GB680171A - Improvements in or relating to the treatment of carbonaceous materials - Google Patents

Abstract

680,171. Distilling solid carbonaceous materials. STANDARD OIL DEVELOPMENT CO. Aug. 16, 1950 [Nov. 1, 1949], No. 20344/50. Class 55 (i). In a fluidized carbonization process wherein the fluidizing gases are free from constituents reacting exothermically with the materials being carbonized, the materials to be carbonized are preheated to a temperature of at least 400‹F., but substantially below the temperature of carbonization and the temperature of carbonization is maintained exclusively by the preheating and heat evolved during the process of carbonization. Particulate solids, such as finely divided coal, are fed from a hopper 1 to a preheater 2 and preheated to a temperature of between 400-800‹F. before passing to a carbonization zone 10 through line 4, fluidizing gases being supplied to the zone through a line 6. In starting up the process oxygen and hot gases may be supplied through a line 16 until the necessary temperature is obtained. Hot distillation residue from the zone 10 is circulated via line 46 through the preheater 2 and a proportion may be added to the preheated charge through line 42, any surplus residue being withdrawn through line 43. In a modification the solids feed is also preheated by indirect heat exchange with the hot gaseous distillation products. Carbonization temperatures of 800‹-1,200‹F. and pressures up to 500 lbs. per sq. inch are employed. The temperature in the carbonization zone may be controlled by the provision of a cooling coil therein. The time of residence of the solids in the carbonization zone is such that it is about five times the minimum coking time of the particular charge, so that at least 80 per cent of the charge will be held in the carbonization zone for a longer time than the minimum coking time.