Patent GB-727156-A (GB)
Title: Improvements relating to the treatment of gas works effluent liquors
IPC: C10K1/00
Filed: 1952-04-30
Abstract: In a process for treating the ammoniacal liquors obtained in a gas works, the retort house liquor and the liquor from the hot sections of the condensers and the gas detarrers are stripped of free ammonia and dephenolated while the other liquors such as the liquors from the washing processes and cooler sections of the condensers are distilled to obtain concentrated ammonia liquor, in each case an effluent liquor being obtained suitable for discharge into a sewer.  The retort house liquor may be dephenolated by extraction with butyl acetate or methyl isobutyl ketone and the phenols, which are mainly polyhydric phenols, after separation from the solvent may be burnt in a furnace.  The washing liquor may also be dephenolated, for example by extraction with benzene, in which case the effluent liquors may be discharged into a river if the toxicity of the river is not important.  The phenols, which in this case are mainly monohydric phenols, may be separated from the benzene solution by steam distillation or extraction with caustic soda.  The effluent liquor obtained in distilling the washing liquor may also be partly used in gas washing plant, the remainder being discharged to a sewer or river or concentrated and the concentrate treated with sulphuric or nitric acid or destroyed in a coke-burning furnace.  The effluent liquor resulting from the treatment of the retort house liquor if it is not desired to or it is impossible to discharge it into a sewer or a river may be concentrated to obtain ammonium chloride and the mother liquor treated with acid or destroyed in a coke-burning furnace.ALSO:In a process for treating the ammoniacal liquors obtained in a p  gas works, the retort house liquor and the liquor from the hot sections of the condensers and the gas detarrers are stripped of free ammonia and dephenolated while the other liquors such as the liquors from the washing processes and cooler sections of the condensers are distilled to obtained concentrated ammonia liquor, in each case an effluent liquor being obtained suitable for discharge into a sewer.  The retort house liquor may be dephenolated by extraction with butyl acetate or methyl isobutyl ketone and the phenols, which are mainly polyhydric phenols, after separation from the solvent may be burnt in a furnace.  The washing liquor may also be dephenolated, for example by extraction with benzene, in which case the effluent liquors may be discharged into a river if the toxicity of the river is not important.  The phenols, which in this case are mainly monohydric phenols, may be separated from the benzene solution by steam distillation or extraction with caustic soda.  The effluent liquor obtained in distilling the washing liquor may also be partly used in gas washing plant, the remainder being discharged to a sewer or river or concentrated and the concentrate treated with sulphuric or nitric acid or destroyed in a coke-burning furnace.  The effluent liquor resulting from the treatment of the retort house liquor if it is not desired to or it is impossible to discharge it into a sewer or a river may be concentrated to obtain ammonium chloride and the mother liquor treated with acid or destroyed in a coke-burning furnace.ALSO:In a process for treating the ammoniacal liquors obtained in gas works, the retort house liquor and the liquor from the hot sections of the condensers and the gas detarrers are stripped of free ammonia and dephenolated while the other liquors such as the liquors from the washing processes and cooler sections of the condensers are distilled to obtain concentrated ammonia liquor, in each case an effluent liquor being obtained suitable for discharge into a sewer.  The retort house liquor may be dephenolated by extraction with butyl acetate or methyl isobutyl ketone and the phenols, which are mainly polyhydric phenols, after separation from the solvent may be burnt in a furnace.  The washing liquor may also be dephenolated, for example by extraction with benzene, in which case the effluent liquors may be discharged into a river if the toxicity of the river is not important.  The phenols, which in this case are mainly monohydric phenols, may be separated from the benzene solution by steam distillation or extraction with caustic soda.  The effluent obtained in distilling the washing liquor may also be partly used in gas washing plant, the remainder being discharged to a sewer or river or concentrated and the concentrate treated with sulphuric or nitric acid or destroyed in a coke-burning furnace.  The effluent liquor resulting from the treatment of the retort house liquor if it is not desired to or it is impossible to discharge it into a sewer or a river may be concentrated to obtain ammonium chloride and the mother liquor treated with acid or destroyed in a coke-burning furnace.