CN100569914C - A kind of method of utilizing producing biodiesel from high acid number grease - Google Patents

Abstract

The invention discloses a kind of novel method of utilizing producing biodiesel from high acid number grease such as peanut oil tankage and sewer oil, belong to waste grease production biodiesel technology field, it is characterized in that adopting two-step reaction that waste grease is converted into biofuel, the free fatty acids that promptly utilizes the bigger liquid tin tetrachloride of density to do in catalyzer and the waste grease earlier carries out pre-esterification reactor, to reduce greasy acid number, remove the glycerine of catalyzer and production is centrifugal then, will remain the direct transesterification generation of grease biofuel with KOH again.The invention has the advantages that to be suitable for various waste greases, pre-catalyst for esterification tin tetrachloride is a liquid, can make things convenient for centrifugal going out, do not influence follow-up transesterification, and the reaction conditions gentleness, the bio-diesel yield height, good product quality is applicable to large-scale industrial production.

Description

A kind of method of utilizing producing biodiesel from high acid number grease

Technical field

The present invention relates to a kind of novel method of utilizing producing biodiesel from high acid number grease such as peanut oil tankage, sewer oil, belong to waste grease production biodiesel technology.Be exactly specifically the different waste grease in various sources under tin tetrachloride and KOH catalyst action, prepare biofuel by pre-esterification of two-step approach and esterification.

Background technology

Biofuel is to utilize the produced New-type fuels that can substitute the clean and safe of petrifaction diesel of renewable resources such as Vegetable oil lipoprotein or animal grease.Main component is that the saturated unsaturated fatty acidss of long-chain such as Palmiticacid, stearic acid, oleic acid, linolic acid are with methyl alcohol or the formed ester compound of ethanol.Characteristics such as that biofuel has is renewable, be easy to biological degradation, the discharging of Air thing is low, greenhouse gas emission is low.Biofuel and petrifaction diesel have close performance.And its impayable superiority is arranged: (1) has good environmental protection characteristic.(2) has good low-temperature engine starting performance.(3) has lubricity preferably.(4) has good safety performance.(5) has good combustionproperty.(6) has renewable performance.(7) need not to change diesel engine, can directly add use, need not to add in addition bunkering facilities, storage facilities and personnel's special technique training simultaneously.(8) biofuel is in harmonious proportion with certain proportion and petrifaction diesel and uses, and can reduce oil consumption, improve dynamic property, and reduce tail gas pollution.The production biofuel has great importance to solving ecocrisis and energy dilemma.

China is the country that oil resource relatively lacks, and China's import grease was more than 1,000 ten thousand tons in 2006, accounted for more than 40% of China's grease consumption, therefore utilizes polished fat's production biofuel not have economic implications in China.Acid number is a high-acid value grease greater than 5 grease, belongs to the grease that anorexia is used, and the contour acid number grease of plant oil leftover and discarded food oils is the main raw material of current China production biofuel.

The production method of biofuel mainly contains chemical method and enzyme process, enzyme process is because catalyzer price height, the catalysis time is long, reasons such as the easy inactivation of catalyzer, also have a segment distance from industrialization: chemical method comprises base catalysis and acid catalysis, base catalysis efficient height, low for equipment requirements, but this technology is higher to ingredient requirement, for the higher waste grease (plant oil leftover of free fatty acid content, the trench wet goods) then can not directly use, acid catalysis is low to ingredient requirement, but have the equipment corrosion height, long reaction time, shortcoming such as low and byproduct glycerine purity difference of bio-diesel yield.

The two-step catalysis method can be converted into biofuel with the grease of high acid value, has solved the acid system transformation efficiency simultaneously and has hanged down and the drawback of alkaline process to the ingredient requirement strictness, is fit to the current national conditions with waste grease production biofuel of China.But need to solve the removal problem of acid in the first step catalytic process.

Summary of the invention

The objective of the invention is to disclose a kind of novel method of utilizing peanut oil tankage and this class preparing biological diesel fuel by high-acid-value grease of trench wet goods, to solve the problems referred to above that chemical method preparation life diesel oil exists.

The present invention adopts following technical scheme: a kind of method of utilizing producing biodiesel from high acid number grease, it is characterized in that its transesterification reaction is to adopt earlier pre-fat reduction acid value of oil and fat, and undertaken by base catalysis again that the two-step approach of esterification carries out.

