Reaction of Fatty Acid Methyl Ester with Monoethanolamine and Diethanolamine

The course of the reaction between lauric acid and monoethanolamine as well as the reaction of methyl laurate with monoethanolamine and diethanolamine were investigated. Thin layer chromatography with flame ionisation detector was used for reaction mixture analysis. The fatty acid methyl ester is more suitable for production of monoethanolamide and diethanolamide. Sodium methoxide or potassium hydroxide (0.02 mol % ester) was used as suitable alkaline catalysts of reaction. The optimal temperature of methyl laurate or coconut oil with diethanolamine reaction is 80°C. Higher temperatures (over 100°C) lead to a higher concentration of amide ester in the product.

Construction of Molecular Model and Adsorption of Collectors on Bulianta Coal

To study the effects of different oxygen functional groups on the quality of flotation clean low-rank coal, two kinds of collectors with different oxygen-containing functional groups, methyl laurate, and dodecanol, were selected and their flotation behaviors were investigated. The Bulianta coal was the typical sub-bituminous coal in China, and the coal molecular model of which was constructed based on proximate analysis, ultimate analysis, 13C-NMR, and XPS. The chemical structure model of the coal molecule was optimized, and the periodic boundary condition was added via the method of molecular dynamics methods. The different combined systems formed by collectors, water, and a model surface of Bulianta coal have been studied using molecular dynamics simulation. The simulation results of dodecanol and methyl laurate on the surface of Bulianta coal show that dodecanol molecules are not evenly adsorbed on the surface of coal, and have higher adsorption capacity near carboxyl and hydroxyl groups, but less adsorption capacity near carbonyl and ether bonds. Methyl laurate can completely cover the oxygen-containing functional groups on the coal surface. Compared with dodecanol, methyl laurate can effectively improve the hydrophobicity of the Bulianta coal surface, which is consistent with the results of the XPS test and the flotation test.