Method of preparing biological diesel oil from high acid value abandoned grease by titanium tetrachloride catalysts

Abstract

The invention discloses a preparing method of diesel through catalyzing high acid value waste grease with titanic chloride, which comprises the following steps: (1) adding active carbon with mass percent at 0.5%- 1.5% into waste grease; getting pre-processing waste grease; (2) adding the waste grease, carbinol and titanic chloride into reactor; mixing evenly; heating at normal pressure; keeping at 65-70 deg.c; stirring; refluxing and reacting at 3-8 h; getting reacting matter; stewing; dividing to upper and low layer; setting the upper layer as higher fatty acid methyl ester liquid of light methanol and titanic chloride; (3) distilling the upper liquid under normal pressure at 65-70 deg.c; stripping retained carbinol; setting remainder as aliphatic acid methyl ester with titanic chloride (TiCl4); washing to neutral; removing impurity; drying; getting biological diesel. This invention possesses merits of simple craft, small pollution; high production rate and good quality.

Description

technical field [0001] The invention relates to a method for producing biodiesel by using waste oil, and belongs to the technical field of oil chemistry. Background technique [0002] At present, the continuous reduction of oil reserves, the continuous growth of energy demand, the deteriorating environmental pollution caused by the combustion of fossil fuels and the intensification of the greenhouse effect make the development of new, environmentally friendly, non-petroleum renewable energy a future The inevitable trend of energy development. [0003] Recently, biodiesel, a renewable and clean energy source, has received widespread attention. Biodiesel refers to high-grade fatty acid methyl or ethyl esters made from oil crops, wild oil plants, engineering microalgae and other aquatic vegetable oils, animal fats, and catering waste oils through transesterification process, which can replace diesel as fuel . Biodiesel emerges at the historic moment because of its low releas...

AI Technical Summary

Problems solved by technology

But use sulfuric acid as catalyst, its catalytic efficiency is low (many side reactions, reaction time is generally more than 10 hours), catalyst consumption is bigger and the color of the product obtained is dark, needs to use the reaction equipment of acid corrosion resistance simultaneously, has improved production cost

The traditional base-catalyzed method (using NaOH, or CH 3 Na, etc.) have the advantages of high efficiency and low requirements for equipment, but this process has high requirements for raw materials, and waste oil with high free fatty acid and water content cannot directly use this process

The acid-base two-step method can solve this problem, but the process is too complicated, which will inevitably greatly increase the production cost of biodiesel

Chinese patent CN1743417 discloses a two-step process using solid iron sulfate and potassium hydroxide as a catalyst to produce biodiesel, with a total yield of 93.0%, but iron sulfate is almost insoluble in oil and alcohol. If you want to increase the contact area of ​​the catalyst, It is necessary to use finer powder, which brings trouble to the separation of the catalyst, and it is difficult to completely remove the catalyst by centrifugation. When potassium hydroxide is added in the second step to catalyze the reaction, iron hydroxide will precipitate, which reduces the catalytic efficiency. It also increases the difficulty of post-processing

Chinese patent CN1760335 discloses a method for preparing biodiesel by simultaneous esterification and transesterification of high-acid oil, but the temperature required for the reaction generally reaches 180°C, and the pressure generally reaches 6MPa. The conditions are relatively harsh, and the amount of methanol used is relatively high. Large, its catalyst zinc acetate, lead acetate, cadmium acetate is more expensive, and not friendly to the environment

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