class cosolvent, and cosolvent is easy to reclaim, and it is characterized in that this method may further comprise the steps:

(1) adds cosolvent, tri-glyceride, lower alcohol and catalyzer by a certain percentage;

(2) control condition makes glycerine and fatty ester layering mutually after reaction for some time;

(3) lower alcohol and cosolvent are reclaimed in distillation;

Wherein, said cosolvent is a bis ether class material, is selected from Methylal(dimethoxymethane), 1,2-glycol dimethyl ether, 2,2-Propanal dimethyl acetal, methylene diethyl ether, 1,1-diethoxyethane, 1, one or more in the 2-diethoxyethane; The consumption of said cosolvent calculates according to the three phase diagram of cosolvent/lower alcohol/tri-glyceride; Said tri-glyceride is animal-plant oil or microbial oil and their mixture, is selected from Semen Maydis oil, Oleum Gossypii semen, Trisun Oil R 80, sweet oil, plam oil, palm-kernel oil, peanut oil, soya-bean oil, oleum lini, tung oil, Thistle oil, rapeseed oil, til, perilla oil, babassu oil, fish oil, Viscotrol C, Chinese vegetable tallow, jatropha oil, little algae oil, bacterium is oily, mould is oily, Oleum Cocois, butter, lard, chicken fat, duck oil.

2. according to the described method of claim 1, it is characterized in that said lower alcohol is selected from one or more in methyl alcohol, ethanol, propyl alcohol, the butanols.

3. according to claim 1 or 2 described methods, it is characterized in that alcohol is 3: 1～30: 1 with the mol ratio of tri-glyceride.

4. according to the described method of claim 1, it is characterized in that catalyzer is Pottasium Hydroxide or sodium hydroxide, it is heavy by 0.5～2.5% that catalyzer accounts for oil.

5. according to the described method of claim 1, it is characterized in that, be reflected under the normal pressure and carry out.

6. according to the described method of claim 1, it is characterized in that temperature of reaction is controlled between 25～65 ℃.