More satisfactory is that its concrete production process comprises the steps:

(1), under the stannic chloride catalyst effect, carries out pre-esterification reactor with various discarded high-acid value greases and methanol mixed; Temperature of reaction is 58-63 ℃, and tin tetrachloride accounts for the heavy 2%-3% of grease, and pure oil quality ratio is 1: 2-1: 3, and the reaction times is 2-3h

(2) with step (1) gained reactant standing demix, centrifugal catalyzer and the glycerine that removes sub-cloud;

(3), catalyzer KOH is dissolved in methyl alcohol after, and the residue grease that reclaims in the step (2) behind the methyl alcohol joins in the reactor together, in temperature of reaction is 58-63 ℃, KOH accounts for the heavy 1%-1.2% of residue grease, alcohol oil quality ratio is 1: 5-1: 8, and the reaction times is to carry out esterification under the 40-60min;

(4), with step (3) gained reactant static layering, the upper strata contains biofuel and methyl alcohol, lower floor contains glycerine, KOH, small amounts of soap and methyl alcohol;

(5), supernatant liquid is reclaimed methyl alcohol through methanol distillation column, to clarification of water, the supernatant liquid dehydration is obtained the biofuel product with the water washing that is higher than 5 ℃-10 ℃ of oil temperature.

The invention provides a kind of novel method of production of biodiesel, utilize two-step approach production biofuel, the pre-esterification of the first step can effectively reduce the acid number of waste grease, does not influence the second step base catalyzed reactions, particularly with tin tetrachloride as easy centrifugal the removing of pre-fat catalyzer.Present method both can use peanut oil tankage, the various waste greases of trench wet goods to be raw material, can accelerate the production rate of biofuel simultaneously again, obviously shortened the reaction times, and had improved the yield of biofuel, had improved the benefit of enterprise.

Embodiment

The invention will be further described below in conjunction with specific embodiment, to help understanding content of the present invention.

Embodiment 1,

Take by weighing 100g peanut oil tankage (acid number is 150) and put into Erlenmeyer flask, add 40g methyl alcohol and 2 gram tin tetrachloride, above-mentioned various materials are mixed in Erlenmeyer flask carry out pre-esterification reactor; Temperature of reaction is 60 ℃, and the reaction times is 2h.Reaction finishes back standing demix 20min, centrifugal catalyzer and the glycerine that removes sub-cloud.Be dissolved in catalyzer KOH behind the methyl alcohol and the residue grease joins together and carries out esterification in the reactor, temperature of reaction is 60 ℃, KOH account for the residue grease heavy 1.2%, pure oil quality ratio is 1: 8, the reaction times is 50min.Reaction finishes back standing demix 60min, and the upper strata is mainly fatty acid methyl ester and small amount of methanol, and lower floor is mainly glycerine, KOH, small amount of methanol.After the upper strata product reclaimed methyl alcohol by methyl alcohol distillation tower vacuum,, to get upper oil phase and remove moisture by thin-film evaporator through vacuum distilling and obtain biofuel elaboration 94.5 grams with 15ml65 ℃ hot wash, centrifugal layering. the reaction total yield is 94.5%.

Embodiment 2,

Take by weighing 100g sewer oil (acid number is 90) and put into Erlenmeyer flask, add 50g methyl alcohol and 3 gram tin tetrachloride, above-mentioned various materials are mixed in Erlenmeyer flask carry out pre-esterification reactor; Temperature of reaction is 60 ℃, and the reaction times is 3h.Reaction finishes back standing demix 20min, centrifugal catalyzer and the glycerine that removes sub-cloud.Be dissolved in catalyzer KOH behind the methyl alcohol and the residue grease joins together and carries out esterification in the reactor, temperature of reaction is 60 ℃, KOH account for the residue grease heavy 1.2%, pure oil quality ratio is 1: 8, the reaction times is 50min.Reaction finishes back standing demix 60min, and the upper strata is mainly fatty acid methyl ester and small amount of methanol, and lower floor is mainly glycerine, KOH, small amount of methanol.After the upper strata product reclaimed methyl alcohol by methyl alcohol distillation tower vacuum,, to get upper oil phase and remove moisture by thin-film evaporator through vacuum distilling and obtain biofuel elaboration 96.7 grams with 15ml65 ℃ hot wash, centrifugal layering. the reaction total yield is 96.7%.

