Preparation method of biological diesel oil

Abstract

The present invention relates to biodiesel oil preparing process, and provides one biodiesel oil preparing process with solid acid and solid alkali as catalyst to lower the activating energy and raise the reaction speed. The biodiesel oil preparing process includes the following steps: reacting dried grease with high free fatty acid content, methanol or ethanol, and cosolvent in the molar ratio of 1 to 6-1 to 6.05 in the first fixed bed reactor with solid catalyst A at 60-65 deg.c for about 3 hr; separating the oil phase from others; reacting the oil phase in the second fixed bed reactor with solid catalyst B with methanol or ethanol and cosolvent at 60-65 deg.c for about 3 hr; distilling out methanol or ethanol and cosolvent; separating the biodiesel oil from glycerin phase; and distilling the biodiesel oil phase to obtain biodiesel oil product. The catalyst of the present invention has high catalytic activity and can lower the activating energy and raise the reaction speed.

Description

technical field [0001] The invention relates to a method for preparing biodiesel from oil high in free fatty acid by using solid acid and solid base as catalysts for heterogeneous catalytic reaction. Background technique [0002] Diesel is an important fuel oil and the main power fuel for many large machinery (such as trucks, ships, diesel locomotives and generators, etc.). It has the advantages of high power and low price, so it has been widely used. According to estimates, the current annual demand for diesel in my country has exceeded 80 million tons. [0003] Mineral diesel is mainly obtained through petroleum refining process. At present, domestic oil production capacity is far lower than the domestic demand for oil products, which requires a large amount of imports. Due to changes in the international situation, the stability of oil imports is also threatened by some potential factors. If the situation of oil imports changes greatly, it will seriously affect the sust...

AI Technical Summary

Problems solved by technology

[0009] At present, the production of biodiesel by transesterification mainly adopts chemical methods. The traditional chemical method transesterification uses homogeneous catalysts, such as NaOH, KOH, sodium methylate, etc., and the dosage is about 1%. The reaction temperature is generally the boiling point of methanol. The speed is fast and the conversion rate is high, but at the same time there are obvious disadvantages: the process is complicated, the alcohol must be excessive, and the subsequent process must have a corresponding alcohol recovery device; high energy consumption, dark color, because unsaturated fatty acids in fat are easy to deteriorate at high temperatures , the esterification product is difficult to recycle, and the cost is high; the product must be neutralized and washed to bring a large amount of industrial wastewater, causing environmental pollution; the generation process has waste lye discharge, which is not conducive to environmental protection requirements

However, most of the conventional super strong solid bases are complicated to prepare, expensive in cost, poor in strength, and easily destroyed by CO in the atmosphere. 2 、H 2 Contaminated by impurities such as O, and the specific surface area is small

Images