GB766095A - Improvements in or relating to low temperature tar - Google Patents

Abstract

766,095. Gas manufacture. KOPPERS CO., Inc. March 22, 1955 [May 4, 1954], No. 8325/55. Class 55 (2). Low-temperature tar is mixed with a coal charge and subjected to high-temperature coking, whereby a portion of the lowtemperature tar is recovered as high-temperature. The low-temperature tar, which is produced by coking between 450‹ and 700‹ C., is mixed in the proportion by weight of 1 to 10 per cent of tar to 99 to 90 per cent of a coal suitable for high-temperature coking, the mixing preferably being effected outside the hightemperature coking-chambers. The mixing may be effected during the final crushing of the coal, and the coal may be of a high volatile type, or may be a blend of coals. The retorts may be horizontal, vertical or inclined. The lowtemperature tar may be mixed with char, from the low-temperature coking, and with the coal; the high-temperature coking being in the range 800‹ to 1150‹ C. In an example, 200 tons of char and 36 tons of tar from the low-temperature coking are mixed with 800 tons of highvolatile coal, the tar yield from the hightemperature coking being in excess of that from the coal alone by about one half of the weight of the low temperature tar used.