Abstract: Olefins are recovered from thermally cracked gas or fluid catalytic cracking off gas by cooling the gas to condense a portion of the hydrocarbons, removing hydrogen from the noncondensed gas, and condensing the remaining hydrocarbons in a cold condensing zone using a dephlegmator which operates above about -166.degree. F. This mode of operation minimizes the amount of methane in the condensate which is further processed in demethanizer column(s) and permits the condensation of ethylene at warmer temperatures than possible using a partial condenser in the cold condensing zone. The use of a dephlegmator at temperatures above about -166.degree. F. minimizes or eliminates the formation and accumulation of unstable nitrogen compounds in the ethylene recovery system. Hydrogen is removed from the noncondensed gas in a process selected from polymeric membrane permeation, adsorptive membrane permeation, or pressure swing adsorption.

Abstract: Light components are stripped from a multicomponent liquid feed mixture in a core type plate-fin heat exchanger by heating and partially vaporizing the mixture during downward flow in one of a plurality of multichannel flow passageways in the exchanger. The vapor thus formed flows upward and promotes vaporization of dissolved light components from the liquid to yield a liquid product substantially free of lighter components. The passageways are disposed in indirect heat exchange with one or more additional groups of passageways, and heat for partial vaporization of the downward-flowing liquid feed mixture is provided by indirect heat exchange with a condensing process stream. Alternatively, this heat is provided by a bottoms stream recovered from distillation of the stripped liquid product withdrawn from the core type plate-fin heat exchanger.

Abstract: Hydrocarbons are recovered from the product purge gas in an alkene polymerization process by absorption of heavier hydrocarbons from the purge gas by an intermediate hydrocarbon stream to yield a vapor rich in inert gas and alkene monomer. Alkene monomer is condensed at low temperatures from the inert gas, flashed and vaporized to provide refrigeration for the condensation step, and recycled to the polymerization process. The intermediate hydrocarbon from the absorption step is recycled to the polymerization process. Optionally a portion of the inert gas is reused for purge gas.

Abstract: A closed-loop mixed refrigerant cycle provides efficient low-level refrigeration for recovering ethylene from a mixed gas feed. Compressed mixed refrigerant vapor is condensed at -20.degree. F. to -50.degree. F. and is subcooled to -175.degree. F. to -225.degree. F. by indirect heat exchange with cold H.sub.2, methane, and expander streams from elsewhere in the ethylene plant. A portion of the subcooled refrigerant may be flashed to provide additional subcooling of the main mixed refrigerant stream. Subcooled mixed refrigerant is subsequently flashed to provide very low temperature level refrigeration for feed condensation and demethanizer overhead condenser duties. The invention allows advantageous operation of the feed chilling train at pressures between 150 and 400 psia.

Abstract: Refrigeration is provided in an ethylene recovery plant by an open-loop mixed refrigeration cycle which utilizes components present in the ethylene-containing feed gas as the mixed refrigerant. Refrigeration is provided by subcooled mixed refrigerant at -175.degree. to -225.degree. F. for the demethanizer overhead condenser and for initial cooling and condensation of the ethylene-containing feed gas. Overall ethylene recoveries of up to 99.9% can be achieved at reduced power consumption compared with conventional ethylene recovery cycles. In addition, significant capital savings can be realized due to the simplification of equipment with the open-loop mixed refrigerant cycle, which can be operated advantageously at pressures between 150 and 400 psia.

Abstract: A closed-loop mixed refrigerant cycle provides efficient low-level refrigeration for recovering ethylene from a mixed gas feed. Compressed mixed refrigerant vapor is condensed at -20.degree. F. to -50.degree. F. and is subcooled to -175.degree. F. to -225.degree. F. by indirect heat exchange with cold H.sub.2, methane, and expander streams from elsewhere in the ethylene plant. A portion of the subcooled refrigerant may be flashed to provide additional subcooling of the main mixed refrigerant stream. Subcooled mixed refrigerant is subsequently flashed to provide very low temperature level refrigeration for feed condensation and demethanizer overhead condenser duties.

Abstract: Refrigeration is provided in an ethylene recovery plant by an open-loop mixed refrigeration cycle which utilizes components present in the ethylene-containing feed gas as the mixed refrigerant. Refrigeration is provided by subcooled mixed refrigerant at -175.degree. to -225.degree. F. for the demethanizer overhead condenser and for initial cooling and condensation of the ethylene-containing feed gas. Overall ethylene recoveries of up to 99.9% can be achieved at reduced power consumption compared with conventional ethylene recovery cycles. In addition, significant capital savings can be realized due to the simplification of equipment with the open-loop mixed refrigerant cycle.

Abstract: Ethylene-containing feed gas to a cryogenic ethylene recovery system is cooled and condensed, prior to fractionation, by an improved method which utilizes a combination of one or more partial condensers followed by one or more dephlegmators. The improved method simplifies heat exchange equipment and reduces capital cost, and is particularly suited for processing a pressurized precooled feed gas from ethane cracking which contains less than about 1 mole % of propane plus propylene.

Abstract: A process for cooling, phase separating, rectifying and stripping a hydrocarbon containing feed gas stream to recover a heavy hydrocarbon product wherein a predominant amount of the refrigeration for the process is provided from a single loop vapor recompression refrigerator employing a mixed refrigerant.

