GB439036A - Improvements in or relating to cracking coal tar oils and distillates - Google Patents

Abstract

<PICT:0439036/IV/1> In the production of motor spirit by cracking coal tar oils and distillates in the vapour phase the naphthalene formed synthetically or released in the process is separated from the liquid residues. Coal oil distillate is passed at 400 DEG F. into a tube still A in which it is heated to 780--800 DEG F. and thence to an evaporator B in which tars are separated out at the bottom while the vapours are passed to a converter C in which they are heated to 1000--1200 DEG F. The cracked vapours cooled by admixture with make-up stock supplied through a pipe F or by passage through a cooler E enter a dephlegmator D, the upper end of which is maintained by stream of make up stock entering through a pipe G at 265 DEG F. or over so that the naphthalene is carried over by the vapours while naphthalene-free residues collect in the bottom of the tower and are returned through a line H to mix with the crude stock. The vapours then pass to a dephlegmator 1 in which the naphthalene is condensed and collects at the bottom where it is maintained liquid by a coil L and is removed to a cooler K while the gasolene vapours pass off through a purifier M to a cooler N. In a modification, the tower G is maintained at about 250 DEG F. and the naphthalene is condensed and separated out as an intermediate fraction.ALSO:<PICT:0439036/III/1> Motor spirit is obtained by cracking coal tar oils and distillates in the vapour phase, separating the naphthalene formed synthetically or released in the process from the liquid residues, and returning the residues to mix with the oils entering the plant. Coal oil distillate is passed at 400 DEG F. into a tube still A in which it is heated to 780--800 DEG F. and thence to an evaporator B in which tars are separated out at the bottom while the vapours are passed to a converter C in which they are heated to 1000-1200 DEG F. The cracked vapours cooled by admixture with make-up stock supplied through a pipe F or by passage through a cooler E enter a dephlegmator D the upper end of which is maintained by stream of make up stock entering through a pipe G at 265 DEG F. or over so that the naphthalene is carried over by the vapours while naphthalene free residues collect in the bottom of the tower and are returned through a line H to mix with the crude stock. The vapours then pass to a dephlegmator I in which the naphthalene is condensed and collects at the bottom where it is maintained liquid by a coil L and is removed to a cooler K while the gasolene vapours pass off through a purifier M to a cooler N. In a modification the tower G is maintained at about 250 DEG F., and the naphthalene is condensed and separated out as an intermediate fraction.