GB637720A - Separating thiophene from benzoles by distillation - Google Patents

Abstract

<PICT:0637720/III/1> Thiophene is separated from benzole by first submitting it to fractionation to remove carbon disulphide and other compounds boiling below 80 DEG C., then separating a fraction boiling between 80 DEG and 85 DEG C., and finally rectifying the 80-85 DEG C. fraction in a high-efficiency column divided into several sections; thiophene being withdrawn from the base of the first section, and benzene from the head of the last. Crude benzole is fed from tank A into column B where it is freed from compounds boiling below 80 DEG C. The bottoms from column B are supplied to column C through pipes 6 and 7, by means of steam-heated jacket T. The vapours of the 80-85 DEG C. fraction are withdrawn from the head of column C, partly condensed in the heater M of column-section E, and submitted to complete condensation in condenser R1. Part of the condensate is returned as reflux to the head of column C; the remainder is withdrawn through measuring device 11, supplied to tank D, and rectified in column sections E, F, G which are arranged to function as if they were superposed. The circulation of the reflux liquids from sections F and G is effected by steam-heated jackets L and K respectively. Benzene vapours are withdrawn from the head of section G, and condensed in condenser Q. Part of the condensate is returned to head of section G, and the remainder is removed from the system through measuring device N. Thiophene is withdrawn from the base of section E through pipe 22 and cooler P. Moderate vacuum is applied at outlet V of condenser Q and enables the vapours from the head of column C to supply, via heater M, all the heat required for column-sections E, F, G. Alternatively column C may be operated at a moderate pressure about atmospheric. Specification 441,518 is referred to.