| 摘要 |
A process is disclosed for gasifying solid coal particles in a rotary kiln that produces simultaneously and continuously two distinctly different fuel gas streams from the opposite ends of a single kiln. A relatively low temperature gas is discharged from the solids inlet end of the kiln, which contains substantially all tars produced by the process. A second of the gas streams is discharged from the solids discharge end of the kiln at approximately 1,900 DEG F. and substantially tar-free. Heat is recovered from this tar-free gas after only a simple cleaning of particulate matter, as may be provided by a cyclone separator. The discharge of gas out the solids inlet end of the kiln and the gas discharged out the solids discharge end of the kiln, is adjustably proportioned relative to each other so that at least some high temperature tar-free gas will mix inside the kiln with the lower temperature tar-containing gas, in an amount sufficient to keep such mixed gases at a temperature high enough to avoid the tars condensing on equipment surfaces. Several process parameters are disclosed for adjusting the proportion of the gas flows out each end of the kiln to maintain the aforesaid condition of both gas streams. |
