| 摘要 |
1,204,683. Production of dimethyl sulphide. SOC. NATIONALE DES PETROLES D'AQUITAINE. 11 Dec., 1967 [21 Dec., 1966], No. 56269/67. Heading C2C. A process for the manufacture of dimethyl sulphide in two stages comprises reacting methanol with hydrogen sulphide in the first stage to form methyl mercaptan and then reacting the latter with methanol in the second stage to form dimethyl sulphide, the proportion of methanol in the second stage being regulated to a value such that the reaction product of the second stage does not contain more than 5% of methyl mercaptan. The major part of the methanol used in the second stage is generally derived from a portion containing methanol which has served for absorbing the products formed during the first stage of the process and from which the major part of the lightest sulphur compounds it contained have been removed, these being fed separately to the second stage as the crude methyl mercaptan component. The mixture rich in methyl mercaptan and the portion containing methanol are generally admitted to the second working stage at rates of flow such that during the second stage there are 1 to 1.25 mols. of methanol per mol. of methyl mercaptan. The reaction in the first stage is usually carried out at a temperature of from 300‹ to 350‹ C. under a pressure of 1.5 to 3.5 bars absolute and with aluminium oxide together with a small portio of sodium oxide as catalyst. The reaction in the second stage is generally carried out at a temperature between 300‹ and 330‹ C., 1À5-3À5 bars absolute and with pure aluminium oxide as catalyst. |
