LIGNITE - A POSSIBLE NEW FEED.

This paper is concerned with the utilization of byproducts obtained during carbonization of lignite. In the carbonization process, crushed lignite is dried in a fluidized bed heated using the combustion gases of carry-over fines. The dried lignite is carbonized in a fluidized bed, partially heated by some char burn-off in the bed, the remaining heat being provided by burning off-gas in refractory flues around the bed. The product stream from the carbonization retorts is hot-cycloned to remove the remaining char, which joins the char from the retorts, for combustion in a cyclone boiler system. The gas stream is separated into a gas for combustion in the carbonizing retorts and a liquid feedstock for a byproduct recovery plant. The authors presents the preliminary design of a typical byproducts recovery plant. Results of a test program are presented along with optimal process parameters. Economic considerations are included.