CN101033406A

CN101033406A - Method of preparing biological diesel oil catalyzed by silicate

Info

Publication number: CN101033406A
Application number: CNA200710011068XA
Authority: CN
Inventors: 修志龙; 郭峰; 彭振刚
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2007-04-20
Filing date: 2007-04-20
Publication date: 2007-09-12
Anticipated expiration: 2027-04-20
Also published as: CN100523130C

Abstract

This invention relates to a method for preparing bio-diesel oil by catalyzing silicate characterizing in applyingNa2SO3, K2SO3 and Na2K2SO3 as the catalysts to catalyze grease to react with short chain alcohol to prepare bio-diesel oil, which can use 1-5% catalyst of oil weight to catalyze grease with moisture as high as 2%, and the mol ratio of alcohol and oil is 4-12:1reacting for 30-120min under 60-90deg.C to get 99.8% conversion and 96% yield.

Description

A kind of method of preparing biological diesel oil catalyzed by silicate

Technical field

The invention belongs to the environmental friendliness technical field of new energy production, relate to a class new catalyst, specially refer to a kind of method of preparing biological diesel oil catalyzed by silicate.

Background technology

Along with the minimizing gradually of world oil reserves, various countries try to explore to develop alternative fuel and renewable energy source from the angle of environment protection and resource strategy.Because the main component of biofuel is a fatty acid methyl ester, being with renewable resources---animal-plant oil is that raw material is made through esterification or transesterification, have the performance close with petroleum diesel, and not sulfur-bearing and aromatic hydrocarbons substantially, cetane value is up to 52.9, biodegradable, nontoxic, environmental sound, and the exhaust gas emission index meets strict European III standard, the more important thing is that biofuel has recyclability, its resource can be inexhausted.Countries in the world are all in the research and development and the production of activity investment biofuel at present, and especially the America and Europe, biofuel realizes commercial applications already, and has formed sizable scale.Though China's starting is later relatively, country will develop biological liquid fuel and substitute the developing direction that oil is defined as energy industry.

The production method of biofuel mainly contains chemical method and enzyme process, is the long-chain fat acid monoester that raw material and short chain alcohol such as methyl alcohol, ethanol, propyl alcohol etc. obtain by transesterification reaction, i.e. biofuel with the animal-plant oil.As catalyzer, advantage is the reaction conditions gentleness to enzyme process with lipase, and energy consumption is low, and pure consumption is few, and glycerine reclaims easily, quality product higher (a kind of method of production of biological diesel oil by fixed enzyme, CN1818026).But the easy inactivation of lipase, and exist speed of reaction slow, shortcomings such as cost height are so also have a segment distance from industrial applications.Industrial method commonly used is a chemical method at present, according to the glyceride stock difference, and as acid number height, water content size etc., can corresponding selection base catalysis or acid catalysis.Acid catalyst comprises sulfuric acid, phosphoric acid, hydrochloric acid and various organic sulfonic acid, when containing higher free fatty acid and water in the raw material, the acid catalysiss that adopt more, relevant patent have preparing biological diesel oil by esterifying, ester interchanging greases in high acid number method (CN1760335), utilize high acid value animal-plant oil production method of bio-diesel oil (CN1556174) etc., but this method speed of reaction is low, compare with the base catalysis method and to exist the reaction times longer, and to the more high shortcoming of equipment requirements.Base-catalyzed transesterification reaction highly basic (as sodium hydroxide, potassium hydroxide etc.) commonly used, carbonate, trialkylphosphine oxide (production method of bio-diesel oil, CN1826403 such as (sodium methylate, sodium ethylates etc.); A kind of method for synthesizing biological fuel-oil, CN1850944), alkaline catalysts is low for equipment requirements, and can obtain higher transformation efficiency within a short period of time, uses more in industry.But the content of free lipid acid and water should be low as far as possible in the base catalysis requirement glyceride stock, otherwise saponification reaction easily takes place, and after the catalyzed reaction end, catalyzer must be removed from product, and the alkaline waste water of generation must be handled, otherwise causes secondary pollution.Recovery problem at catalyzer, many scientific research personnel turn to solid catalyst with sight, (a kind of solid acid, base catalysis prepare method of bio-diesel oil though solid acid catalyst can reclaiming, CN1580190), but preparation is complicated, catalytic efficiency is not high, and solid acid surface SO42-easily loses, and can't reach application requiring.Solid base catalyst has overcome the used even phase catalyst separation difficulty of existing transesterification reaction, catalyzer is difficult for the regenerated defective, reduced the operating unit that separates and wash simultaneously, disadvantageous effect (a kind of solid base catalyst and preparation method and application, the CN1680514 of saponification reaction have been eliminated; Adopt the solid alkali legal system to be equipped with method of bio-diesel oil, CN1664072; A kind of production method of biofuel, CN1861749).Catalyzer can recycle, and adopts precipitation agent and flocculation agent way of combining, simply removes the impurity in the coarse biodiesel efficiently, obtain the fine biofuel (a kind of technology of utilizing solid alkali to prepare biofuel, CN1896182).So, seek low price, the catalytic activity height, recyclable, recycling, easily regeneration, energy consumption is low, pollutes little catalyzer and is at present and future biodiesel manufacture research direction.

