Abstract: A process and system for providing cooling service (refrigerant) for a gas separation process wherein the refrigerant is obtained from the system process fluid and after serving as refrigerant is returned to the process side for separation into product.

Abstract: A distillation process and apparatus for recovering high purity aromatic products from a mixed aromatic hydrocarbon feedstock containing benzene, toluene and xylene by use of distillation towers integrated by heat exchange whereby substantial savings in operating costs and apparatus costs are realized. The distillation apparatus includes a benzene distillation tower and heat exchanger, a first toluene distillation tower and external heater, a second toluene distillation tower and heat exchanger and a xylene distillation tower and external heater, whereby the benzene distillation tower and heat exchanger are operably connected to the first toluene distillation tower and external heater and the second toluene distillation tower and heat exchanger are operably connected to the xylene distillation tower and external heater.

Abstract: A cryogenic technique for recovering pure products from a mixture of at least three close-boiling components. A preferred process is provided for separating a hydrocarbon mixture containing an alkene (i.e. ethene or propene), corresponding alkane having the same number of carbon atoms and at least one heavier hydrocarbon component. The improved process comprises: feeding the hydrocarbon mixture to a first distillation tower having an upper reflux stage; recovering a first overhead vapor stream rich in alkene and alkane from the first distillation tower and passing the first overhead vapor stream to a middle distillation stage of a second multi-stage distillation tower; recovering a second overhead vapor stream rich in alkene from the second distillation tower; adiabatically compressing the alkene-rich vapor stream and passing the compressed vapor to a second distillation tower reboiler stage. This provides a heat pump for cooling and condensing the compressed vapor and heating a liquid reboiler stream.

Abstract: An improved aromatization apparatus is disclosed in which conversion is increased by recycling a highly purified C.sub.2 -C.sub.4 aliphatic stream. Loss of valuable ethane to fuel gas is substantially eliminated. In a preferred embodiment, a dephlegmator purifies the C.sub.2 -C.sub.4 recycle stream.

Abstract: An improved aromatization process is disclosed in which conversion is increased by recycling a highly purified C.sub.2 -C.sub.4 aliphatic stream. Loss of valuable ethane to fuel gas is substantially eliminated. In a preferred embodiment, a dephlegmator purifies the C.sub.2 -C.sub.4 recycle stream.

Abstract: A cyrogenic technique for recovering ethene from a gaseous mixture containing methane, ethane, etc. Operating methods and apparatus are provided for passing the gas feed through a chilling train having a series of dephlegmator-type exchange units to condense liquid rich in ethene and ethane, while separating a major portion of methane and lighter gas. A multizone demethanizer removes condensed methane from the C.sub.2 fraction to provide a pure product economically.

Abstract: There is disclosed a process for recovering olefin monomers, e.g., C.sub.3 -C.sub.10 alpha-olefins, from a vent gas of a vapor phase process for polymerizing olefins. The method comprises passing the vent gas, obtained by purging a resin produced in the polymerization process with an inert gas, such as nitrogen, into contact with an adsorbent to effect the adsorption of an olefin monomer. Subsequently, the adsorbed monomer is removed by contacting the adsorbent with a second monomer having lower molecular weight than the adsorbed monomer.