Disclosed are embodiments of a method of regenerating a desiccant in an off-line treater of a polyolefin production process. The method may include a heating phase followed by a cooling phase. The heating phase may involve use of a regenerating gas made from heating a treated a recycle stream of the polyolefin production process to regenerate desiccant in an off-line treater. The cooling phase may involve thermosyphoning the regenerating gas, nitrogen, an olefin-free diluent, or combinations thereof in a closed-convection loop of the off-line treater.

An adsorption process for xenon recovery from a cryogenic liquid or gas stream is described wherein a bed of adsorbent is contacted with the aforementioned xenon containing liquid or gas stream and adsorbs the xenon selectively from this fluid stream. The adsorption bed is operated to at least near full breakthrough with xenon to enable a deep rejection of other stream components, prior to regeneration using the temperature swing method. Operating the adsorption bed to near full breakthrough with xenon, prior to regeneration, enables production of a high purity product from the adsorption bed and further enables oxygen to be used safely as a purge gas, even in cases where hydrocarbons are co-present in the feed stream.

This present disclosure relates to processes for removing contaminants from hydrocarbon streams, e.g. removing chlorides, CO.sub.2, COS, H.sub.2S, AsH.sub.3, methanol, mercaptans and other S- or O-containing organic compounds from olefins, paraffins, aromatics, naphthenes and other hydrocarbon streams. The process involves contacting the stream with an adsorbent which comprises a zeolite, an alumina component and a metal component e.g. sodium, in an amount at least 30% of the zeolite's ion exchange capacity.

A method for continuously treating a regeneration gas stream used to regenerate a molecular sieve adsorption vessel is disclosed. The regeneration gas stream is cooled in a cooler to a temperature suitable to condense liquids therein. A separator removes liquids condensed in the regeneration gas stream. The regeneration gas stream is compressed in a compressor. The regeneration gas stream is flowed through the cooler, the separator, and the compressor when the compressor is operational. The regeneration gas stream is flowed through the second cooler and the second separator but not the compressor when the compressor is not operational, thereby enabling continuous treatment of the regeneration gas stream.

The present disclosure describes the use of a specific adsorbent material in a rapid cycle swing adsorption to perform dehydration of a gaseous feed stream. The adsorbent material includes a zeolite 3A that is utilized in the dehydration process to enhance recovery of hydrocarbons.

A method for extending useful life of a sorbent for purifying a gas by sorption of an impurity is provided. The method generating a electrical discharge within the gas to obtain a spectral emission representative of a concentration of the impurity. The method also includes monitoring the concentration of the impurity according to the spectral emission. The method also includes lowering the concentration of the impurity by conversion of at least a portion of the impurity into a secondary impurity having a greater affinity to the sorbent than the impurity. The method also includes comparing the concentration of the impurity to a polluting concentration and managing the sorption of the gas onto the sorbent according to the comparison.

A process is provided to remove impurities including water, mercaptans, carbonyl sulfide and hydrogen sulfide from hydrocarbon streams containing from 100 to 900 ppm light olefins. In the process, a compound bed containing multiple layers of molecular sieves is used to remove the specific impurities. In situations when the regeneration gas may contain sulfur compounds, a sulfur guard bed may be used to treat the regeneration gas prior to regenerating the compound adsorbent bed.

Disclosed are embodiments of a method of regenerating a desiccant in an off-line treater of a polyolefin production process. The method may include a heating phase followed by a cooling phase. The heating phase may involve use of a regenerating gas made from heating a treated a recycle stream of the polyolefin production process to regenerate desiccant in an off-line treater. The cooling phase may involve thermosyphoning the regenerating gas, nitrogen, an olefin-free diluent, or combinations thereof in a closed-convection loop of the off-line treater.

An active catalyst for ammonia synthesis is integrated with a specialty sorbent in a composition or composite, such that the catalyst portion and the sorbent portion are in direct intimate contact, which overcomes the thermodynamic limits for conversion. The sorbent may comprise a metal halide absorbent, zeolite adsorbent, other material absorbents or adsorbents, to capture ammonia as it is produced in intimate or near molecular contact with the catalyst, wherein the composition/composite may be provided in the form of a granular or pellet structure. By removing ammonia essentially as it forms, the forward reaction for producing ammonia can continue nearly unabated such that high net conversion can be achieved in a single pass or cumulative within segmented reactors as operated in series.

The invention provides a process of purifying a fluid useful in a manufacturing process, particularly in the manufacture of silicon wafers, by removing one or more impurities; and apparatus for use in the process.