Patent GB-800888-A (GB)
Title: Process for the simultaneous production of acetylene and a mixture of nitrogen and hydrogen
Inventor: SELLERS FREDERICK B
IPC: F25J3/02
Filed: 1956-06-11
Abstract: <PICT:0800888/III/1> Acetylene and a mixture of nitrogen and hydrogen are produced by liquefying and rectifying air to give nitrogen and a mixture of oxygen and argon, reacting a gaseous or vaporous hydrocarbon with the latter oxygen mixture in the ratio of 0.45 to 0.65 mol. of oxygen per carbon atom in the hydrocarbon for 0.001 to 0.1 second at 2500-3500 DEG  F. and near atmospheric pressure to give acetylene with carbon monoxide, hydrogen, argon and methane, removing acetylene by solvent absorption, converting carbon monoxide to carbon dioxide with production of more hydrogen by reaction with steam, removing carbon dioxide and water, cooling to condense argon, removing residual carbon monoxide and methane by passing through liquid nitrogen and concomitantly vaporizing nitrogen to give a mixture of 3 parts hydrogen to 1 part nitrogen by volume. The oxygen and hydrocarbon are preheated before the partial combustion process and this step may be carried out by means of gases produced by burning a hydrocarbon to give essentially carbon monoxide and hydrogen by reaction with 0.55 to 0.75 mol. of oxygen per atom of carbon in the hydrocarbon at 2200-3200 DEG  F. and atmospheric to 1000 p.s.i.g. pressure for 1 to 5 seconds, the hot gas so produced being added to the gases from the partial combustion step after acetylene has been removed.  The oxygen in this step may be in the form of air or oxygen from the rectification of air.  Air is liquefied and rectified in the air-rectification plant 6.  The gas generator 10 is used to produce hot flue gases by burning a fuel; preferably a hydrocarbon is burned with oxygen from line 38 or air from compressor 39 to give principally carbon monoxide and hydrogen. Oxygen from line 7 and the hydrocarbon such as a natural gas from line 11 are preheated by the flue gases from the gas generator 10 in the heat exchanger 8 and reacted in the acetylene generator 9. The product gases are immediately quenched by introduction of water through lines 12.  After separation of water in the separator 14 the gases pass to the acetylene absorption stage 15 where acetylene is dissolved in a liquid solvent such as dimethyl formamide.  The remaining gases, principally carbon monoxide and hydrogen, with some methane and argon are compressed and warmed and may be mixed with gases from the generator 10 supplied through line 37.  These gases with steam from line 18 are supplied to the shift converter 19, where carbon monoxide reacts with steam in the presence of an iron catalyst to give carbon dioxide and hydrogen. Carbon dioxide and water are removed in the purification unit 22, the former by absorption in an aqueous solution of monoethanolamine followed by a caustic wash, the latter by condensing by cooling to 40 DEG  F. and desiccation with bauxite, alumina or silica gel.  The remaining gas is principally hydrogen with small amounts of carbon monoxide, methane, argon, water vapour and carbon dioxide.  This gas is passed via the heat exchanger 24, where it is cooled, and line 23B, to the wash tower 26 down which flows liquid nitrogen from line 27.  Here all impurities are removed and the hydrogen mixed with some nitrogen leaves via line 28A through heat exchanger 24 and line 28B. Further nitrogen is supplied by line 29 if necessary.ALSO:<PICT:0800888/IV (b)/1> Acetylene and a mixture of nitrogen and hydrogen are produced by liquefying and rectifying air to give nitrogen and a mixture of oxygen and argon, reacting a gaseous or vaporous hydrocarbon with the latter oxygen mixture in the ratio of 0.45 to 0.65 mol. of oxygen per carbon atom in the hydrocarbon for 0.001 to 0.1 second at 2500-3500 DEG  F. and near atmospheric pressure to give acetylene with carbon monoxide, hydrogen, argon and methane, removing acetylene by solvent absorption, converting carbon monoxide to carbon dioxide with production of more hydrogen by reaction with steam, removing carbon dioxide and water, cooling to condense argon, removing residual carbon monoxide and methane by passing through liquid nitrogen and concomitantly vaporizing nitrogen to give a mixture of 3 parts hydrogen to 1 part nitrogen by volume. The oxygen and hydrocarbon are preheated before the partial combustion process and this step may be carried out by means of gases produced by burning a hydrocarbon to give essentially carbon monoxide and hydrogen by reaction with 0.55 to 0.75 mol. of oxygen per atom of carbon in the hydrocarbon at 2200-3200 DEG  F. and atmospheric to 1000 p.s.i.g. pressure for 1 to 5 seconds, the hot gas so produced being added to the gases from the partial combustion step after acetylene has been removed.  The oxygen in this step may be in the form of air or oxygen from the rectification of air.  Air is liquefied and rectified in the air-rectification plant 6.  The gas generator 10 is used to produce hot flue gases by burning a fuel; preferably a hydrocarbon is burned with oxygen from line 38 or air from compressor 39 to give principally carbon monoxide and hydrogen.  Oxygen from line 7 and the hydrocarbon such as a natural gas from line 11 are preheated by the flue gases from the gas generator 10 in the heat exchanger 8 and reacted in the acetylene generator 9.  The product gases are immediately quenched by introduction of water through lines 12. After separation of water in the separator 14 the gases pass to the acetylene absorption stage 15 where acetylene is dissolved in a liquid solvent such as dimethyl formamide.  The remaining gases principally carbon monoxide and hydrogen with some methane and argon are compressed and warmed and may be mixed with gases from the generator 10 supplied through line 37.  These gases with steam from line 18 are supplied to the shift converter 19, where carbon monoxide reacts with steam in the presence of an iron catalyst to give carbon dioxide and hydrogen. Carbon dioxide and water are removed in the purification unit 22, the former by absorption in an aqueous solution of monoethanolamine followed by a caustic wash, the latter by condensing by cooling to 40 DEG  F. and desiccation with bauxite, alumina or silica gel.  The remaining gas is principally hydrogen with small amounts of carbon monoxide, methane, argon water vapour and carbon dioxide.  This gas is passed via the heat exchanger 24, where it is cooled and line 23B, to the wash tower 26 down which flows liquid nitrogen from line 27.  Here all impurities are removed and the hydrogen mixed with some nitrogen leaves via line 28A through heat exchanger 24 and line 28B.  Further nitrogen is supplied by line 29 if necessary.