Be used to prepare the load type solid body base catalyst of biodiesel
Technical field
The present invention relates to a kind of catalyst, particularly a kind of load type solid body base catalyst that is used to prepare biodiesel.
Background technology
Biodiesel is to utilize renewable material manufacturings such as vegetable fat or animal fat to be used for substituting the New-type fuel of the clean and safe of petrifaction diesel, and main component is that the long-chain of 16~18 carbon is saturated, unrighted acid is with the formed fatty acid methyl ester of methyl alcohol.Along with the enhancing of twice oil crisis that occurs last century and environmental protection consciousness, biodiesel has worldwide formed the research and development upsurge as a kind of eco-friendly renewable material new forms of energy.
Biodiesel mainly is to produce with chemical method at present.Traditional ester exchange process is to be the homogeneous phase technology of catalyst with liquid acid or alkali, the purifying products of gained and separation difficulty, and also yield is low, equipment is required high.In addition, the waste water and waste liquid of discharging in this process is brought severe contamination to environment.
Along with the reinforcement of environmental consciousness and the development of Green Chemistry, people more and more pay attention to eco-friendly catalysis new technology, and solid acid-base replaces the application study of liquid soda acid in chemical process more and more widely.Compare with liquid base, solid base have can be recycled, environmental friendliness, reaction condition gentleness, product is easy to separate, can make the serialization of reaction process process, the advantages such as production capacity of raising equipment, thereby in production of biodiesel technology, adopt the solid base heterogeneous catalysis to have more advantage than liquid base homogeneous catalysis.
Chinese patent CN1664072A (adopts the solid base legal system to be equipped with method of bio-diesel oil, 2005.9.7) discloses the employing solid base catalyst and prepared method of bio-diesel oil.This catalyst mainly is the mixture, support type alkaline earth oxide of alkalies and alkaline earth composite oxides etc., does not relate to concrete preparation process, and catalyst is short service life, and because the preparation material expensive causes the catalyst cost higher.Chinese patent CN1830550A (synthesis reaction catalyst for loading type alkali metal biodiesel oil, 2006.9.13) in solid base catalyst to prepare the technical process of biodiesel simple, catalyst reaches 90% to the catalytic transesterification rate of triglycerides, have only the part catalyst to reach 99%, as seen catalyst performance instability, product need can be met the fatty acid methyl ester of 0# diesel oil serviceability through purifying.In addition, catalysis material price height causes the catalyst cost higher.
As a whole, at present solid base catalyst is owing to reasons such as catalytic activity, preparation material and service lifes in the patent, and overall cost is than liquid base acid catalyst height, thereby restricted solid base catalyst in industrial large-scale application.
Summary of the invention
Purpose of the present invention is intended at above-mentioned problems of the prior art, a kind of load type solid body base catalyst that is used to prepare biodiesel is provided, it selects cheap porous material to make carrier, preparation process is simple, can regenerate and reuse, reduced the cost of solid base catalyst to a certain extent.
Concrete technical scheme of the present invention is as follows:
A kind of load type solid body base catalyst that is used to prepare biodiesel, characteristics are: the quality ratio by alkali metal or alkaline-earth metal soluble-salt and porous material is 0.2~0.65, with the soluble-salt aqueous solution incipient impregnation porous material of alkali metal or alkaline-earth metal, stirs and ageing, drying, calcining, gets through grinding.
Described porous material is at least a in sepiolite, kaolin, attapulgite, 3A zeolite, 4A zeolite and the 5A zeolite.
Described alkali metal is at least a in lithium, sodium, potassium, rubidium, the caesium, and alkaline-earth metal is selected from least a in magnesium, calcium, strontium, the barium.
Described stirring digestion time is 3~10h.
Described baking temperature is 100~120 ℃.
Described calcining heat is 550 ℃~850 ℃, and the time is 0.5~10h.
Described grinding particle diameter is below 100 orders.
The present invention is with alkali metal or alkaline-earth metal soluble-salt aqueous solution incipient impregnation porous carrier by mass ratio, stir and ageing 3~10h after, dry down at 100~120 ℃, calcine 0.5~10h down at 550~850 ℃ then, solid matter after the calcining becomes the powder of grain diameter below 100 orders through grinding, promptly gets target product.
