Flash hydrogenation of subbituminous

Figure 1. Flash hydrogenation of subbituminous coal pressure = 500 psi Ht flow rate 1 Ib/h coal feed rate 1 Ib/h.

The Kinetics of Flash Hydrogenation of Lignite and Subbituminous Coal... 

Flash hydrogenation is a short residence time (1 to 10 sec) gas-phase, non-catalytic process in which pulverized coal is rapidly heated (20,000-30,000° C/sec) in hydrogen to obtain liquid and gaseous hydrocarbons directly. Experiments were conducted in a 2 lb/hr, 1 ID x 8 ft long downflow tubular reactor in the range of 500° to 900°C and 500 to 3000 psi H2 pressure for North Dakota Lignite and New Mexico subbituminous coal (L). The ultimate analyses of these coals are given in... 

The formation of gas was low. From the carbon balance, only 3% of the total carbon formed gaseous products. The hydrogen consumption was approximately 3100 scf/bbl, of which nearly 80% was consumed in liquid hydrogenation. This preliminary result demonstrated that the flash pyrolysis coal tar derived from a subbituminous coal is amenable to hydrorefining. 

The results of this study showed that flash pyrolysis subbituminous coal tar can be hydrorefined. Ni-Mo supported on alumina was the most effective catalyst for hydrorefining flash pyrolysis subbituminous coal tar among the five types of catalysts tested. The removal of asphaltenes and preasphaltenes was easy to achieve. Catalyst selection should emphasize heteroatoms removal efficiency and hydrogen consumption. The catalyst life is an equally important selection criterion although this program has not completed catalyst-life studies. It will be determined in the future. 

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