| 摘要 |
The invention relates to a process for preparing ammonia from hydrogen and nitrogen, the highly pure hydrogen used being separated out from the purge gases and/or spent gases resulting from the methanol producing process, from the catalytic reforming, dealkylation, hydrotreatments, hydrodesulphuration, pyrolysis, thermal catalytic cracking; the gases contain 50.5...94% H2, 6...21.6% CH4, 0...17% hydrocarbons having 2...4 carbon atoms, 0...5% CO, 0...4.5% CO2, 0...0.8% N2, 0...0.03% dimethylether, 0...0.51% CH3-OH, 0...0.06% H2O and have a pressure of 25...145 at. The hydrogen separated this way has a concentration of at least 99.99%, a temperature of 35...40°C and a pressure of 22...140 at and is mixed in a volumetric ratio of 3:1 with the nitrogen having a purity of at least 99.99%, compressed at a pressure of 22...140 at and cooled to 35...40°C. The mixture so obtained is introduced in a pre-catalyzing installation and then passes to the ammonia synthesis phase. The prepared ammonia is then stored as liquid ammonia, and the gases resulting from its expansion, containing nitrogen, hydrogen and ammonia, are fed either into a washing plant wherefrom ammonia water results in a concentration of 25%, or to an ammonia-to-nitric acid absorption plant wherefrom ammonium nitrate results. The resulting nitrogen - hydrogen mixture is delivered as fuel. The heat eliminated during the synthesis process is recovered, thereby steam of 1.5...110 at being produced.
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