A Experimental Study Of Biodiesel Production Using Supercritical Methanol Reaction Coupling Separation Reactor

The rapid increase of world energy consumption and the serious environment problems make people gradually realize that fossil energy already can't sustain human sustainable development. All countries speed the pace to develop alternative energy. Biodiesel receives extensive attention and much study because of its good combustible performance, environmental performance and reproducibility. Currently biodiesel industry is still in the initial stage and the main limiting factor is the high cost. According to statistics,75%-80% biodiesel cost is raw material. Using cheap raw materials is an effective way to reduce cost to improve biodiesel market competitive powerCurrently biodiesel production mainly uses the alkali catalytic process. In this process, the system of alcohols and grease is incompatible, mass transfer effect is poor, the demand for raw materials is high, the purification of products is difficult and a great deal of waste liquid polluting environment is produced. Supercritical methanol system preparation for biodiesel is a kind of green environmental production process, In recent years the research becomes focus. Supercritical methanol and grease is a very good compatible system,which strengthens mass transfer and the ester exchange, so the reaction rate is greatly improved; Supercritical methanol system for biodiesel production can achieve high yield whithout any catalyst, the subsequent separation for product process is simplified. Free fatty acids and moisture content of materials have no impact on supercritical ester exchange reaction, so the process can effectively use cheap raw materials, such as acidification oil, edible oils, to reduce biodiesel raw material costs.This paper designs a set of biodiesel production device. As a whole,the reactor is a tower. The mode of operation is half successive. Raw material oil is feeded one-time, and methanol is feeded continuously from the bottom. The reactor couples reaction process and the separation process. Water formed in reaction process can be timely separated which can improve the reaction rate and biodiesel production rate. Diversion tube is set up inside the reactor. Rising supercritical methanol stir oil,which makes methanol and oil mix better. and react more fully. Supercritical methanol system within reactor updated constantly by continuously methanol feeding. The mol ratio of methanol to oil can achieve a higher value under lower total, which can meet the requirements of supercritical ester exchange. So the energy consumption and the cost of biodiesel can be reduced.This paper uses acidification oil as raw material, using supercritical methanol process to produce biodiesel. Experiment studies the law of ester exchange reaction in supercritical methanol, The influence of pressure, temperature, methanol ventilation and the response time to the reaction rate and the ester exchange reaction equilibrium conversion was investigated.The orthogonal experiment optimize process conditions. Experimental results show that in the test range each factor to the ester exchange reaction influence size is as follows:the reaction time>reaction temperature> methanol ventilation>reaction pressure, The optimizational best technological conditions for:the reaction:reaction temperature 280℃, reaction pressure 9MPa, methanol ventilation 6L/h, reaction time 90min,and under the conditions fatty acid methyl yield can reach 85%. This paper establishe kinetics model in supercritical methanol exchange reaction to provide theoretical basis for industrial production...