Method for preparing biodiesel from hemp plant oil

Abstract

The invention relates to a method for preparing biodiesel from hemp plant oil; and a co-solvent is adopted to fully dissolve alcohol and oil to be homogeneous, is added with a solid catalyst, and is pumped into a tubular reactor to carry out continuous reaction. A static mixer is arranged in the reactor. The reaction temperature is 60 to 300DEG C, the reaction pressure is 1 to 30MPa, the molar ratio of methanol to oil is 3 to 100, the molar ratio of the co-solvent to oil is 1 to 30, the consumption of the catalyst is 0.5 to 5 percent of the mass of the oil, and the reaction time is 10 to 120min. After reaction, through cooling, the catalyst is filtered and recovered, and then enters a flash tank to recover the alcohol and the co-solvent, and crude biodiesel is prepared by staying still and being layered; and after distillation, a biodiesel product is prepared, and the quality yield is more than 95 percent. The process is simple, the reaction can be carried out continuously, the catalyst, the alcohol and the co-solvent can be recycled, the equipment investment is low, and the production cost is low.

Description

technical field [0001] The invention relates to a method for preparing biodiesel, in particular to a method for preparing biodiesel by using hemp vegetable oil as a raw material, and belongs to the technical field of biological and chemical engineering. Background technique [0002] Biodiesel is fatty acid methyl ester prepared by transesterification of animal and vegetable oils and methanol. Commonly used methods include acid catalysis, alkali catalysis, solid acid-base catalysis, enzyme catalysis, supercritical method, etc. Usually KOH is used as a catalyst, the molar ratio of methanol and oil is 6:1, and the reaction is carried out at 65°C for 1 hour. After the product is separated, the upper layer is distilled with methanol, pickled, washed with water, dried, and rectified to obtain fatty acids. methyl ester. Chinese patent CN 101138737A discloses a molecular sieve solid base catalyst and its application in the production of biodiesel. MCM-41 mesoporous molecular sieve ...

AI Technical Summary

Problems solved by technology

Chinese patent CN 101138737A discloses a molecular sieve solid base catalyst and its application in the production of biodiesel. MCM-41 mesoporous molecular sieve is used as a carrier to load alkali metal oxides to catalyze grease to prepare biodiesel, which can overcome the separation of homogeneous catalysts. difficult question

Chinese patent 200610114033.4 discloses a method and device for producing low-carbon olefins by catalytic cracking of oil or fatty acid. A fluidized bed reactor is used. The reaction temperature is 400-700°C. Water vapor needs to be added during the reaction process. The amount of catalyst used is 5% of the oil quality. ~25 times, the catalyst will be deactivated after one reaction, and the cracking products include C 1 、C 2 、C 3 、C 4 , CO, CO 2 etc., the composition is complex, the reaction conditions are harsh, and the production cost is high

[0003] The usual biodiesel production method is batchwise. If the acid value of the raw material is high, the oil needs to be pre-esterified, the process is complex, and the pollutants are discharged more. Both high-temperature cracking and hydrogenation processes have harsh reaction conditions and low product yields. shortcoming

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