Conversion of brown coal in supercritical water without and with addition of oxygen at continuous supply of coal–water slurry

Abstract

A study of conversion of organic matter of brown coal in supercritical water (SCW) at 30 MPa, 400−760 °C and continuous supply of coal–water slurry (CWS) into a tubular reactor is presented. It was found that 48−63% (depending on the SCW temperature) of coal organic matter (COM) is ejected from CWS coal particles as liquid and gaseous products when they move through the reactor. We termed this stage of SCW conversion as dynamic conversion (DC) of coal. It turns out that the particles which underwent the DC stage did not aggregate in the reactor during static conversion (SC) within a coal layer due to continuous pumping through this layer. The experimental data on the composition of DC and SC products, degree of coal conversion, and the data on the degree of combustion of carbon in the presence of oxygen are given.