摘要:
Provided are systems and methods for separating a purge gas recovered from a polyethylene product. The method includes recovering a polyethylene product containing one or more volatile hydrocarbons from a polymerization reactor and contacting the polyethylene product with a purge gas to remove at least a portion of the volatile hydrocarbons to produce a polymer product having a reduced concentration of volatile hydrocarbons and a purge gas product enriched in volatile hydrocarbons. The purge gas product is compressed to a pressure of 2,500 kPaa to 10,000 kPaa, and is then cooled and separated into at least a first product, a second product, and a third product. A portion of one or more of the first, second, or third products is then recycled as a purge gas, to the polymerization reactor, or to the purge gas product enriched in volatile hydrocarbons prior to compression, respectively.
摘要:
A first nitrogen stripper feed stream is fed into a nitrogen stripper column at a stripping pressure. A nitrogen-stripped liquid is drawn from a sump space of the nitrogen stripper column, depressurized to a flash pressure that is lower than the stripping pressure, and fed to an end flash separator. A liquefied hydrocarbon product stream is discharged from the end flash separator, as well as a process vapour. The process vapour is compressed to at least the stripping pressure, and, split in a stripping vapour stream and a fuel gas vapour stream. The stripping vapour stream is fed into the nitrogen stripper column, while the fuel gas vapour stream is passed to a gas turbine. Another fuel gas, having a lower heating value, is obtained from the overhead vapour from the nitrogen stripper column. This other fuel gas is combusted in a combustion device other than a gas turbine.
摘要:
A multi-phase hydrocarbon stream (145) is treated to provide a treated liquid hydrocarbon stream (165), such as a liquefied natural gas (LNG) stream. The multi-phase hydrocarbon stream (145) is passed to a first gas/liquid separator (150), wherein it is separated at a first pressure to provide a first separator hydrocarbon vapour stream (205) and a first separator bottoms stream (155). The first separator bottoms stream (155) is then separated in a second gas/liquid separator (160) at a second pressure that is lower than the first pressure, to provide a second separator hydrocarbon vapour stream (175) and a treated liquid hydrocarbon stream (165). The second separator hydrocarbon vapour stream (175) is compressed in an overhead stream compressor (180) to provide a stripping vapour stream (185) which is passed to the first gas/liquid separator (150).
摘要:
In a hydrocarbon synthesis process, nitrogen is cryogenically removed from natural gas to produce a synthesis gas feed comprising methane which is substantially free of nitrogen. This feed is converted to a synthesis gas comprising a mixture of H2 and CO which is substantially free of the HCN and NH3 hydrocarbon synthesis catalyst deactivating nitrogen species. This reduces the need for rejuvenating the hydrocarbon synthesis catalyst. During the cryogenic separation, C2+ hydrocarbons are separated from the natural gas and all or a portion of the separated C2-C4 hydrocarbons are added to the methane feed before it is converted into syngas, to increase syngas production. All or a portion of the separated C2-C3 hydrocarbons may be removed as LPG.
摘要:
A process for the extraction and recovery of ethane and heavier hydrocarbons (C2+) from LNG. The process covered by this patent maximizes the utilization of the beneficial cryogenic thermal properties of the LNG to extract and recover C2+ form the LNG using a unique arrangement of heat exchange equipment, a cryogenic fractionation column and processing parameters that essentially eliminates (or greatly reduces) the need for gas compression equipment minimizing capital cost, fuel consumption and electrical power requirements. This invention may be used for one or more of the following purposes: to condition LNG so that send-out gas delivered from an LNG receiving and regasification terminal meets commercial natural gas quality specifications; to condition LNG to make Lean LNG that meets fuel quality specifications and standards required by LNG powered vehicles and other LNG fueled equipment; to condition LNG to make Lean LNG so that it can be used to make CNG meeting specifications and standards for commercial CNG fuel; to recover ethane, propane and/or other hydrocarbons heavier then methane from LNG for revenue enhancement, profit or other commercial reasons.
摘要:
Liquefied natural gas (LNG) is heated in a plant by a heat source and the heated LNG is expanded to produce work. In particularly preferred plants, the heat source is a combined cycle power plant, and the work is used to recompress pipeline gas produced from the heated LNG. Additionally, the refrigeration content in LNG may be utilized to increase the power generation capacity and efficiency of a combined cycle power plant.
摘要:
Provided is a method of producing gas hydrate at a low cost. An acid gas 3 is removed from a natural gas 1, and after dehydration 5 of accompanying water, part of heavy components 7 which do not produce gas hydrate 10 are separated and removed under a relatively high temperature. Moreover, the rest of the heavy components are taken out in a gas hydrate production step 9 together with an excessive portion of light components not contributing to production of the gas hydrate 10, as a fuel gas 11 which is used as a cooling source or a power source for a cooling system in the gas hydrate production step 9.
摘要:
A method of cooling a hydrocarbon stream such as natural gas, the method at least comprising the steps of: (a) separating a feed stream (10) into a gaseous stream (130) and a liquid stream (70); (b) compressing the gaseous stream (130) to provide a compressed gaseous stream (150); (c) dividing the compressed gaseous stream (150) into at least a first stream (170) and a second stream (160); (d) cooling, preferably liquefying, the first stream (170) to provide a cooled hydrocarbon stream; and (e) removing the second stream (160).
摘要:
A method for recovering krypton and xenon from air comprises (a) separating an air feed stream (301) into oxygen-enriched (103) and nitrogen-enriched product streams (305); (b) reacting the oxygen-rich product stream with a hydrocarbon feed (101) in a synthesis gas generation process (105) to yield a synthesis gas stream (107) comprising hydrogen, carbon oxides, krypton, and xenon, which synthesis gas stream contains essentially no oxygen; (c) introducing the synthesis gas stream (107) into a synthesis gas conversion process (311) and converting the synthesis gas stream into a liquid synthesis product stream (321) and an unreacted synthesis gas stream (323); (d) recycling at least a portion (325) of the unreacted synthesis gas stream (323) to the synthesis gas generation process (105); (e) reducing the pressure (401) of the liquid synthesis product stream (321) to yield a two-phase reduced-pressure product stream (403), and separating (405) the two-phase reduced-pressure product stream into a final liquid synthesis product stream (409) and a gas stream enriched in krypton and xenon (407); and (f) separating the gas stream enriched in krypton and xenon into a purge gas stream (113) and a gas product stream (111) further enriched in krypton and xenon.