Hard coal, liquefaction

In the United States, whidi has the most attractive oil shale reserves, interest in oil shale development has waxed and waned. This is partly because the richest oil shale reserves, the Green River Formation in Colorado, Utah and Wyoming, are on lands owned mostly by the US government and therefore are not available for commercial development. Tracts of oil shale lands in the Green River Formation were leased for commercial development in 1974 and the decade between 1974 and 1984 represented the greatest activity ever in oil shale research in the USA. Since then, interest has diminished and hardly any oU shale research is presently being conducted. Understandably, the plentiful supply and low cost of petroleum has suppressed the commercialization of oil shale and other fossil fuel conversion processes (tar sand processing and coal liquefaction). 

The metal diborides, MB2, have two-dimensional networks of boron atoms in a hexagonal crystal symmetry. They are very hard, brittle, metallic conductors, and are chemically inert (especially TiB2 and ZrB2). Transition metal diborides are resistant against carbon at lOOO C and are therefore used to passivate steel in coal liquefaction equipment. The diboride alloys Zro.13Moo.87B2 (Tc=10K) and SC0.1Nb1.9B2 (7 = 6.6K) are superconductors. 

The liquefaction of lignite and hard coal into liquid hydrocarbons can be represented by the following equations (dry and ash-free basis), if we take a 1 1 mixture of n-decane and naphthalene as representative for all produced hydrocarbons ranging from gases to heavy oil ... 

For the remote and hard-to-access areas - support of the gas processing and liquefaction for further transportation or support of the coal gasification for areas with deposits of coal ... 

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