| 摘要 |
A process for autothermic gasification of solid fuels, preferably coal, in fine powdered form under excess pressure with a gas comprising oxygen, wherein <SL> <LI>(a) as a preliminary heat treatment step, the finely divided fuel first undergoes pyrolysis by direct contact with a flow of hot smoke gas, preferably reaching a final temperature of at least 450{C, most preferably a temperature in the range 600-750{C; the gases and vapours produced are separated and an intermediate brittle solid product is produced; <LI>(b) the flow of hot smoke gas used in step (a) is generated by combustion in the presence of the gases and vapours separated in step (a) and heat is extracted from said flow of hot gas before it is introduced into step (a) in order to generate the mixture of water vapour (or steam) and gas comprising oxygen required in the gasification step (c) below; <LI>(c) the intermediate brittle solid product produced in step (a) is converted to a fine powder and subjected to gasification in the presence of water vapour to produce synthesis gas rich in H<SB>2</SB> and CO. </SL> The synthesis gas produced by this process is suitable for use without the need for further purification in such processes as (i), most preferably, the direct reduction of pig iron; (ii) as a starting material for chemical and/or petrochemical processes or (iii) for the generation of electrical power using a CGST (Combined Gas/Stream Turbine) process. A catalyst such as potassium carbonate in finely divided form may be added to the gasification step in order to achieve high throughput rates at lower temperatures than in the absence of catalyst. |
