摘要:
A process is set forth for the cryogenic distillation of an air feed to produce an ultra-high purity oxygen product. A first oxygen-containing but heavy contaminants-lean (free) stream is removed from the main distillation column system and subsequently stripped in an auxiliary distillation column. A second oxygen-containing but light contaminants-lean (free) gaseous stream is also removed from the main distillation column system and subsequently fed to the bottom section of the auxiliary distillation column in order to provide heat duty/reboil to the bottom of the auxiliary distillation column. The ultra-high purity oxygen product (ie total contaminant concentration less than 10.0 vppm, preferably less than 1.0 vppm) is withdrawn from an intermediate section of the auxiliary distillation column.
摘要:
A process for separating a feed gas mixture into a more strongly adsorbable component and a less strongly adsorbable component in a plurality of adsorbent beds containing an adsorbent selective for the more strongly adsorbable component with two cocurrent depressurizations, first to provide product and then to provide a purge gas, and using a combination of less strongly adsorbable component and feed gas mixture to repressurize the adsorbent bed. Oxygen product can be recovered from air at high recovery using the process.
摘要:
The present invention relates to the heat exchanger system in a process for the cryogenic distillation of air. In particular, the present invention is an improvement to the heat exchanger system to increase the operational efficiency of the process.
摘要:
The present invention is a liquid nitrogen reflux means improvement capable of allowing the operation of conventional dual and triple reboiler air separation cycles at elevated pressures. The improvement comprises: (a) heat exchanging a portion of the liquid oxygen bottoms of the second column against a nitrogen vapor stream removed from the higher or lower pressure columns or derived from the gaseous nitrogen product, wherein prior to such heat exchange the pressure of the liquid oxygen bottoms portion or the nitrogen vapor stream or both the pressure of the liquid oxygen bottoms portion and the nitrogen vapor stream is adjusted by an effective amount so that an appropriate temperature difference exists between the liquid oxygen bottoms and the nitrogen vapor stream so that upon heat exchange the nitrogen vapor is totally condensed and the liquid oxygen bottoms portion is at least partially vaporized; (b) utilizing the condensed nitrogen as reflux in at least one of the two distillation columns; and (c) warming the vaporized oxygen to recover refrigeration.
摘要:
The present invention relates to an improvement for the production of argon from cryogenic air separation processes. In particular, the improvement comprises using a first heat pump cycle to transfer refrigeration from the bottom of the low pressure column to the top of the crude argon column and a second heat pump cycle to transfer refrigeration from the bottom of the low pressure column to the top of the low pressure column.
摘要:
This invention relates to a cryogenic process for the separation of air utilizing an integrated multi-column distillation system wherein an ultra high purity nitrogen product is generated. In the cryogenic distillation separation of air, air is initially compressed, pretreated and cooled for separation into its components. Ultra high purity, e.g., nitrogen typically having less than 0.1 ppm impurities is generated in a multi-column distillation system comprising a first column and an ultra high purity nitrogen column with enhanced nitrogen product recovery by withdrawing a gaseous nitrogen fraction from a first column and charging the fraction as a feed to the ultra high purity nitrogen column, withdrawing a nitrogen stream which is rich in volatile contaminants from the top of the ultra high purity nitrogen column and recovering a nitrogen product at a point below the removal point of the nitrogen rich stream containing volatile components. Removal of volatile components in the distillation process is effected by partially condensing a nitrogen vapor stream from either the first column or the ultra high purity column and removing at least one of the uncondensed portions of the nitrogen rich stream containing volatile components as a purge stream.
摘要:
This invention relates to a cryogenic process for the separation of air utilizing an integrated multi-column distillation system wherein a nitrogen rich, oxygen rich and argon rich product are generated. In the cryogenic distillation separation of air, air is initially compressed, pretreated and cooled for separation into its components. Moderate pressure, e.g., 25-80 psia nitrogen is generated with enhanced nitrogen product purity and greater recovery of both nitrogen and argon by effecting a high boil-up rate in the bottom of the lower pressure column, thereby creating a reduced liquid flow/vapor flow ratio (L/V) and utilizing a higher than customary nitrogen reflux to the top of the lower pressure column, where the concentration of oxygen in nitrogen is less than about 10 ppm by volume or the nitrogen purity is at least about 99.5% by volume. Refrigeration to drive the system is obtained by recovering the energy from the waste nitrogen stream and oxygen vapor from the lower pressure column. A second method for obtaining refrigeration is to withdraw oxygen as a bottoms liquid from the lower pressure column, expanding that liquid to a lower pressure and using it to condense the nitrogen vapor generated in a higher pressure column which has been expanded in a turbo-expander to provide the refrigeration.
摘要:
A process for selectively producing ortho-alkylated aromatic amines in high selectivity relative to N-alkylated aromatic amines. The process comprises reacting an aromatic amine, having at least one hydrogen atom in a position ortho to the amine functionality, and an olefin under conditions sufficient to effect an alkylation reaction, in the presence of a zeolite catalyst which has been thermally pretreated by heating the catalyst to a temperature greater than about 500.degree. C. for a period ranging from 0.5 to about 10 hours while sweeping an inert gas over the heated catalyst to remove water and ammonia formed during the thermal treatment, and subsequently recovering the alkylated aromatic amine.
摘要:
The present invention is an improvement to a method of producing crude argon directly from the cold box of a cryogenic air separation unit. The improvement is the production of crude argon containing greatly decreased concentrations of oxygen, i.e.
摘要:
A process for making high purity argon is disclosed in which crude argon containing less than about 0.8 mol % oxygen is recovered from air in a cryogenic distillation system, the crude argon is purified by removing oxygen in a getter system, and other impurities are removed by cryogenic distillation to yield a high purity argon product. The crude argon purification system is heat integrated with the main cryogenic air separation system. High purity argon can be produced at argon recoveries greater than 90% by utilizing structured packing in at least a portion of the argon sidearm column.