| 摘要 |
In the hydrogenation of benzene, a preliminary purification for the removal of catalyst poisons is effected by treating the benzene with sulphuric acid (to remove thiophene), and subjecting it to fractional distillation until the distillate passing over becomes free from carbon disulphide. In an example, benzene is agitated with concentrated sulphuric acid, the acid layer is withdrawn, and the benzene is washed several times with water and then with a solution of sodium bicarbonate, carbonate or hydroxide, fractionally distilled until the distillate passing over no longer yields a precipitate with cyclohexylamine (test for carbon disulphide), and then hydrogenated at 180 DEG C. under 34-120 atmospheres pressure of hydrogen in the presence of a nickel catalyst prepared by the process described in U.S.A. Specification 1,628,190. Comparative examples show the effect of removing thiophene only by the sulphuric acid treatment, and of removing carbon disulphide only by the fractional distillation. If desired, the fractional distillation may precede the sulphuric acid treatment. Specifications 258,576 and 315,439, [both in Class 91], are referred to.
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