According to one or more embodiments, a method for forming light olefins may comprise introducing a hydrocarbon feed stream into a reactor, reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product, separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

According to one or more embodiments, a method for forming light olefins may comprise introducing a hydrocarbon feed stream into a reactor, reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product, separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

According to one or more embodiments, a method for forming light olefins may comprise introducing a hydrocarbon feed stream into a reactor, reacting the hydrocarbon feed stream with a dehydrogenation catalyst in the reactor to form a high temperature dehydrogenated product, separating at least a portion of the dehydrogenation catalyst from the high temperature dehydrogenated product in a primary separation device, combining the high temperature dehydrogenation product with a quench stream to cool the high temperature dehydrogenation product and form an intermediate temperature dehydrogenation product, and cooling the intermediate temperature dehydrogenation product to form a cooled dehydrogenation product.

The composite according to the present invention comprises: a mesoporous inorganic support having vacancy defects; and metal alloy nanoparticles dispersed in and bound to the mesoporous inorganic support and containing a precious metal element and an earth rare element. The composite according to the present invention has a very high specific surface area since the alloy is dispersed and present in the form of ultrafine nanoparticles in the porous support, and thus can show remarkably improved activity when used as a material for a chemical reaction, including a catalyst.

The invention relates to a process, unit and reaction system of low-carbon alkane dehydrogenation, which comprises the following steps: C3-C5 low-carbon alkane feed gas, together with CO and/or CO.sub.2 process gas, get into reactor after being preheated to 200-500° C., contact with a Cr—Ce—Cl/Al.sub.2O.sub.3 dehydrogenation catalyst, a Cu—Ce—Ca—Cl/Al.sub.2O.sub.3 thermal generating agent and thermal storage/support inert alumina balls, and convert to dehydrogenation products for 5-30 minutes under the conditions: temperature, 500-700° C., pressure, 10-100 kPa and weight hourly space velocity (WHSV), 0.1-5 hours.sup.−1. The products formed enter the downstream separation unit for separating out the low-carbon alkenes. The periodic regeneration process of the catalyst bed includes steam purging, hot air regenerating, bed heating, evacuating and reducing at 560 to 730° C. and 0.01 to 1 MPa. Each cycle needs about 10-70 minutes. With such dehydrogenation process, the reaction heat balance is moderated, and temperature gradient and reaction severity in the catalyst bed are reduced. As a consequence, the catalytic conversion, product selectivity, operation cycle and service life are improved. The system energy consumption is reduced.

The invention discloses a catalyst for propane dehydrogenation to propylene and a preparation method and application thereof. The catalyst comprises a support, an active component and promoters supported on the carrier. Among them, the carrier is alumina ball, the active component is platinum group metal, the promoters include three kinds: rare earth elements (Y, La, Ce, Pr, Nd), tin, and alkali metal elements (Li, Na, K). When the catalyst is used for propane dehydrogenation to propylene, higher propane conversion and propylene selectivity are obtained.

According to one or more embodiments presently disclosed, a method for processing a chemical stream may include contacting a feed stream with a catalyst in a reactor portion of a reactor system that includes a reactor portion and a catalyst processing portion. Contacting the feed stream with the catalyst may cause a reaction forming an effluent. The method may include separating the effluent stream from the catalyst, passing the catalyst to the catalyst processing portion, and processing the catalyst in the catalyst processing portion. Processing the catalyst may include passing the catalyst to a combustor, combusting a supplemental fuel stream in the combustor to heat the catalyst, and treating the heated catalyst with an oxygen-containing gas. The supplemental fuel stream may include at least 1 mol % of one or more hydrocarbons, and a weight ratio of catalyst to hydrocarbons in the combustor may be at least 300:1.

Provided is a method for using selective non-catalytic reduction to reduce nitrogen dioxide in exhaust gas generated during an olefin production process. Nitrogen dioxide generated in a catalyst regeneration step of a continuous PDH process can be efficiently removed by the method of the present disclosure. Ultimately, the generation of visible fumes can be prevented through the removal of nitrogen dioxide.

Provided is a method for using selective non-catalytic reduction to reduce nitrogen dioxide in exhaust gas generated during an olefin production process. Nitrogen dioxide generated in a catalyst regeneration step of a continuous PDH process can be efficiently removed by the method of the present disclosure. Ultimately, the generation of visible fumes can be prevented through the removal of nitrogen dioxide.

Disclosed are methods of dehydrogenating a light alkane gas (and/or light alkene gas), which include adding hydrogen (H.sub.2) to the light alkane gas (and/or light alkene gas) in the presence of a catalyst composition containing zirconium oxide. Also disclosed are catalyst compositions containing zirconium oxide and methods of preparation thereof, where the catalyst compositions are useful in methods of dehydrogenating light alkane gas.