A Experimental Study Of Biodiesel Production Uses Two-step Method In Airlift Loop Reactor

As fossil fuel reserves rapidly decline and the people around the world raise environmental awareness,every country in the world accelerates the pace of development of alternative diesel fuels.Biodiesel has been a hot point of research in recent years,because it is a renewable, environmental protection biomass fuel. The main problem of biodiesel is its high price at the present time, according to statistics, the 75-80 percent preparation of cost of biodiesel is raw material costs, so using cheap raw material is the key of industrial progress of biodiesel.This article bases on acidification oil as raw material and uses self-designed airlift reactor, aiming to get a low-cost production of biodiesel process and equipment for industrial production:This articl'conclusion can provide theoretical references for biodiesel industrial production.Using acidification oil, methanol as raw materials, p-toluene sulfonic acid catalyzes gas phase pre-esterification reaction. The single factor experiment and the orthogonal experiment combination design was adopted to study the effects of the volume flow of Methanol,catalyst dosage,reacting time,reaction temprerature on esterification conversion rate.The results indicated the order of factors that influence the esterification conversion rate within the experimental range was as follows reaction temprerature>the volume flow of Methanol>catalyst dosage>reaction time. The optimum technological conditions of the pre-esterification reactioin was found:reaction temperature is 115℃, reaction time is 2h, catalyst dosage is 2%and the volume flow of Methanol is 180ml/h. The acid value of acid oil can fall below 2.5mgKOH/g at the optimum condition, transeserification catalyzed by alkali next step never mind of saponification. The transesterification of the treated acidification oil and methanol was carried out by using NaOH as catalyst to produce biodiesel. Through orthogonal analysis, the optimum technological conditions obtained for the transesterification were set at reaction temperature 70℃, reaction time 2 h, and catalyst dosage 0.3%, the volume flow of Methanol is 90ml/h. The yield of transterification was 88.2%. The biodiesel quality complies with the GB/T20828-2007.On the basis of pocket lab of chapter three and in view of producing economy,we can determine the experimental operation parameters of airlift loop reactor and change the velocity of methanol flow to test the experimental efficiency. In the experiment the pre-esterification reaction,the optimum operation parameters of airlift loop reactor is reaction temperature is 115℃, reaction time is 2h, catalyst dosage is 1%and the volume flow of Methanol is 6.5L/h. In the experiment the transesterification reaction,the optimum operation parameters of airlift loop reactor is reaction temperature is 70℃, reaction time is lh, catalyst dosage is 0.3%and the volume flow of Methanol is 6.5L/h. The yield of transterification was 88.2%. The biodiesel quality complies with the GB/T20828-2007. Compared with mechanical agitation reactor, the airlift loop reactor can reduce the cost of biodiesel production.