Formation of sulphur compounds during the hydrodenitrogenation of aniline, cyclohexylamine, benzylamine, and 2-phenylethylamine on a nickel-tungsten catalyst in the presence of hydrogen sulphide
Hydrodenitrogenations of aniline, cyclohexylamine, benzylamine, and 2-phenylethylamine were performed on a sulphided nickel-tungsten catalyst at 300°C in an autoclave filled with hydrogen in the absence and in the presence of hydrogen sulphide. Due to the presence of hydrogen sulphide the degree of conversion increased from 0.9 to 3,6% for aniline and from 72 to 99% for benzylamine, and the fraction of neutral substances increased from 2.4 to 7% for cyclohexylamine and from 5.0 to 8.9% for 2-phenylethylamine. The neutral fractions contained cyclohexanethiol, thiobenzamide, 2-phenylethanethiol, and other sulphur compounds giving evidence that the increased degree of conversion of the amines was due to the hydrogen sulphide taking direct part in the chemical reaction.