| 摘要 |
1528470 Coal pretreatment for fluid bed reactors UNION CARBIDE CORP 23 Dec 1975 [27 Dec 1974] 52598/75 Heading C5E A method of reacting coal particles in a fluidized-bed reactor wherein the coal particles are pre-conditioned to substantially prevent agglomeration of the coal particles in the fluidized-bed comprises (a) preheating a dense flow (defined) of said particles in the absence of oxygen at a first temperature for a preheat time sufficiently brief to avoid significant agglomeration of said particles; (b) preheating an oxygen-containing gas to a temperature substantially equal to said first temperature; (c) introducing said preheated particles and said preheated oxygen-containing gas into a vertical standpipe in an upwards direction, said gas having a superficial gas velocity greater than the free fall velocity of the largest of said coal particles, the amount of oxygen in said gas and said superficial gas velocity being controlled so that said oxygen is substantially consumed exothermically at a second temperature greater than said first temperature and within the plastic transformationtemperature of said particles; (d) reacting said particles with a reagent in said fluidized bed. Significant devolatilization of the coal in the oxidation standpipe is avoided by appropriate selection of preheat temperatures for the coal and the oxygen-containing gas, or by injection of an inert fluid (e.g. water) into the standpipe. The first (preheat) temperature of the coal is preferably 280-420‹ C., and the second temperature in the standpipe is 380-480‹ C. during oxidation, falling to 300-400‹ C. when the oxygen has been consumed. The process is particularly applicable as a pretreatment for fluidized bed hydrocarbonization of sub-bituminous or bituminous coals. |
