IIR Spectra of Low-Metamorphosed Barzas Coal Subjected to Thermal Treatment in Carbon Dioxide Medium

Abstract

Using FTIR spectroscopy, elemental analysis and gas chromatography methods, the temperature effects on the thermal transformations of low-metamorphosed Barzas coal (sapromixite) in carbon dioxide media have been studied. According to the IR spectroscopic data, an increase in the relative content of alkyl groups (-CH3 and >CH2) in the solid residue of sapromixite with a rise in the process temperature up to ~ 475°C was observed, followed by a rapid decrease in their concentration at higher heat treatment temperatures. Such behavior may be associated with an initial accumulation of alkyl fragments, formedfrom the coal matter, and their subsequent transition into the gaseous phase. A close relationship (an antibate dependence) has been discovered between H/C atomic ratios in resin-containing solid products of thermally treated Barzas coal and the yields of gases formed during its pyrolysis. Chromatographic analysis of liquid products formed after Barzas coal heat treatment at 475°C showed that the main organic constituents of liquid phase (about 3-5% by weight) were phenol and its methyl-and dimethyl derivatives (their total content in methylene chloride extract was of > 77% by weight).