摘要:
Cryogenic apparatus comprising a liquefier (11) and a dual column system distillation column system (81) selectively operates in a first mode during which only liquid nitrogen (130) is produced and a second mode during which liquid nitrogen (130) and liquid oxygen (106) are produced. By adjusting the time of operation in each mode, any ratio of liquid nitrogen (130) to liquid oxygen (106) greater than the ratio achieved during the second mode of operation can be achieved. In the first mode of operation, a condenser (88) is used to condense the lower pressure column gaseous nitrogen into lower pressure column nitrogen condensate (122) against at least a portion (146) of the crude oxygen liquid (92) from the higher pressure column (82), at least a portion (108) of the oxygen-enriched liquid (104) from the lower pressure column (86), at least a portion (138) of the liquefied air (134), or mixtures thereof. In the second mode of operation, said condenser (88) is not used; instead, all of the crude oxygen liquid (92) is introduced into the lower pressure column (86), which produces a liquid oxygen product (106) and a low pressure overhead waste stream (152) containing nitrogen.
摘要:
A system for processing nitrogen-containing effluent from an industrial process wherein the effluent is cooled and liquid nitrogen is added directly to the cooled effluent. The direct contact and heat exchange produces gaseous nitrogen and liquid organics which are both used to cool the effluent and are subsequently recovered.
摘要:
Air is compressed in compressors 2, 6 and 8, cooled in a main heat exchanger 10, and separated into oxygen and nitrogen products in a double rectification column 20 comprising a higher pressure rectification column 22 and a lower pressure rectification column 24. A liquid oxygen product is withdrawn from the column 24 via a conduit 50. A liquid nitrogen product is also formed. An argon-enriched oxygen vapour stream is withdrawn from the column 24 through an outlet 54 and has argon separated from it in a column 42. In order to help meet the requirements of the column 20 for reflux, a nitrogen vapour stream is withdrawn from the top of the column 24, is warmed by passage through the heat exchanger 10, is recompressed in compressor 66, and is liquefied by passage back through the heat exchanger from its warm end 12 to its cold end 14 and passage through valve 70. A high liquid make and a high argon recovery can both be achieved.
摘要:
A system for producing liquid nitrogen (239,447) from a nitrogen-containing hydrocarbon stream (200,301) wherein excess refrigeration existing in a nitrogen rejection unit (Fig.1) or in an integrated nitrogen rejection unit-helium rejection unit system (Fig.2) is utilized to effectively generate a liquid nitrogen product stream.
摘要:
A method and system for supplying compressed air (70) to a process plant using a combustor-turbine unit (10) directly coupled to a bull gear meshing with pinions (44,56) on which are mounted gas compression stages (46,50,58,64) and expansion stages. Some stages compress a stream of air supplied to the combustor-turbine unit for combustion and to the process plant. Other stages expand or compress other gas streams directed to the combustor-turbine unit or to external applications. Direct energy transfers and intercooling and aftercooling after compression stages enhance the efficiency of the system.
摘要:
A method for producing carbon dioxide and nitrogen from combustion exhaust gas containing less than about 10% oxygen by weight comprises the steps of (a) treating the exhaust gas to remove particulate matter, (b) compressing the exhaust gas to a pressure in the range from about 25 psia to about 200 psia, (c) purifying the exhaust gas to remove trace contaminants, (d) separating the exhaust gas to produce a carbon dioxide rich fraction and a nitrogen rich fraction, (e) liquefying the carbon dioxide rich fraction and distilling off volatile contaminants to produce pure carbon dioxide, (f) purifying the nitrogen rich fraction to remove contaminants, and (g) cryogenically fractionally distilling the nitrogen rich fraction to produce pure nitrogen and preferably arc argon-enriched fraction which is then separated to produce argon. The combustion exhaust gas may be obtained from an ammonia plant reformer furnace and the nitrogen produced may be employed to synthesise ammonia. The carbon dioxide may be reacted with the ammonia to form urea.
摘要:
The present invention provides a method for concentrating nitrogen isotope comprising a step for obtaining a final product nitrogen, in which the stable nitrogen isotope, 15 N, has been concentrated, by low-temperature distillation of raw material nitrogen containing trace amounts of oxygen and argon with a plurality of distillation columns composed in a cascade arrangement, wherein together with discharging an argon-oxygen mixture from the bottom of the final column and extracting a 15 N-concentrated nitrogen fluid from a lower intermediate point of the final column, the flow rate of the argon-oxygen mixture discharged from the bottom of the final column is controlled based on the reading of a thermometer installed below the point where the final product 15 N-concentrated nitrogen is extracted, thereby enabling the final product nitrogen to be stably obtained.