Extraction Of Humic Acid from Local Brown Coal and Synthesis of Its Vinyl Ether

Abstract

This article presents research on the extraction of humic acid from brown coal samples obtained from the Angren and Apartak coal deposits of Uzbekistan and the Karakyche deposit of Kyrgyzstan, as well as the heterogeneous-catalytic synthesis of its vinyl ether. The coal samples were pre-oxidized with nitric acid, followed by alkaline extraction to isolate the humic acid. The effect of oxidation conditions (acid concentration, mass ratio, and time) on the humic acid yield was investigated. The vinyl etherification of humic acid was carried out in the gas phase with acetylene in the presence of a Zn(CH₃COO)₂/Al₂O₃ catalyst. The functional composition of the obtained products was confirmed by IR spectroscopy.