Fuel, Vol.78, No.6, 713-719, 1999
Effects of mineral matter on products and sulfur distributions in hydropyrolysis
The effects of the mineral matter on the product yield and sulfur distribution in hydropyrolysis and pyrolysis of Chinese Hongmiao lignite were investigated using a fixed-bed reactor. The volatile sulfur-containing gases (H2S,COS,CH3SH) were also analyzed as a function of pyrolysis temperature. Coal samples were treated with HCl/HF or HCl/HF and CrCl2 solution to eliminate minerals and pyrite respectively. In hydropyrolysis, demineralized Hongmiao lignite showed lower yields of tar and water than the raw coal. Demineralization cannot only minimize the fixation effect of basic mineral matter on sulfur-containing gases, but also increase the sulfur distribution of the tar. Further, from the evolution profiles of sulfur-containing gases, it is possible to elucidate the contribution of minerals, pyrite and organic sulfur to the sulfur evolution. Pyrite may not be the only source of COS formation.
Keywords:BROWN COALS;RAPID PYROLYSIS;FLASH PYROLYSIS;BITUMINOUS COAL;ACIDIC GROUPS;HYDROGENATION;DECOMPOSITION;GASIFICATION;CATIONS;CALCIUM