1.Preparation of biodiesel by enzyme-catalyzed transesterification
Enzyme-catalyzed transesterification is the process of using lipase to catalyze the production of biodiesel under certain conditions. That is to say, under the action of enzymes, substances such as low-level alcohols (methanol or ethanol) are used to replace glycerol in fatty acid glycerides in the oil, so as to produce fatty acid alkyl esters, thereby reducing the length of carbon chain, increasing fluidity and reducing viscosity, and meeting the fuel energy standards.
The preparation of biodiesel by this method has the advantages of a simple extraction, mild reaction conditions, a small amount of alcohol, easy recovery of glycerol and no waste generation, etc. Besides, this process can further synthesize other high-value products including biodegradable lubricants and additives for fuels and lubricants. Although enzyme-catalyzed transesterification has many obvious advantages, biodiesel is not widely used in large-scale production. As it still has some problems to overcome.
The immobilization technology with simple preparation and low cost are sought. Moreover, it can produce an immobilized enzyme with high catalytic activity after repeated recycling. It has become a new research direction to realize the requirement of automatic separation and automatic production.
2. Immobilized carrier material
With the continuous development of technology, continuous research, and development of new materials. Various new materials are used as carriers for immobilized enzymes. The immobilized enzyme technology has been developing continuously. It greatly promotes the process of replacing fossil energy with biodiesel.
2.1 Immobilized carrier material
With the continuous development of technology, continuous research, and development of new materials. Various new materials are used as carriers for immobilized enzymes. The immobilized enzyme technology has been developing continuously. It greatly promotes the process of replacing fossil energy with biodiesel.
2.2 Magnetic Materials
In 1973, Robinson et al. first used magnetic materials as carriers for enzyme immobilization. It not only has some excellent properties of nanomaterials but also facilitates separation. The electromagnet can be used in industrial production to separate the immobilized enzyme from the product, and thus achieve the goal of process automation.
2.3 high-molecular compound
Natural polymer materials have the advantages of low cost, wide source, and good biocompatibility. When such materials, such as chitosan, chitin and sodium alginate, are added with calcium chloride, they have strong mechanical properties. In the preparation process of biodiesel which needs stirring, the structure is stable.