Abstract: The present invention is an energy efficient process for the recovery and purification of C.sub.3.sup.+ hydrocarbons from a high pressure natural gas or refinery/petrochemical feed gas containing C.sub.3.sup.+ hydrocarbons and light gases. In the process, the high pressure feed gas is initially cooled by heat exchange with a multi-component refrigerant fluid circulating in a closed-loop cycle thereby condensing a large portion of the C.sub.3.sup.+ hydrocarbons. The non-condensed, remaining gas is work expanded to an intermediate pressure thus providing refrigeration for condensing the remaining C.sub.3.sup.+ hydrocarbons. The condensed C.sub.3.sup.+ hydrocarbon liquid streams are combined and are further purified by distillation in an integrated distillation column. Optically, refrigeration for refluxing the integrated distillation column can be provided by the mixed refrigerant cycle.

Abstract: The process of this invention is a hybrid gas separation process which recovers both heavy hydrocarbon and high purity hydrogen products from a gas stream containing a relatively low concentration of hydrogen. The heavy hydrocarbon product may consist of C.sub.2 +, C.sub.3 + and/or C.sub.4 + hydrocarbons. The light hydrocarbons and other light components, such as N.sub.2 and CO, are removed as a light fuel gas stream. After convertional removal of any components which might freeze at low temperatures, the feed gas is combined with recycle gas from the hydrogen purifier and fed to the cryogenic unit.

Abstract: The invention provides a liquids recovery process useful for the separation and recovery of C.sub.3.sup.+ liquid hydrocarbons from gas mixtures containing high concentrations of lighter components such as are produced by the dehydrogenation of liquefied petroleum gases or by the catalytic cracking of heavy oils. The recovery process employs an absorption refrigeration cycle to supply high level refrigeration to the process; the absorption cycle utilizes low pressure steam or a heated fluid derived from secondary heat recovery of a process flue gas to effect heating in the absorption refrigeration cycle.

Abstract: A process is disclosed for the rejection of nitrogen from natural gas with the optional recovery of natural gas liquids. The process of the present invention employs a dephlegmator which provides a high purity nitrogen reflux for a low pressure distillation column and provides subcooling of the feed and reflux to the low pressure column and reboiling of the low pressure column. The dephlegmator of the present invention combines the high pressure column and three heat exchangers of a conventional double column process into a single, compact unit, with corresponding reductions in interconnecting piping and capital investment.

Abstract: A low capital cost, energy efficient process for separation of carbon dioxide, sulfide gases and hydrocarbons from carbonaceous off-gas streams, for example, oil shale retorting off-gases, coal gasification off-gases, oxygen fire flooding off-gases or carbon dioxide miscible flood enhanced oil recovery off-gases is disclosed. The process comprises separation of the off-gases into an essentially sulfur-free light fuel gas, a heavy hydrocarbon stream and a carbon dioxide gas stream wherein the off-gas is compressed if necessary and cooled prior to separation of the various streams in a distillation column. The carbon dioxide stream is expanded in an auto-refrigeration step to provide some of the necessary process refrigeration.

Abstract: The present invention relates to a process for the recovery of ethylene from a feed gas containing ethane, methane and other light gases, e.g. cracked gas or refinery off-gases, wherein ethylene is condensed in two stages, preferably rectified, and fed to an integrated demethanizer column. Refrigeration for the process is provided by an integrated combination of work expansion of rejected light gases, by vaporization of separated ethane at low partial pressure but high total pressure, and by a mixed refrigerant system. The process results in the separation and purification of ethylene from the feed gas stream while significantly reducing the energy consumption to do so.

Abstract: A low temperature phase separation, dephlegmation and distillation process is described for resolving a light hydrocarbon gas stream to recover and purify C.sub.3+ and/or C.sub.4+ hydrocarbons. The phase separation bottoms stream is segregated from the dephlegmation bottoms stream and both streams are expanded to produce refrigeration for the feed stream. Both streams are then separately introduced into a distillation column for final purification of the heavy hydrocarbon product.

Abstract: The present invention is a process for phase separating, dephlegmating and optionally distilling a feed gas stream to recover a light gas product and a heavy hydrocarbon product wherein a predominant amount of the refrigeration for the process is provided by a two temperature and two pressure stage multicomponent closed-circuit refrigeration cycle.

Abstract: The present invention involves a process for separating and purifying gas mixtures comprising H.sub.2, CO and C.sub.1 + hydrocarbons. The gas is initially cooled in a high pressure dephlegmator to condense and rectify the C.sub.1 + hydrocarbons leaving a combined H.sub.2 --CO vapor. The condensed C.sub.1 + hydrocarbons are partially vaporized and subsequently recondensed in a second, low pressure dephlegmator with further rectification. This process yields H.sub.2 --CO vapor streams and a C.sub.1 + liquid hydrocarbon product at purities suitable for subsequent commercial operations.

Abstract: A process is described for separating C.sub.4 + hydrocarbons in high recovery and high purity from a feed gas comprising about 0-5% C.sub.5 and heavier hydrocarbons, 1-10% C.sub.4 hydrocarbons, 0-10% C.sub.3 hydrocarbons, 0-10% C.sub.2 hydrocarbons and the balance CH.sub.4 and light inerts. Efficient separation is effected by using a dephlegmator cycle employing only internal refrigeration.

Abstract: This invention relates to a distillation system for effecting separation of a multicomponent fluid and to an improved bubble-cap design which can accommodate very wide ranges of vapor and liquid loadings. A portion of the tray is provided with bubble caps having first and second slot openings with the second slot opening at an elevation higher than the first opening.