Summary of the invention

The purpose of this invention is to provide a kind of silicate catalyst and prepare method of bio-diesel oil, this class new catalyst is silicates such as water glass, potassium silicate, sodium-potassium silicate, but their catalysis animal-plant oil and short chain alcohol reaction production biofuel, this method power consumption is few, reduce and pollute, solved liquid alkali catalyst commonly used and be difficult to recovery, recycling and regenerated problem.

The step that realizes the inventive method is as follows:

(A) mixture with grease or grease and organic solvent joins in the reactor, add silicate catalyst and methyl alcohol or ethanol again, alcohol oil rate is 4～12: 1 (mol ratio), at 60～90 ℃ of following stirring reaction 30～120min, standing demix, upper strata promptly obtain rough biofuel;

(B) rough biofuel is reclaimed alcohol (or organic solvent), obtain the biofuel highly finished product through rectification under vacuum then; To descend phase glycerine and catalyst separating, reclaim standby;

(C) the recycling catalyzer that reclaims, according to steps A, the described method of B prepares biofuel;

(D) with the catalyst recovery of step C recycling several times, after the NaOH of adding 0.2～1.5mol/L or the KOH regeneration, can continue according to steps A, B prepares biofuel.

In steps A, used grease is one or both in soybean oil, rapeseed oil, plam oil, Viscotrol C, tung oil, the deacidification trench wet goods; Organic solvent is sherwood oil, normal hexane, hexanaphthene or acetone; Described short chain alcohol is methyl alcohol, ethanol, propyl alcohol, Virahol or butanols.

Effect of the present invention and benefit are new catalyst and greases (or mixture of grease and organic solvent) and short chain alcohol reaction production biofuel such as employing water glass, the catalyzer of gained can reuse in the steps A, and can use certain density strong base solution such as NaOH or KOH to realize the regeneration of catalyzer, reduce production cost.Catalyzer that the present invention adopts is cheap, and is easily separated, can reuse, renewable, the production process non-pollution discharge, and postprocessing working procedures is simple.Reaction is at room temperature left standstill 6～12h after finishing, and catalyzer is in settling process, can adsorb pigment, free glycerol in the biofuel, both improve the color and luster of product, removed free glycerol residual in the grease again, greatly improved the quality of biofuel product.In addition, this catalyzer also has good katalysis to water content up to 2% glyceride stock, thereby simplifies the preprocessing process of glyceride stock, is suitable for large-scale industrial production.

Embodiment

Be described in detail the specific embodiment of the present invention below in conjunction with technical scheme.

Embodiment one

In reactor, add soybean oil 30g, add methyl alcohol 8ml again, water glass 0.3g, 60 ℃, 200r/min stirring reaction 60min measures the biofuel product with gas-chromatography (GC) method, and transformation efficiency is 99.8%.The upper strata product reclaimed methyl alcohol after vacuum distilling obtains biofuel highly finished product reaction total yield is 96%.

