Patent GB-364106-A (GB)
Title: Improvements in the manufacture and production of hydrocarbons not saturated with hydrogen and hydrogen from gas mixtures containing hydrocarbons
IPC: C07C2/00
Filed: 1930-08-20
Abstract: In the conversion of mixtures of gaseous hydrocarbons into hydrocarbons poorer in hydrogen and hydrogen at elevated temperatures, the initial material is treated in stages at successively increased temperatures so that the hydrocarbons which do not at first participate in the reaction are converted in the subsequent stage or stages, temperatures up to 1000 DEG  C. being employed in those stages in which mainly hydrocarbons having two or more carbon atoms in the molecule are converted, while temperatures above 1000 DEG  C. may be employed in the stages in which mainly methane is converted.  The lower the boiling point of the initial material, the higher are the reaction temperatures required, and olefines are produced at lower temperatures than aromatic hydrocarbons; the initial materials may be cracking gases, natural gases, the waste gases from the destructive hydrogenation of coals tars and mineral oils, and low temperature carbonization gases, or fractions from these gas mixtures.  The thermal treatment is carried out in chambers provided with continuously or periodically heated heat-exchanging filling material, e.g. coke, or siliceous substances, or fireclay, or chromium alloys, or with catalysts, such as difficulty reducible metal oxides, or with both.  The gases to be worked up may be mixed with steam, carbon dioxide or air, whereupon the converted gases may contain hydrogen and carbon monoxide if the reaction is carried out in a producer filled with coke.  To obtain a gas as rich as possible in hydrogen, the process is caused to proceed periodically by carrying hot blasting of the coke separately from the hydrocarbon conversion.  The products of each stage are preferably separated before the gases are passed to the next stage, and the methane-containing gas mixture left after the last of these stages, if desired without separating the unsaturated hydrocarbons, may be subjected to a catalytic treatment in the p  presence of steam in excess, air, or oxygen, at a temperature not above that of the previous reaction, so that the aromatic hydrocarbons present are largely unchanged, while the methane is converted to carbon monoxide and hydrogen; suitable catalysts for this last reaction are nickel and nickel oxide which have been actuated with aluminium or magnesium oxide, or two catalysts such as nickel and iron may be employed successively, so that the carbon monoxide formed is converted to carbon dioxide by the oxygen-containing gases present.  The treatment may be carried out under elevated pressure e.g. 20 to 50 atmospheres or more.  It is preferable to desulphurize the gases before working up into aromatic hydrocarbons, in order to prevent the deposition of coke. In the examples:--(1) A gas mixture obtained by the destructive hydrogenation of coal is mixed with an equal volume of steam, and passed at 700 DEG  C. over zinc oxide.  Water is separated, then the unsaturated hydrocarbons are removed by cooling to -50 DEG  C. Ethylene is washed out by means of bromine from the non-condensed gases, which are then led at 900 DEG  C. through a producer filled with coke.  Aromatic hydrocarbons, hydrogen and carbon black are obtained.  (2) A gas mixture obtained by the destructive hydrogenation of brown coal tar is passed through 4 producers filled with coke at temperatures of 750 DEG  C., 800 DEG  C., 850 DEG  C., and 900 DEG  C.  After each stage the unsaturated hydrocarbons are removed, and the residual gas is led together with an excess of steam over a catalyst consisting of aluminium oxide and nickel, the methane being converted to hydrogen with partial formation of carbon monoxide and dioxide.ALSO:In the conversion of mixtures of gaseous hydrocarbons into hydrocarbons poorer in hydrogen and hydrogen at elevated temperatures, the initial material is treated in stages at successively increased temperatures so that the hydrocarbons which do not at first participate in the reaction are converted in the subsequent stage or stages, temperatures up to 1000 DEG  C. being employed in those stages in which mainly hydrocarbons having two or more carbon atoms in the molecule are converted, while temperatures still higher than 1000 DEG  C. may be employed in the stages in which mainly methane is converted.  The lower the boiling point of the initial material, the higher is the reaction temperature required, and olefines are produced at a lower temperature than aromatic hydrocarbons.  The initial materials may be cracking gases, natural gases, the waste gases from the destructive hydrogenation of coals, tars, and mineral oils, and low temperature carbonization gases, or fractions from these gas mixtures.  The thermal treatment is carried out in chambers provided with continuously or periodically heated heat-exchanging filling material, e.g. coke or fireclay or siliceous substances or chromium alloys, or with catalysts, such as difficulty-reducible metal oxides, or with both.  The gases to be worked up may be mixed with steam, carbon dioxide, or air, whereupon the converted gas may contain hydrogen and carbon monoxide if the reaction is carried out in a producer filled with coke.  To obtain a gas as rich as possible in hydrogen, the process is caused to proceed periodically by carrying out the hot blasting of the coke separately from the hydrocarbon conversion.  The products of each stage are preferably separated before the gases are passed to the next stage. The resulting unsaturated hydrocarbons may be subjected to a polymerization or condensation, if desired with other substances, preferably in the presence of such a catalyst as aluminium chloride, or they may be converted to alcohols or glycols.  After the treatment in stages at successively higher temperatures, the resulting gas mixture containing methane, if desired without separating the unsaturated hydrocarbons, is subjected to a catalytic treatment in the presence of steam in excess, air, or oxygen, at a temperature not higher than that of the previous reaction, so that the aromatic hydrocarbons present are largely unchanged while the methane is converted to carbon monoxide and hydrogen; suitable catalysts for this last reaction are nickel and nickel oxide which have been activated with aluminium or magnesium oxide, or two catalysts such as nickel and p  iron may be used successively, so that the carbon monoxide formed is converted to carbon dioxide by the gases containing oxygen present.  The treatment may be carried out under elevated pressure, e.g. 20 to 50 atmospheres or more.  It is preferable to carry out a desulphurization before working up into aromatic hydrocarbons, in order to prevent the separation of coke. In the examples, (1) a gas mixture obtained by the destructive hydrogenation of coal is mixed with an equal volume of steam and passed at 700 DEG  C. over zinc oxide.  Water is separated, then the unsaturated hydrocarbons are removed by cooling to -50 DEG  C. Ethylene is washed out by means of bromine from the non-condensed gases, which are then led at 900 DEG  C. through a producer filled with coke.  Aromatic hydrocarbons, hydrogen, and carbon black are obtained.  (2) A gas mixture obtained by the destructive hydrogenation of brown coal tar is passed through four producers filled with coke at temperatures of 750 DEG , 800 DEG , 850 DEG , and 900 DEG  C. After each stage, the unsaturated hydrocarbons are separated by cooling.  The residual gas, which consists of methane and hydrogen, is led together with an excess of steam over a catalyst consisting of aluminium oxide and nickel, the methane being converted to hydrogen with partial formation of carbon monoxide and dioxide.