Investigation of Coal-Gasification Catalysis Reaction Mechanisms. Final Technical Progress Report, October 1980-August 1982

摘要

Coal char samples, prepared from Illinois No. 6 coal, with and without catalysts consisting of alkali metal carbonates, sulfates, chlorides, and hydroxides and calcium oxide, were gasified with H sub 2 O, D sub 2 O, H sub 2 , D sub 2 , CO sub 2 , and mixtures of gases at temperatures of 650 to 850 exp 0 C and at pressures of 0.1 to 3.5 MPa. The gasification rates were measured by a thermogravimetric balance system. Physical measurements including optical microscopy, x-ray fluorescence spectroscopy, scanning electron microscopy, exp 13 C nuclear magnetic resonance, electron paramagnetic resonance, Fourier transform infrared spectroscopy and surface area determinations (N sub 2 -BET) were conducted on the char residues following varying degrees of gasification. This report presents gasification rate data for chars cantaining a number of catalytic salts. In all instances, the catalytic effects of alkali metal carbonates followed the sequence, Cs exp + > K exp + > Na exp + >Li exp + where these were compared at the same atomic metal-to-carbon ratio. Limited tests with CaO-catalyzed char indicated it to be somewhat comparable to K sub 2 CO sub 3 in the case of steam gasification but less effective with other gaseous reactants, notably H sub 2 . Substitution of D sub 2 O for H sub 2 O yielded equivalent rates with K sub 2 CO sub 3 -catalyzed char but lower rates were observed for D sub 2 O with noncatalyzed char. The substitution of D sub 2 for H sub 2 yielded a higher gasification rate with K sub 2 CO sub 3 -catalyzed char but comparable rates were found for noncatalyzed char. 133 figures, 38 tables. (ERA citation 08:039923)