Embodiment two

Add soybean oil 30g in reactor, water 0.3g (1%) adds methyl alcohol 8ml again, water glass 0.3g, and 60 ℃, 200r/min stirring reaction 60min, GC measures the biofuel product, and transformation efficiency is 94.8%.

Embodiment three

Add soybean oil 30g in reactor, sherwood oil 33ml adds water glass 1.5g again, methyl alcohol 8ml, 60 ℃, 200r/min stirring reaction 40min.Reaction finishes standing demix, and inclining upper strata biofuel product, reclaims methyl alcohol and sherwood oil in the product of upper strata then, continues mutually down to add the 30g soybean oil, and 33ml reclaims sherwood oil, and 8ml reclaims methyl alcohol, continues reaction 40min.Catalyzer recycling 3 times, gained biofuel transformation efficiency is respectively 96.1%, 95.4%, 86.7%.

Embodiment four

Take by weighing and reuse 3 times water glass 1.8g, dissolve with 20mL 1mol/L NaOH, in 100 ℃ of seasoninies, 500 ℃ of roasting 3h take by weighing 0.6g regeneration water glass with 8ml methyl alcohol mixing, join in the reactor that fills the 30g soybean oil, at 60 ℃, 200r/min stirring reaction 60min, GC measures the biofuel product, and transformation efficiency is 92.4%.

Embodiment five

In the thick rapeseed oil of 30g, add 1% vitriol oil, methyl alcohol 6ml, 80 ℃ of stirring reaction 2h, acid number is reduced to the 1.07mgKOH/g sample, leaves standstill AUTOMATIC ZONING, removes down phase.Then temperature is transferred to 60 ℃, add methyl alcohol 8ml, water glass 0.3g, 200r/min stirring reaction 60min, GC measures the biofuel product, and transformation efficiency is 97.8%.

Claims

1. method of utilizing preparing biological diesel oil catalyzed by silicate, its feature may further comprise the steps:

(A) mixture with grease or grease and organic solvent joins in the reactor, adds silicate catalyst and short chain alcohol such as methyl alcohol and ethanol again, and molar ratio of methanol to oil is 4～12: 1 at 60～90 ℃ of following stirring reaction 30～120min, obtains rough biofuel;

(B) with steps A gained reactant standing demix, get and reclaim alcohol mutually, obtain the biofuel highly finished product through vacuum distilling then; To descend phase glycerine and catalyst separating, catalyst recovery is standby;

(C) the recycling catalyzer that reclaims prepares biofuel according to the described method of steps A;

(D) with the catalyst recovery after the active decline of step C recycling, add certain density strong base solution such as NaOH or KOH regeneration, use regenerated catalyst to prepare biofuel according to steps A.

2. a kind of method of utilizing preparing biological diesel oil catalyzed by silicate according to claim 1 is characterized in that catalyzer that steps A is used is water glass, potassium silicate or sodium-potassium silicate, and catalyst levels is that oil is heavy by 1～5%; Grease is soybean oil, rapeseed oil, Oleum Gossypii semen, plam oil, Viscotrol C, tung oil or deacidification sewer oil, and the grease water content is 0～2%; Organic solvent is sherwood oil, normal hexane, hexanaphthene or acetone; Use the mixture of grease or grease and organic solvent; Short chain alcohol is methyl alcohol, ethanol, propyl alcohol, Virahol or butanols, and molar ratio of methanol to oil is 4～12: 1.

3. a kind of method of utilizing preparing biological diesel oil catalyzed by silicate according to claim 1 is characterized in that it is 6～12h that step B leaves standstill required time.

4. a kind of method of utilizing preparing biological diesel oil catalyzed by silicate according to claim 1 is characterized in that, step C catalyzer recycling 3～5 times.

5. a kind of method of utilizing preparing biological diesel oil catalyzed by silicate according to claim 1 is characterized in that, step D uses 0.2～1.5mol/L NaOH or KOH catalyst-solvent, 80～150 ℃ of seasoninies, 300～800 ℃ of roasting 1～3h activating and regeneratings.