Pyrolysis under H 2 and He of Utrillas coal

Abstract

Pyrolysis and hydropyrolysis at low temperature, 600 °C, of Utrillas coal were compared to determine differences in the product composition. Pyrolysis was carried out under helium at atmospheric pressure in a horizontal fixed-bed reactor with a heating rate of 7 °C min −1, and hydropyrolysis under hydrogen (3 MPa) in a fixed-bed gas-swept reactor with a heating rate of 10 °C min −1. Gas and water yields were similar, but the gases from hydropyrolysis had higher methane and lower CO 2 contents and therefore higher heating power. Tars from both techniques had similar elemental analyses but structural differences were observed by FT-i.r., 1H n.m.r. and gas chromatography. Hydropyrolysis yielded more tars than pyrolysis. The chars had analogous elemental and proximate analyses and calorific values. Hydropyrolysis was more effective for desulphurization than conventional pyrolysis.