A method and an apparatus for preparing an oligomer, the method including supplying a feed stream including a monomer to a reactor to perform an oligomerization reaction, recovering unreacted monomer, and dissolving the recovered unreacted monomer in a solvent in a monomer dissolution device and supplying a discharge stream from the monomer dissolution device to the reactor. The method and the apparatus provide reduced investment costs and improved economic feasibility as there is no need to use a refrigerant at a very low temperature or install a separate compressor to recover and reuse the unreacted monomer in an oligomer production process.

A process for producing olefins comprising introducing butane feed (n-butane, i-butane) and hydrogen to hydrogenolysis reactor comprising hydrogenolysis catalyst to produce a hydrogenolysis product stream (hydrogen, methane, ethane, propane, i-butane, optionally n-butane, optionally C.sub.5+ hydrocarbons); and feeding the hydrogenolysis product stream and hydrogen to hydrocracking reactor comprising a hydrocracking catalyst to produce hydrocracking product stream (hydrogen, methane, ethane, propane, i-butane, optionally n-butane), wherein the amount of i-butane in the hydrocracking product stream is less than in the hydrogenolysis product stream, and wherein the amount of ethane in the hydrocracking product stream is greater than in the hydrogenolysis product stream. The hydrocracking product stream is separated into first hydrogen stream, first methane stream, first C.sub.2+ gas stream (ethane, propane), first C.sub.4s stream (i-butane, optionally n-butane), optionally C.sub.5+ stream; and the first C.sub.2+ gas stream is fed to gas steam cracker to produce a steam cracker product stream comprising olefins (ethylene, propylene).

The invention relates to a process for the production of ethylene by oxidative dehydrogenation of ethane, comprising: a) subjecting a stream comprising ethane to oxidative dehydrogenation conditions, resulting in a stream comprising ethylene, unconverted ethane and light components; b) subjecting ethylene, unconverted ethane and light components from the stream resulting from step a) to distillation, resulting in a stream comprising ethylene and light components and a stream comprising unconverted ethane; c) optionally recycling unconverted ethane from the stream comprising unconverted ethane resulting from step b) to step a); and d) subjecting ethylene and light components from the stream comprising ethylene and light components resulting from step b) to distillation at a top column pressure which is higher than the top column pressure in step b), resulting in a stream comprising light components and a stream comprising ethylene.

In a propane dehydrogenation (PDH) process, the purpose of the deethanizer and chilling train systems is to separate the cracked gas into a methane-rich tail gas product, a C2, and a C3 process stream. By the use of staged cooling, process-to-process inter-change against propane feed to the reactor and use of high efficiency heat exchangers and distributed distillation techniques, refrigeration power requirements are reduced and a simple and reliable design is provided by the process described herein.

System and method for producing 1-butene are disclosed. The method includes dehydrogenating butane to form a mixture comprising butene isomers. 1-butene is separated from the mixture using a system that includes a membrane. The system also includes an isomerizing unit for isomerizing cis-2-butene and trans-2-butene to form additional 1-butene.

The present disclosure provides a method of separating α-olefin by a simulated moving bed. The method comprises using a coal-based Fischer-Tropsch synthetic oil as a raw material to obtain a target olefin having a carbon number N within a range from 9 to 18, wherein the raw material is subjected to treatment steps including pretreatment, fraction cutting, alkane-alkene separation, and isomer separation, thereby obtaining a high purity α-olefin product. As compared to conventional rectification and extraction processes, the product obtained by the method of the present disclosure has advantages of higher purity, higher yield, lower energy consumption, and significantly reduced production cost.

A process for producing a para-xylene product from a hydrocarbon feed includes: hydrocracking the hydrocarbon feed in the presence of a catalyst to obtain a hydrocracking product; separating the hydrocracking product to obtain a gas stream and a liquid stream, the liquid stream comprising benzene, toluene, xylene, C.sub.9+ hydrocarbon, or a combination comprising at least one of the foregoing; separating the liquid stream to obtain a toluene stream, wherein toluene is present in the toluene stream in an amount equal to or greater than 70 wt %, preferably equal to or greater than 80 wt %, more preferably equal to or greater than 95 wt %, based on the total weight of the toluene stream; and reacting the toluene stream with methanol to obtain the para-xylene product.

A method for the recovery paraxylene with reduced crystallization. Paraxylene is recovered from a mixture of C8 aromatic hydrocarbons in a pressure swing adsorption zone and a crystallization zone. The invention provides for lower throughput through the crystallization zone, resulting in lower capital costs, reduced electricity in operating separation equipment, as well as reduced refrigeration duty.

A method for recovering paraxylene from a mixture of aromatic hydrocarbons. The process uses a pressure swing adsorption zone followed by a paraxylene recovery zone. The invention provides for lower throughput through the paraxylene recovery zone, resulting in lower capital costs and operating costs.

Provided is a method for treating an oil gas, which can realize high-efficiency separation for and recovery of gasoline components, C.sub.2, C.sub.3, and C.sub.4 components. The method first conducts separation of light hydrocarbon components from gasoline components, and then performs subsequent treatment on a stream rich in the light hydrocarbon components, during which it is no longer necessary to use gasoline to circularly absorb liquefied gas components, which significantly reduces the amount of gasoline to be circulated and reduces energy consumption throughout the separation process. Besides, in this method, impurities, such as H.sub.2S and mercaptans, in the stream rich in the light hydrocarbon components are removed first before the separation for the components. This ensures that impurities will not be carried to a downstream light hydrocarbon recovery section, thus avoiding corrosion issues caused by hydrogen sulfide in the light hydrocarbon recovery section.