Study On Preparation Of Biodiesel Catalyzed By Solid Base

Recently, the situation of the fossil energy will bring a great effects on our country's development due to the tension of the oil supply and the rising price of the international crude oil. And more, the strengthening of green house effect and the improvement of people's consciousness of environment protection, which cause hunting for kinds of renewable energy becomes the focus of people's attention. Durying these kinds of energy, the research on alternative liquid fuel, especially the biodiesel has been carried out extensively.The main component of biodiesel is a mixture of several kinds of fatty acid methyl ester. Biodiesel is producted by animal fat or vegetable oil with a short chain alcohol. Biodiesel is a renewable, non-toxic, and biodegradable green environmental friendly diesel fuel. Besides, it is possessed of another inherent excellent properties, such as excellent combustion and lubricity, low viscous and high catane. Many studies have shown that molecular weight of biodiesel is very close to crude oil and the combustion characteries of biodiesel is similar to the diesel fuel. Therefore, biodiesel can be directly used in diesel engines, which need some slight modification or not.Solid base refers to this kind of solid that can accept proton or give electron. The transesterification reaction catalyzed by solid-base can avoid some problem in tradational homogeneous acid or base catalyzing that the seperation of products and the used catalyst is difficult and the waste water in washing products pollute environment. Therefore, the preparation of biodiesel catalyzed by solid catalyst via transesterifaction is the hot point in the methods of biodiesel production. In addition, solid-base is highly-actived, highly-selective, mild, reused and so on. It is meaningful for the rising biodiesel industry in our country.Biodiesel production catalyzed by solid-base is main method during all the preparation methods. However, a highly-actived and cheap catalyst is more important. The study of this paper is to preparate a highly-actived, chaeap and easily available catalyst CaO. And it was applicated in the transesterification reaction. The reusable times of CaO was experimented. Finally , the reason of catalyst losing activity and getting toxic were analyzed. The synthesis, characterization and application of CaO were investigated in the paper. The main results are as follows:1. A simple, quick and low cost route was developed to preparate porous CaO microsphere. After the experiment of CaO preparation, we get the best optimum preparation conditions of CaO with a high surface area, large size, uniformity and porosity.2. Biodiesel production was preparaed by soybean oil and methonal catalyzed by porous CaO microsphere via transesterification. By single factor experiments and orthogonal tests, the optimal conditions were concluded.3. An accurate determination method of fatty acid methyl esters in biodiesel from soybean oil by gas chromatography was developed. The method is simple, accurate and has a high resolution and good reproducibility.4. Under the optimal conditions, the reusable time of CaO was experimented and the reasons of catalyst losing activity and getting toxic were analyzed.5. The characteristics of self-biodiesel were tested, and almost all the characteristics beside the catane are up to the ASTM standard.