PROCESS FOR PURIFYING CRUDE GAS PRODUCED BY THE GASIFICATION OF SOLID FUELS

摘要

1499779 Scrubbing gases METALLGESELLSCHAFT AG 5 May 1975 [5 Feb 1975] 18832/75 Heading C5E In a process for the purification of crude gas produced in a gas producer 1 by the pressure gasification of solid fuel with steam and oxygen, the gas, which leaves the producer at a temperature of 400-700‹ C. and contains dust and hydrocarbons, is sprayed in a cyclone scrubber 6 with 0À5-6 litres water per scm. of gas, the temperature of the water being 160-300‹ C. whereby dust and hydrocarbons are removed, and the gas is cooled and saturated with water; the gas 14 leaving the scrubber is then passed to a second scrubbing stage where it is further scrubbed with water at 160-300‹ C., at a rate of 0À1-0À3 litres per scm. of gas. In the embodiment shown, the second scrubbing stage is performed in a radial flow scrubber 16, but this may be replaced by a Venturi type scrubber. The scrubbing stages are performed under the same pressure (4-150 bar) as the gasification reaction. As shown, the dust and tar containing water from the cyclone scrubber 6 is passed to a tar separator 11, from which dust containing heavy tar is recycled to the gas producer and dust free water which may also contain some hydrocarbons is passed via line 10 to the pressure heater 9 which feeds hot water to the cyclone scrubber 6. Water 17 from the heater 9 is passed to the radial flow scrubber 16, which is of the type described in 29917/73. In a further embodiment (Fig. 3, not shown) a conventional desulphurizer is incorporated into the purifying system, between the first cyclone scrubber and the second scrubbing stage.