GB334193A - Improvements in the manufacture and production of valuable products from gaseous acetylene hydrocarbons or aldehydes - Google Patents

Abstract

334,193. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Feb. 23, 1929. Amines; nitriles; heterocyclic nitrogen compounds.-Nitrogenous products are obtained by passing acetylene, or mixtures thereof with its homologues, together with ammonia and/or amines, and if desired with steam, over heated condensation catalysts, and then conducting the products, without isolation, together with hydrogen over metallic hydrogenating catalysts. Instead of acetylene, aliphtic aldehydes may be employed, or mixtures thereof with the acetylene hydrocarbons. The condensation and hydrogenation may be effected simultaneously by mixing the two catalysts and introducing the hydrogen at the beginning of the operation. The condensation catalysts comprise compounds of aluminium or of metals, except arsenic, having a specific gravity above 4.4 and belonging to the second to the seventh periodic groups; hydrogenating catalysts mentioned are metals of the iron group, copper and platinum. Industrial gas mixtures containing hydrogen and acetylenic hydrocarbons may be employed, e.g. coke-oven gas or gas mixtures obtained by passing coke-oven gas or a mixture of methane and hydrogen through a high tension electric arc. The condensation is effected at a temperature of 250‹- 500‹ C., whilst the hydrogenation preferably takes place at a lower temperature, e.g. 150- 250‹ C. When producing hydrogenated heterocyclic bases from mixtures of acetylene with ammonia and/or an amine in the presence of steam, the gas mixture is preferably passed over the catalyst at a speed of at least 10 litres of the hydrocarbon per hour per litre of the catalyst. According to the examples, (1) acetylene, ammonia and hydrogen are passed at 350‹ C. over a mixture of equal parts by weight of zinc oxide and thorium oxide precipitated on silica gel and then over finely-divided nickel on silica gel at 150‹ C. ; the condensate consists mainly of piperidine and monoethylamine; the addition of steam increases the proportion of the piperidine; (2) ammonia and acetaldehyde vapour mixed with hydrogen are led at 350‹ C. over zinc oxide mounted on silica gel incorporated with thorium oxide and then at 150‹ C. over nickel on silica gel; the product mainly comprises piperidine and a small quantity of amines; (3) ammonia, acetylene, hydrogen and the vapours of acetaldehyde and ethylamine are passed at 400‹ C. over a mixture of zinc oxide, thorium oxide and metallic cadmium on silica gel and then at 120‹ C. over nickel on silica gel; the condensate consists chiefly of ethylamine and piperidines, together with small quantities of acetonitrile, propionitrile, pyridine bases and pyrrol derivatives; (4) aniline vapour, acetylene and hydrogen are conducted at 300‹ C. over a mixture of chromic oxide, aluminium oxide and zinc oxide on silica gel and then at 200‹ C. over nickel on silica gel; the condensate mainly comprises hydrogenated quinolines, chiefly tetrahydroquinoline; (5) acety. lene, hydrogen, methane and nitrogen (obtained by treating a mixture of methane and hydrogen in the electric arc and containing a small amount of allylene and diacetylene) is mixed with ammonia and passed at 380‹ C. over a mixture of zinc and chromic oxides and then at 150‹ C. over activated nickel; on cooling, a product consisting of primary ethylamine and acetonitrile is obtained. Specifications 109,983, 265,960, 321,177 and 332,623 are referred to. The Provisional Specification describes the use of any acetylene hydrocarbon.