Abstract:

The undergraduate talent training plan for applied chemistry and other majors includes the use of the principles and methods of chemistry needed to realize recycling. However, there are few comprehensive experiments on recycling in the training plan. In this experiment, waste rapeseed oil and methanol are used as starting materials and sodium hydroxide and choline chloride as catalysts. The generated byproduct glycerin combines with choline chloride to form an eutectic system in situ, which is immiscible with the product/substrate phase, facilitating the fast removal of glycerin from the reaction system, and thus, promoting the reaction forward, simplifying the post-treatment process and improving the purity of the product. Moreover, the separated eutectic system can be used directly for another run. In addition, the calorific value of biodiesel is comparable to that of petrodiesel according to the results of measurements of the heat of combustion. Generally, the chemical reagents used are low-toxic and the experiment is composed of a series of fundamental operations in organic, physical and analytical chemistry experiments, and is therefore a promising experiment candidate for a comprehensive chemistry laboratory for undergraduates. This experiment also helps students to systematically understand and master the technology used and to train their initiative and exploration spirit and comprehensive practical ability. Besides, it is beneficial to integrate the ideology of environmental protection, low carbon usage and recycling into comprehensive chemistry experiment teaching.

Key words: Waste rapeseed oil, Resource, Transesterification, Biodiesel, Comprehensive chemistry experiment