Patent GB-653495-A (GB)
Title: Production of gaseous or vaporous fuels from solid carbonaceous material
IPC: C10J3/46
Filed: 1946-07-29
Abstract: 653,495. Coking; gas-producers. STANDARD OIL DEVELOPMENT CO. July 29, 1946, No. 22566. [Class 55(i)] In a process for producing gaseous or vaporous fuels from solid carbonaceous materials, e.g. coal, coke, peat, tar sands, oil shales and heavy oil residues, the latter being adsorbed on inert granular material, the material is subjected to at least three successive and different heat treatments in fluidized beds in separate zones, the fluidizing gases passing upwardly and the products being recovered overhead; the total hot gases and entrained solids from one zone is passed directly to the zone next above; and the heat required in at least one of the thermal treatment zones is supplied at least in part as the sensible heat of residual solids transferred thereto from a zone operated at a higher temperature. In Fig. 1, finely divided carbonaceous solids are supplied by known means through line 1 to a preheating zone 4, the solids being fluidized by flue gases passed from the off-take line 11, 12 to the line 1 by a blower 3, the preheated solids being transferred to a distillation chamber 17 which is heated by residues, passed through the pipe 33, from the combustion zone 8, which zone is supplied with coke from the chamber 17 through the pipes 26, 30. The combustion gases from the zone 8 pass directly through the. fresh material in the zone 4, and, assisted if desired by additional gas from a line 5, raise the material rapidly to a sub-distillation temperature of 300‹- 500 ‹F. The combustion gases and entrained solids pass into a gas-solids separator 10, the solids 'being returned to the process through the pipe 14. The cooled gases pass through a waste-heat boiler 11a and are discharged at 12 or returned to the process by the blower 3. The flow of preheated material to the distillation chamber 17 may be assisted by the admission of fluidizing gas at 16. Fluidizing gas is supplied below the grid 19 through line 21, and a mixture of distillation products and fluidizing gas is withdrawn through a gas-solids separator 22, with a return 24 for the solids, and passed, for example, to a shale-oil processing plant, by a pipe 23. Coke is withdrawn through the pipe 26 and is further fluidized by gas admitted at 27. Air, heated to above the ignition temperature of the coke by heat exchange at 35 with spent material passing from the combustion zone 8 through a pipe 34, is admitted at 29 to the pipe 30 conveying the coke from the chamber 17 to the space beneath the grid 31 of the zone 8. The separator 10 may be dispensed with if part of the flue gases are recirculated. Air may be supplied to the chamber 17 at 21 to effect a partial combustion therein, or steam or a mixture of steam and air may be admitted to utilize the chamber 17 as a water-gas or producer-gas generator. Alternatively, the zone 8 may be operated as a gas. generator by admitting steam and air, either simultaneously or alternately through the line 29. In a modification, the process is carried out in three zones at different levels in a single chamber, the upper preheating zone, into which the raw material is fed, being divided from the combustion zone by a grid, the latter zone being separated from the carbonization zone by a transverse plate. The fuel gas passes through a gas-solids separator, beneath the plate, to an offtake pipe. The heat for the carbonizing is provided by the hot residues gravitating through a pipe from the combustion zone to the carbonizing zone, and the coke is delivered by a stream of preheated air to the bottom of the combustion zone. The functions of the three zones may be altered, or reversed, e.g. the lower zone may be the combustion zone, the upper zone the carbonizing zone, and the middle zone the gas-generating zone. Specification 586,992 is referred to.