Distillable product yields, coal liquefaction

An enormous amount of work both at bench scale and at pilot plant scale have been conducted to study the production of liquid and gaseous hydrocarbons from coal. Since most of the analytical methods are either very time consuming or very specialized, almost all the data available on the coal liquefaction process are based on distillation data or on the assumption that all products which are not insoluble solids are converted. It is known that products of liquefaction vary based on coal, reaction conditions, and media of reaction hence, conversion and yield may be based on very different products. 

The SRC-II process is one of several coal liquefaction processes currently under development in programs funded by the Department of Energy (DOE). Product from this process is a distillate that is relatively attractive as a feed for conversion to transportation fuels. Essentially all of the nitrogen, sulfur, and oxygen can be removed in a single catalytic hydro-treating stage to yield a naphtha that is an excellent feed for a catalytic reformer and a middle distillate fraction that is a... 

The H-Coal process produces approximately 3-3.5 barrels of liquid product for each ton of coal.42 Tests showed that the process is best suited for high-volatile bituminous coal the use of low-rank coals significantly reduced throughput and distillate yields. The successful performance of the ebullated bed reactor in the H-Coal process led to its later use in two-stage liquefaction systems. 

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