Synthesis of polycarboxylic acids from Kara-Keche coal

Abstract

This article presents the results of research on the oxidative destruction of coal in order to obtain polycarboxylic acids from them. Oxidation of carbons is an effective method for obtaining various chemical products and carbon materials based on them. In the destructive oxidation of coals, their organic mass is converted into a mixture of polycarboxylic acids (PCA) with a high yield of aromatic acids. The study of the composition and structure of these acids makes it possible to judge the peculiarities of the chemical structure of the solid fuel under study.

The mechanism of oxidation of separately original weathered coal, humic acids extracted from it and so-called residual carbon remaining after extraction of humic acids was studied. The products obtained from the oxidation of humic acids, original and residual carbon differ from each other. Humic acids and residual carbons are characterized by increased yields of carbon dioxide and volatile acids with steam. The yield of water-soluble PCA is reduced in the following sequence: original carbon ˃ humic acids ˃ residual carbon, and yield of insoluble acids in reverse order. According to the results of the study, it was revealed that in the composition of water-soluble PCA obtained from weathered brown coals, in addition to true carboxylic acids, there are other more oxygen-rich compounds, the presence of keto and hydroxy acids is possible.