Hydrogasifier development for the Hydrane process. Monthly progress report, February 1978

Abstract

Testing of the /sup 1///sub 4/ TPH hydrogasifier reactor was continued with emphasis on longer duration (1 to 8 hr) runs with bituminous coals reacted under conditions yielding no liquid hydrocarbon products and with H/sub 2//CH/sub 4/ feed gas mixtures to simulate partial recycle of product gases. Several tests were made with Illinois No. 6 bituminous coal. Cities Service made two studies utilizing the computer model of the hydrogasification process: (1) Effect of burning coal in the combustor, instead of hydrogen, for satisfying the coal preheat requirements; and (2) Effect of carbon conversion level in the hydrogasifier on the economics for processing Montana Rosebud subbituminous coal. Varying the carbon conversion in the hydrogasifier with Rosebud coal from 37.2% to 99.9% resulted in decreased capital equipment costs and decreased SNG costs. Unlike the case for bituminous coal, the overall thermal efficiency for the Rosebud subbituminous coal decreased only slightly. There is no significant economic advantage of burning coal in the combustor instead of hydrogen to satisfy the coal preheat requirements. Burning coal complicates the design of the reactor system requiring three sets of injector assemblies. In the reactor model analyses, an inability to correlate model predictions to measured /sup 1///sub 4/more » TPH carbon conversion results for both bituminous and subbituminous coals led to a reconsideration of some basic assumptions used in Anthony's coal particle devolatilization model. As a result, some improvements were made and the effort to correlate the model to the experimental results is continuing. Multiple regression analysis was used to study the effect of injector mixing on overall carbon conversion achieved in the /sup 1///sub 4/ TPH hydrogasification tests. Preliminary results indicate that operation at less than optimum injector mixing adversely affects the hydroconversion of bituminous coals, but that there is little, if any, effect on conversion of subbituminous coal.« less