Patent GB-363711-A (GB)
Title: Improvements in the oxidation of hydrocarbons
Filed: 1930-09-19
Abstract: The oxidation of solid or liquid hydrocarbons to obtain products such as alcohols, aldehydes, ketones, and non-aromatic carboxylic acids is preceded by a purification treatment with hydrogen at temperatures between 150-450 DEG  C., and under pressures of from 5 to 500 atmospheres in order to remove sulphur compounds therefrom.  The hydrogenation is preferably conducted under such mild conditions that no substantial proportion of the unsaturated hydrocarbons present is hydrogenated.  Instead of pure hydrogen, gases containing or supplying hydrogen, for example, mixtures of carbon monoxide with steam, or of gaseous hydrocarbons such as methane with steam, may be used for the hydrogenation.  Suitable initial materials are aliphatic or naphthenic solid or liquid hydrocarbons such as petroleum middle oils, mineral or brown coal tars or low temperature carbonization tars, or hydrocarbons obtained from the hydrogenation products of coals, petroleum residues, and the like.  The hydrogenation may be effected in the presence of catalysts comprising metals of groups 4 to 7 of the periodic system or oxides or other compounds thereof, for example, molybdenum or molybdenum sulphide; cobalt or cobalt sulphide may also be used.  These catalysts may be activated with sulphides and/or deposited on carbon or charcoal or compounds, particularly oxides, of the alkaline earth metals or earth metals.  In addition to the desulphurization treatment with hydrogen, a further desulphurization with the usual agents, for example, sulphuric acid or liquid sulphur dioxide, may be carried out before the subsequent oxidation.  The oxidation may be effected either in the liquid phase at temperatures from about 100 to 200 DEG  C. with oxidizing agents such as air, oxygen, or nitrogen oxides, and in the presence of catalysts such as stearates, cinnamates, or other salts of manganese, barium, or mercury, or in the gaseous phase at temperatures from 200-400 DEG  C., preferably with air, and in the presence of catalysts such as the oxides of molybdenum, chromium, bismuth, uranium, or mixtures thereof.  According to examples (1) American gas oil is treated with hydrogen at 350 DEG  C. under 150 atmospheres pressure in presence of a mixture of nickel and molybdenum sulphides precipitated on carbon and is subsequently blown with air in the presence of manganese stearate, carboxylic acids, alcohols, and ketones being obtained; (2) an oil fraction obtained by cracking brown coal low temperature carbonization tar is passed under a partial pressure of hydrogen of 200 atmospheres at 360 DEG  C. over a mixture of zinc oxide, molybdenum oxide, and magnesium oxide deposited on carbon; other catalysts comprising oxides or sulphides of elements of groups 3, 4, or 6, if desired, together with zinc oxide and/or magnesium oxide may be used.  The hydrogenation product is blown with air at 160 DEG  C. in presence of manganese naphthenate.  The acids thus formed may be separated from the product and the remainder, if desired, with the addition of fresh initial material, again hydrogenated and oxidized, and (3) a distillate from Pennsylvanian crude oil is treated as in example (2).