GB711426A - Improvements in or relating to the distillation of oil bearing minerals - Google Patents

Abstract

711,426. Distilling oil shale. STANDARD OIL DEVELOPMENT CO. April 16, 1951, No. 8873/51. Class 55 (1) In a process for distilling oil shale, particulate shale as a fluidized mass is heated by indirect heat exchange with a-fluidized mass of burning or burned spent shale. As shown in Fig. 1 raw shale is fed from a hopper 1 to a header 25 arranged with a vessel 10 and communicating with tubes 20 which extend through the vessel 10 and are surrounded by a fluidized bed of burning spent shale confined within the vessel 10, fluidizing gas, for example, steam or tail gas, is introduced into the tubes 20 by nozzles 23 and the shale is distilled as a fluidized bed formed within the tubes 20 and the header 25. The shale is heated to between 800-1400‹ F. in its passage down the tubes, distillation vapours and gases leave through line 29 or through line 7 to preheat the incoming raw shale in the hopper 1. Spent shale from the bottom of the tubes 20 passes into a hopper 30 and then through a valve 34 into a line 36 where it is entrained by air entering the line 36 and conveyed to the vessel 10 and into the fluidized bed of burning shale around the pipes 20. Combustion gases leave by line 38 and coarse particles of spent shale are withdrawn through line 40. The amount of oxygen in the air supply is controlled to give the mass of burning spent shale a temperature of between 1100-1600‹ F. and the rate of withdrawal of the spent shale from the hopper is controlled by the valve 34 to give the shale in the tubes 20 a distillation period of 2-10 minutes. In a modification the zone in which the spent shale is combusted may be subdivided by a number of horizontal perforated partitions and the liquid products of the distillation may be withdrawn from a middle portion of the tubes 20. In further modifications, the spent shale is combusted in a burner arranged below a distillation vessel and hot burned spent shale is passed upwardly suspended in the combustion gases through tubes passing through the distillation vessel and surrounded by a fluidized bed of shale undergoing distillation. The distillation vessel may have horizontal perforated partitions and spent shale is fed from the bottom of the vessel to the burner. Spent shale may be separated from the combustion gases after passing through the tubes in the distillation vessel and be returned to the burner. Specification 644,013 is referred to.