Application process of the present invention is as follows:
Getting the 1000kg vegetable oil mixes with a certain amount of methyl alcohol, add strong agitation behind an amount of catalyst of the present invention, catalyst amount is 0.5~6.0% of a plant oil mass, the mol ratio of vegetable oil and methyl alcohol is 1: 3~1: 25, reaction time is 0.2~10h, reaction temperature is 30~85 ℃, after reaction is finished, centrifugation goes out solid catalyst, steam the reaction liquid phase methyl alcohol after standing demix, lower floor is glycerine and unreacted vegetable oil, the upper strata is a fatty acid methyl ester, be biodiesel, adopt the content of fatty acid methyl ester in the gas chromatography determination biodiesel, judge the conversion ratio of triglycerides.In order to prevent that free fatty from causing catalyst poisoning, the acid number of selected raw oil material need be lower than 1.0mgKOH/g oil, as using the higher raw material of acid number, needs to handle and can use through depickling.
The present invention has good catalytic activity to the ester exchange reaction of vegetable fat, and the ester interchange conversion rate of triglycerides is not less than 95% in the vegetable oil.Catalyst carrier is selected cheap porous carrier, can obviously reduce the catalyst cost.It is reusable that decaying catalyst is handled the back through regeneration, prolonged catalyst service life, further reduces the catalyst cost.
The specific embodiment
Embodiment 1
1, Preparation of Catalyst
At first measuring 1.0g sepiolite saturated water adsorptive value is 0.5g, get the 20g powdered sodium carbonate then, be dissolved in the 50g deionized water, then aqueous sodium carbonate is added 100.0g sepiolite powder, stir and ageing 3h, after 100 ℃ of following dryings, calcine 0.5h down at 550 ℃, it is powder below 100 orders that the gained solid matter obtains particle size through grinding, i.e. load type solid body base catalyst.
2, ester exchange reaction active testing experiment
Getting the 1000g vegetable oil mixes with 560g methyl alcohol, strong agitation behind the above-mentioned catalyst of adding 5g, reaction time is 0.2h, reaction temperature is 30 ℃, and after reaction was finished, centrifugation went out catalyst, steam the reaction liquid phase methyl alcohol after standing demix, lower floor is glycerine and unreacted vegetable oil, and the upper strata is a fatty acid methyl ester, is biodiesel.Adopt the content of fatty acid methyl ester in the gas chromatography determination biodiesel, the conversion ratio that obtains triglycerides is 95%.
Embodiment 2
1, Preparation of Catalyst
At first measuring 1.0g kaolin saturated water adsorptive value is 0.6g, get 650kg potassium nitrate powder then, be dissolved in the 600kg deionized water, the potassium nitrate aqueous solution is joined in the 1000kg kaolin powder then, stir and ageing 10h, after 120 ℃ of following dryings, calcine 10h down at 850 ℃, it is powder below 100 orders that the gained solid matter obtains particle size through grinding, i.e. load type solid body base catalyst.
2, ester exchange reaction active testing experiment
Getting the 100g vegetable oil mixes with 11g methyl alcohol, strong agitation behind the above-mentioned potassium nitrate of adding 6.0g/kaolin solid base catalyst, reaction time is 10h, reaction temperature is 85 ℃, and after reaction was finished, centrifugation went out catalyst, steam the reaction liquid phase methyl alcohol after standing demix, lower floor is glycerine and unreacted vegetable oil, and the upper strata is a fatty acid methyl ester, is biodiesel.Adopt the content of fatty acid methyl ester in the gas chromatography determination biodiesel, the conversion ratio that obtains triglycerides is 97%.
Embodiment 3
1, Preparation of Catalyst
At first measuring 1.0g 4A zeolite saturated water adsorptive value is 0.67g, get 50kg calcium nitrate powder then, be dissolved in the 100kg deionized water, then calcium nitrate aqueous solution is joined in the 150kg 4A zeolite powder, stir and ageing 5h, after 110 ℃ of following dryings, calcine 5h down at 700 ℃, it is powder below 100 orders that the gained solid matter obtains particle size through grinding, i.e. load type solid body base catalyst.
2, ester exchange reaction active testing experiment
Getting the 1000kg vegetable oil mixes with 942kg methyl alcohol, strong agitation after the above-mentioned calcium nitrate of adding 39kg/4A zeolitic solid base catalyst, reaction time is 6h, reaction temperature is 55 ℃, and after reaction was finished, centrifugation went out catalyst, steam the reaction liquid phase methyl alcohol after standing demix, lower floor is glycerine and unreacted vegetable oil, and the upper strata is a fatty acid methyl ester, is biodiesel.Adopt the content of fatty acid methyl ester in the gas chromatography determination biodiesel, the conversion ratio that obtains triglycerides is 99%.