| 摘要 |
<PICT:0593630/IV/1> A process for obtaining an optimum yield of gasoline from coal includes the steps of carbonisation of the coal as a fluidised mass, conversion of the coke formed to water-gas and a Fischer-Tropsch synthesis of part of the water-gas while the remainder of the water-gas is used as a source of hydrogen for adjustment of the H2/CO2 ratio in the synthesis step and for the hydrogenation of the tar produced by the carbonisation step. Powdered coal passes through a preheater 3 to the coker 12 as a fluidised mass. Gaseous products from the coker 12 pass partly to a condenser 30, partly to the preheater 3 and then to a tar and gasoline recovery unit 42. Olefins in the gaseous products leaving the unit 42 are polymerized or alkylated and gaseous residues may be burnt to supply some of the heat for the process. Coke is withdrawn from the coker 12, air admitted by the pipe 16 and a suspension of coke passes to the heater 60 where the coke undergoes partial combustion raising its temperature to between 1800-2400 DEG F. Some of the heated coke is returned to the coker 12 and the remainder passes to the water-gas generator 80, steam being admitted by the pipe 75. Sulphur compounds are removed in a unit 83 and a portion of the water-gas passes to the synthesis reactor 86, additional hydrogen being added by a line 90 if necessary. Normally, liquid hydrocarbons are recovered in a unit 93 and may be fractionated, the fractions being reformed or cracked in a unit 96. Another portion of the water-gas passes to the burner 124 where CO is converted to CO2 by controlled oxidation, the CO2 being scrubbed out and the hydrogen used in the synthetic reactor 86 or tar hydrogenation unit 101 which receives the tar separated from the gaseous products of the carbonisation step. Normally, gaseous products from the unit 101 mix with those from units 93 and 96 and pass to a unit 121 where they are treated with steam in the presence of a catalyst to form a mixture of CO and H2 which passes to the burner 124 and becomes an additional source of hydrogen. Specification 586,391, [Group XII], is referred to.
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