| 摘要 |
510,513. Synthesis of hydrocarbons. METALLGES. AKT.-GES. Dec. 2, 1937, No. 33360. Convention date, Dec. 2, 1936. [Class 2 (iii)] In a process for the catalytic conversion of gases containing carbon monoxide and hydrogen into hydrocarbon containing more than 2 carbon atoms in the molecule a t temperatures between 150 and 265‹C., dilute synthesis gas is applied to a contact furnace under a pressure greater than 2 atmospheres, at least a portion of the hydrocarbon products are separated from the end gas which is recycled to the inlet of the contact furnace and fresh gas rich in carbon monoxide and hydrogen is admitted beyond the point of admission of the recycled end gas so that the gas undergoing the catalytic conversion always contains more than 20 per cent. of inert constituents. The catalysts employed are those known to be suitable for the Fischer - Tropsch benzine synthesis at atmospheric pressure, e.g., cobalt 33 per cent., thorium oxide 5 per cent. and kieselguhr 61 per cent. The incorporation of the fresh gas may be effected approximately midway of the reaction zone or distributed over a number of points. In this way greater uniformity of reaction is ensured and local overheating is avoided. In the drawing A denotes a contact furnace with spaced sets of contact mass A', A<2>, A<3>, A<4>. Dilute synthesis gas enters at B. Reaction products are separated at D and withdrawn at E. Part of the uncirculated gas is recycled to B and part withdrawn at G. Fresh gas is introduced at H, I, K. Other diluents may be added to the reacting gases, e.g., methane, carbon dioxide, water, alcohols or higher hydrocarbons. Substances which occur as less desirable products of the synthesis may be employed as diluents. Addition of benzine vapour as diluent increases the life of the catalyst by extracting high boiling substances which impair its activity. The proportion of diluents in the gases is greater the greater the working pressure. The synthesis may be subdivided into stages, separation of the products occurring between stages. The Specification as open to inspection under Sect. 91 comprises generally the catalytic synthesis of hydrocarbons from mixtures of oxides of carbon and hydrogen containing gases containing more than 20 per cent. of diluents. The use of end gases from a methanol synthesis or from a Fischer-Tropsch benzine synthesis at atmospheric pressure is described. Addition of gas-oil vapours as diluent is referred to. The use of pressure in the reaction together if desired with cooling is stated to facilitate separation of products at the end of the synthesis-the hydrocarbons becoming liquid and carbon dioxide being readily washed out. The pressure is preferably so high that the partial presence of reacting gases is the same as in the normal synthesis at atmospheric pressure with gases nil in CO2 and H2. Operation in stage and regeneration of the catalysts are referred to. Two examples are given illustrating modes of operation. This subjectmatter does not appear in the Specification as accepted. |
