GB602376A - Improvements in the distillation of mixtures of coal and hydrocarbon oil - Google Patents

Abstract

<PICT:0602376/III/1> Finely divided coal, peat or lignite is mixed with an acylic hydrocarbon oil having an upper boiling point between 700 DEG and 800 DEG F. to form a suspension containing at least 50 per cent of coal. The suspension is continuously passed through a distillation zone maintained at an elevated temperature not exceeding 800 DEG F. The distillate and coked residue are separated, and at least a part of the latter is reacted with steam to produce water-gas which is used to make a synthetic hydrocarbon oil. A fraction of this synthetic oil with an upper boiling point between 700 DEG and 800 DEG F. is separated and utilized in the mixing zone. The distillate from the distillation zone is preferably cracked or reformed, and gasoline fractionated from the product. Motor fuels may also be separated from the synthetic oil. Ground coal from line 1 is mixed in line 2 with paraffinic oil boiling in the range 300 DEG -800 DEG F. which has been made in later stages of the continuous process and is supplied through line 17. Hot ash and coke are then introduced through lines 5 and 6 respectively, and the mixture passes into distillation zone 4 where a temperature of about 700 DEG to 800 DEG F. is maintained. The "hindred settling" technique is employed in zone 4, the particle size of the coal and the vapour velocity being adjusted so that the coal remains in the zone from 3 to 30 minutes. The distillation products are separated in separator 8 from whence the vapours are passed to cracking plant 11 and fractionating column 12. Gasoline is withdrawn through line 13; 8.0 barrels being obtained from 1 ton of coal. The bottom fraction may be supplied to the mixing line 2 through lines 16 and 17. The coked residue from separator 8 is introduced into line 19 through which flows steam and oxygen and, if desired, the gases from column 12. The mixture is conveyed to generator 21 where water gas is produced at a temperature in the range 1600 DEG -2500 DEG F., unconverted coke being withdrawn through line 6 to supply heat for the main distillation step. The water gas is separated from ash in separator 23, and passed to plant 25 where liquid hydrocarbons are synthesized. These are fractionated in column 27; light motor fuel being withdrawn through line 28, diesel fuel through line 29, and a fraction having an end boiling point of about 700 DEG to 800 DEG through line 30 and/or line 31; the latter fraction is supplied to mixing line 2 through line 17. The overhead gases from column 27 are either recycled to the synthesis plant or passed through line 38 into steam feed line 19.ALSO:Liquid hydrocarbons are produced from water gas at atmospheric pressure, or pressures up to 150 lbs./sq. inch (gauge) using a catalyst containing metallic cobalt, iron, nickel or copper, promoted with an oxide of chromium, zinc, aluminium, magnesium or the rare earth metals, and carried on kieselguhr, pumice, or hydrated silica and alumina gel. Optimum gas composition ranges from 0.5 to 2.5 volumes of hydrogen per volume of carbon monoxide. The reaction temperature is between 350 DEG and 430 DEG F. with catalysts containing cobalt and magnesia, and between 550 DEG and 650 DEG F. with those containing iron. Fluid catalyst technique may be employed.