摘要:
According to this process, in the case of a reduction in the production rate, the maximum pressure PM of the cycle is lowered and the ratio of this maximum pressure to the minimum pressure Pm of the cycle is reduced, in particular by altering the durations of compression and decompression stages. The process is applicable to the production of oxygen at variable rate.
摘要:
A process for concentrating ozone, which includes switching a plurality of adsorption columns each packed with an adsorbent capable of preferentially adsorbing ozone thereon sequentially to an adsorption step where the adsorbent is maintained at a low temperature to adsorb ozone thereon; a desorption step where the adsorbent is heated to desorb ozone therefrom, and a scavenger gas is introduced in a substantially fixed amount into the adsorption column to discharge the thus desorbed ozone being carried on the scavenger gas; and a cooling step where the adsorbent having completed the desorption step is cooled to the same low temperature level as in the adsorption step. Heating of the adsorbent in the desorption step is carried out depending on the time elapsed after desorption is started or on the ozone concentration of the gas discharged from the adsorption column performing the desorption step. A gas having a predetermined pressure is employed as the scavenger gas in the desorption step. The adsorption step is divided into two steps: a pre-adsorption sub-step and a main adsorption sub-step. A low-temperature oxygen is employed as a cooling source in the cooling step and then supplied as a raw material of ozone to the ozonizer.
摘要:
An adsorption process in which high and low pressure feed streams are introduced into a plurality of beds to produce product streams by adsorbing one or more preferentially adsorbed components within the beds. Each bed is subjected to a low pressure feed stage to produce a low pressure product stream followed by a high or higher pressure feeding stages to produce one or more high pressure product streams. Thereafter the beds are regenerated through depressurization and purge stages. The cycle is conducted out of phase so that one of the beds is producing the high pressure product stream while another bed is producing a low pressure product stream.
摘要:
A method of adsorption separation of gases of the kind which regenerates the adsorbant by pressure viariation and used two adsorbers, wherein the recompression stage includes at least one recompression stage using the oxygen produced, and a final recompression stage up to the high point of the cycle pressure using air intake without draw-off; and wherein the pressure high-point of the cycle is selected between 1.2 and 2 .times.10.sup.5 Pa and the pressure low-point is selected between 0.3-0.7.times.10.sup.5 Pa, at least the final part of the desorption stage being carried out by pumping. The method is essentially relevant to the production of oxygen.
摘要:
Highly purified gaseous hydrogen and liquid carbon dioxide are produced from a steam reformer/shift converter by passing the effluent from the latter through a multibed hydrogen PSA unit followed by an uncoupled carbon dioxide PSA unit. The carbon dioxide PSA unit produces a hydrogen-rich stream which is recycled to the feed to the steam reformer, a carbon dioxide-rich recycle stream which is recycled to the carbon dioxide PSA unit feed and a carbon dioxide-rich product stream which is introduced under pressure to a liquifier. A waste stream from the liquifier is recycled to the carbon dioxide PSA unit feed. A portion of the carbon dioxide-rich product stream is withdrawn from the compressor at a stage such that its pressure is higher than that of the carbon dioxide PSA unit and returned thereto as a cocurrent purge preceding bed regeneration to obtain product.
摘要:
A process for producing a high purity oxygen from air by PSA which comprises connecting a first adsorption unit packed with carbon molecular sieve and a second adsorption unit packed with zeolite molecular sieve in series, conducting PSA operation separately in each of the units during the same operation cycle time, accumulating the desorption gas from the first adsorption unit in a receiver and then introducing the resulting desorption gas to the second unit as a raw material gas and to the first unit as a rinse gas.
摘要:
An adsorption installation is employed for the purification of several crude gas streams. The individual crude gas streams are conducted separately from one another through the adsorbers in cyclic alternation. Preferably, an adsorber is regenerated only after all crude gas streams have been passed through the adsorber. The number of adsorbers utilized can be kept lower than in the separate purification of each individual crude gas stream.
摘要:
The invention relates to a process and apparatus for separating mixed gas by adsorption in which adsorption and desorption steps are repeatedly carried out in a plurality of adsorption towers in staggered timings.The invention is characterized in that upon commencement of the desorption step, mixed gas having a low adsorbate constituent gas concentration which is delivered in the initial part of a pressure-reducing period (a primary pressure-reducing period) in an adsorption tower which has completed adsorption, is fed into an adsorption tower which has finished pressure-reduction to scavenge and desorb the adsorbate constituent gas adsorbed by an adsorbent, whereby enhancement of a yield of an unadsorbate gas can be achieved as compared to scavenging desorption making use of a part of an unadsorbate gas delivered during an adsorption step.
摘要:
A process for providing a feed gas for a chemical reaction and for separating a gaseous reaction product from the gaseous mixture obtained by the reaction, wherein the feed gas is obtained by the fractionation of a crude gas mixture containing this feed gas proper, as well as a carrier gas or carrier gas mixture, and is reacted only incompletely in the reaction, and wherein the unreacted proportion is to be recycled into the reaction, the improvement wherein the fractionation of the crude gas mixture and the separation of the gaseous reaction product are conducted in a single adsorption plant operating by the pressure swing method and containing cyclically reversible adsorbers.
摘要:
A method and apparatus for the separation of gases by preferential adsorption of at least one of the gases in which at least three adsorption zones are used, at least two of which are arranged in series to form the separation zone while at least one other is being regenerated for re-use in the separation zone, and in which periodically a fresh zone is added to the end of the separation section from which the product gas is recovered and the zone forming the first zone of the separation section is removed for regeneration whereby each zone is successively incorporated into the separation section and subsequently removed from it and regenerated ready for reincorporation into the separation section. Improved utilization of adsorbent and reduced loss of product gas for regeneration purposes is thereby achieved without loss of product purity.