Embodiment 3,

Take by weighing 200g frying oil (acid number is 30) and put into Erlenmeyer flask, add 80g methyl alcohol and 4 gram tin tetrachloride, above-mentioned various materials are mixed in Erlenmeyer flask carry out pre-esterification reactor; Temperature of reaction is 60 ℃, and the reaction times is 2h.Reaction finishes back standing demix 20min, centrifugal catalyzer and the glycerine that removes sub-cloud.Be dissolved in catalyzer KOH behind the methyl alcohol and the residue grease joins together and carries out esterification in the reactor, temperature of reaction is 60 ℃, KOH account for the residue grease heavy 1.2%, pure oil quality ratio is 1: 8, the reaction times is 50min.Reaction finishes back standing demix 60min, and the upper strata is mainly fatty acid methyl ester and small amount of methanol, and lower floor is mainly glycerine, KOH, small amount of methanol.After the upper strata product reclaimed methyl alcohol by methyl alcohol distillation tower vacuum,, to get upper oil phase and remove moisture by thin-film evaporator through vacuum distilling and obtain biofuel elaboration 194.4 grams with 15ml65 ℃ hot wash, centrifugal layering. the reaction total yield is 97.2%.

Embodiment 4,

Take by weighing 200g frying oil (acid number is 30) and put into Erlenmeyer flask, add 100g methyl alcohol and 6 gram tin tetrachloride, above-mentioned various materials are mixed in Erlenmeyer flask carry out pre-esterification reactor; Temperature of reaction is 60 ℃, and the reaction times is 3h.Reaction finishes back standing demix 20min, centrifugal catalyzer and the glycerine that removes sub-cloud.Be dissolved in catalyzer KOH behind the methyl alcohol and the residue grease joins together and carries out esterification in the reactor, temperature of reaction is 60 ℃, KOH account for the residue grease heavy 1.1%, pure oil quality ratio is 1: 5, the reaction times is 50min.Reaction finishes back standing demix 60min, and the upper strata is mainly fatty acid methyl ester and small amount of methanol, and lower floor is mainly glycerine, KOH, small amount of methanol.After the upper strata product reclaimed methyl alcohol by methyl alcohol distillation tower vacuum, with 15ml65 ℃ hot wash, centrifugal layering, get upper oil phase and remove moisture by thin-film evaporator through vacuum distilling and obtain biofuel elaboration 196 grams, the reaction total yield is 98%.

Claims (2)

1, a kind of method of utilizing producing biodiesel from high acid number grease is characterized in that: its transesterification reaction is to adopt earlier pre-fat reduction acid value of oil and fat, is undertaken by base catalysis that the two-step approach of esterification carries out again; Comprise the steps:

(1), under the stannic chloride catalyst effect, carries out pre-esterification reactor with various discarded high-acid value greases and methanol mixed; Temperature of reaction is 58-63 ℃, and tin tetrachloride accounts for the heavy 2%-3% of grease, and pure oil quality ratio is 1: 2-1: 3, and the reaction times is 2-3h;

(2) with step (1) gained reactant standing demix, centrifugal catalyzer and the glycerine that removes sub-cloud;

(3), catalyzer KOH is dissolved in methyl alcohol after, and the residue grease that reclaims in the step (2) behind the methyl alcohol joins in the reactor together, in temperature of reaction is 58-63 ℃, KOH accounts for the heavy 1%-1.2% of residue grease, alcohol oil quality ratio is 1: 5-1: 8, and the reaction times is to carry out esterification under the 40-60min condition;

(4), with step (3) gained reactant standing demix, the upper strata contains biofuel and methyl alcohol, lower floor contains glycerine, KOH, small amounts of soap and methyl alcohol;

(5), supernatant liquid is reclaimed methyl alcohol through methanol distillation column, to clarification of water, the supernatant liquid dehydration is obtained the biofuel product with the water washing that is higher than 5 ℃-10 ℃ of oil temperature.

2, the method for utilizing producing biodiesel from high acid number grease as claimed in claim 1 is characterized in that: the dehydration in the described step (5) is for dewatering with thin-film evaporator vacuum distilling.