Technique for hypercritical continuous preparation of biological diesel oil and equipment thereof

Abstract

The invention relates to preparation technology for bio-diesel and the producing equipments. The technology for supercritical continuously producing of bio-diesel comprises the following steps: preparing a reserve of methanol and vegetable oil in a mole ratio of 30-50 to one; mixing methanol with vegetable oil in a mixer after preheating the methanol and vegetable oil at a constant temperature respectively of 200DEG C and 250 DEG C which are pumped by high pressure pump into two independent preheaters; sending the fully-mixed methanol and vegetable oil into the tubular reactor at a temperature of 300-350 DEG C, a pressure of 18-20MPa and letting the reaction last for eight to ten minutes; 4.putting the reaction products into a preliminary separator after a complete reaction, wherein the methanol is separated for recycling use and the head product is decompressed and cooled; taking the cooled substance out and keeping the cooled substance still for separation; distilling the upper and lower layers respectively, wherein the bio-diesel is obtained by steaming the methanol out of the upper layer and the by-product of glycerol is obtained by steaming out methanol out of the lower layer; putting the steamed methanol into a tank for recycling use. The invention is characterized by simple technology, environment protection, rapid preparation and high yield.

Description

technical field [0001] The invention is not only the utilization of biomass energy in the field of energy, but also a technology for efficiently coupling mass transfer, reaction and separation in the field of reaction engineering, and specifically relates to a process for preparing biodiesel and its equipment. Background technique [0002] Biodiesel is a renewable energy produced with vegetable oil or animal oil as raw material. It is a high-quality petroleum diesel substitute with three advantages: renewable, clean and safe. It is of great strategic significance. In recent years, many countries in the world have vigorously developed this biodiesel technology and promoted its industrialization process, especially the development and commercialization of biodiesel technology in developed countries have achieved great progress. In my country, the industrialization of biodiesel started late, but developed rapidly. The Chinese Academy of Engineering has proposed the developmen...

AI Technical Summary

Problems solved by technology

However, chemical synthesis of biodiesel has the following disadvantages: complex process, difficult product separation, long reaction time, high raw material requirements, waste acid and waste alkali discharge, etc.

However, there are the following disadvantages in the synthesis of biodiesel by enzymatic method: low conversion rate; due to the specific catalytic function of the enzyme, the adaptability of the enzyme to natural oils with complex components is poor; short-chain alcohols have certain toxicity to the enzyme, and the enzyme is easily lost activity, the catalyst life of the enzyme is short, the price of the enzyme catalyst is expensive, the preparation cost is high, and the production cycle is long

[0005] The preparation of biodiesel by solid catalyst heterogeneous catalysis is also a research hotspot at present. The solid catalysis method can solve the separation problem of the product and the catalyst very well, and it avoids the intermediate process required by the process of using a homogeneous catalyst such as sodium hydroxide or sodium methoxide. And, washing steps, and will not produce waste acid and waste lye, but the solid heterogeneous catalyst method fails to solve the mixing problem of reactants, so that the heterogeneous reaction rate is relatively slow, and the oil conversion rate is relatively low

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