Process for producing biodiesel from high acid number grease

Abstract

The invention relates to a method for making biological diesel oil, in particular to a method for making biological diesel oil by grease with high acid value, belonging to the renewable energy resource technical field. The production formula of the method in weight portion is as follows: 100 portions of grease, 20 portions of bridle chain alcohol, 1 to 10 portions of fatty acid methyl ester, 0.5 to 4 portions of catalyst and 0.1 to 5 portions of alkalescent buffer substances. The concrete steps are as follows: the grease is put in a reaction kettle provided with a high speed blending device, added with the bridle chain alcohol and the fatty acid methyl ester, and undergoes high speed stirring at the room temperature for 1 to 4 hours so as to form emulsion, and the emulsion is added with the alkalescent substances and undergoes high speed stirring for 1 t0 4 hours; KOH or NaOH is dissolved in methyl alcohols to prepare the KOH or NaOH methanol solution with mass percentage concentration between 8 and 10 percent, which is used as catalyst; the emulsion is added with the catalyst and undergoes back flow reaction for 0.5 to 4 hours; after the reaction, reactants are cooled down to the temperature of 40 DEG C and then undergo standing separation to remove side products such as glycerin, etc. on the lower layer, and coarse products of the biological diesel oil are obtained; the coarse products of the biological diesel oil undergo normal pressure distillation to recover excessive bridle chain alcohols and undergo molecular distillation to obtain the qualified biological diesel oil. The method of the invention has the advantages of simple production process, mild condition, easy post treatment, low manufacturing cost, good economical efficiency of process and easy realization of industrialization, and has a good prospect for large-scale popularization and application.

Description

technical field [0001] The invention relates to a method for producing biodiesel, in particular to a method for producing biodiesel from oil with high acid value, and belongs to the technical field of renewable energy. Background technique [0002] Liquid fuel is one of the cornerstones of maintaining the normal operation of modern society and is the most important power fuel. With the development of the world economy, global fossil resources are becoming increasingly depleted, and the supply situation of liquid fuel is becoming increasingly severe. Energy shortage has become one of the important factors restricting the economic development of all countries in the world. my country imported 120 million tons of crude oil in 2004, accounting for 44% of the total processed crude oil. Excessively high import dependence has threatened the national energy strategy security. In terms of energy consumption structure, my country is a big diesel consumer. In 2003, it consumed 83.07 m...

AI Technical Summary

Problems solved by technology

When the acid value of the used oil > 0.5, the industry usually uses the "two-step" production process of first carrying out the oil acid catalyzed esterification reaction and then carrying out the alkali catalyzed transesterification reaction (that is, first carry out the oil acid catalyzed esterification, and then carry out the oil acid catalyzed esterification by The esterification reaction removes the acid value, and then carries out the intermediate step of washing to reduce the acid value to below 0.5, and then uses sodium methoxide as a catalyst to carry out the transesterification reaction) to avoid oil saponification. This method has complicated procedures, large equipment investment, and sewage discharge Large quantity, high cost of environmental protection treatment