Method for preparing biodiesel by using palm oil

Abstract

The invention provides a method for preparing biodiesel by using palm oil, which comprises: (1) pretreatment; (2) pre-esterification; (3) ester exchange reaction; and (4) coarse diesel decolorization. In the pre-esterification, standard raw material oil, methanol and sulfuric acid serving as a catalyst to form a mixed material, then sulfonated polyacrylamide in an amount which is 0.1 to 0.3 percent based on the mass of the standard raw material oil is added for continuous reaction to reduce an acid value, the reaction is finished after lasting for 1 to 2 hours, the reaction mixture is settled and demixed into a solid phase, a water phase and grease, the grease is subjected to ester exchange reaction to form coarse diesel, and finished biodiesel is obtained by decolorization. In the invention, a non-uniform phase reaction mode with a solid alkali as a catalyst is adopted, the catalytic activity of the catalyst is high, side reactions are fewer, separation is easy, corrosion to equipment is reduced, repeated use can be realized, and the amount of produced pollutants is reduced greatly; and an acid resistant water absorber can remove water generated in reaction in time in the pre-esterification process to make the reaction to perform toward a positive direction constantly, the reaction time is reduced effectively, energy consumption is lowered and the consumption of methanol is reduced.

Description

technical field [0001] The invention belongs to the field of biodiesel preparation, in particular to a method for producing biodiesel from palm oil. Background technique [0002] Biodiesel has excellent combustion performance, its viscosity and combustion heat index can reach the standard of ordinary diesel oil, and as a clean renewable green energy, it has excellent environmental protection, good safety (flash point high) and reproducibility are getting more and more attention. [0003] 75% of the cost of biodiesel is determined by raw materials, so whether biodiesel is economically feasible or not mainly depends on the choice of raw materials, not only requires sufficient sources of raw materials, but also requires low prices to have economic competitiveness. my country has a vast territory and rich varieties of oil resources, and palm oil is one of the oil crops with the highest yield per unit area. Due to the development of instant noodles and other fried foods, its pla...

AI Technical Summary

Problems solved by technology

However, because the esterification reaction is a reversible reaction, the low-carbon alcohol consumed in the reaction and the moisture generated by the reaction are not conducive to the positive movement of the reaction to produce biodiesel. Therefore, it is necessary to increase the amount of low-carbon alcohol to promote the forward reaction. Reaction cost, extended reaction time and increased energy consumption

Moreover, in the process of using liquid alkaline catalyst to produce biodiesel, the liquid alkaline catalyst is sensitive to moisture, and the activity will decrease when it meets water, and it is easy to cause side reactions