thiophene Thiophene (thiofurfurane) has a molecular weight of 84.14 and contains 57.10% of carbon, 4.79%of hydrogen and 38.11% of sulfur. It occurs naturally in the pyrolysis products of coal and is present at about 1-2% in Benzole the aromatic extract of coal or coke oven gas. It also occurs in technical benzene from which it is quite difficult to separate. It is prepared commercially by dehydrogenating butane with sulfur followed by cyclization with sulfur. It can also be produced by passing a mixture of acetylene and hydrogen sulfide over hot bauxite or nickel hydroxide. It can be separated by from benzene by gas chromatography but requires a high efficiency capillary column and a dispersive stationary phase.
Author: RPW Scott
Book:Preparative Chromatography
Section:Preparative Alternative-Techniques Moving-Bed-System Benzene-from-Coal-Gas
solute (A). The main product, benzene, is represented by solute (B), and the high boiling aromatics are represented by solute (C) (toluene and xylenes). An analysis of the products that were obtained are shown in figure 27. The material stripped form the top (section (1)) is seen to contain the alkanes, alkenes and naphthenes and very little benzene. The product stripped from the center section appears to be virtually pure benzene. The product from section (3) contained toluene, the xylenes and thiophen which elutes close to benzene. The thiophen, however, was only eliminated at the expense of some loss of benzene to the lower stripping section. Although the system worked well, Scott and Maggs found it experimentally difficult to set up and maintain production under constant operating conditions. The problems arose largely from the need to adjust the pressures that must prevent cross-flow. Without doubt, today, the system would be computer controlled. The simple system as described,
Preparative Alternative-Techniques Moving-Bed-System Benzene-from-Coal-Gas
