Pressure swing adsorption recovery

Pressure Swing Adsorption. A number of processes based on Pressure Swing Adsorption (PSA) technology have been used in the production of carbon dioxide. In one version of the PSA process, CO2 is separated from CH using a multibed adsorption process (41). In this process both CH4 and CO2 are produced. The process requires the use of five adsorber vessels. Processes of this type can be used for producing CO2 from natural gas weUs, landfiU gas, or from oil weUs undergoing CO2 flooding for enhanced oil recovery (see Adsorption, gas separation). 

Kikkinides, E.S. Yang, R.T. Cho, S.H. (1993). Concentration and recovery of carbon dioxide from flue gas by pressure swing adsorption. Industrial Engineering Chemistry Research, 32 (11), 2714-2720. 

Recovery and Purification of Light Gases by Pressure Swing Adsorption... 

A cell model is presented for the description of the separation of two-component gas mixtures by pressure swing adsorption processes. Local equilibrium is assumed with linear, independent isotherms. The model is used to determine the light gas enrichment and recovery performance of a single-column recovery process and a two-column recovery and purification process. The results are discussed in general terms and with reference to the separation of helium and methane. 

Pressure swing adsorption (PSA) processes are widely applied industrially for gas separations. Applications are numerous and include hydrogen and helium recovery and purification, air drying, the production of oxygen from air, and the separation of normal paraffins from isoparaffins. 

The equations for a local equilibrium cell model of pressure swing adsorption processes with linear isotherms have been derived. These equations may be used to describe any PSA cycle composed of pressurization and blowdown steps and steps with flow at constant pressure. The use of the equations was illustrated by obtaining solutions for a single-column recovery process and a two-column recovery and purification process. The single-column process was superior in enrichment and recovery of the light component at large product cuts. The two-column process was superior at small cuts ... 

Air Products and Chemicals, Inc. has been selected to supply a hydrocarbon and nitrogen recovery system for a new polyethylene manufacturing plant in Baytown, TX. The plant will be owned by Chevron Phillips Chemical Company and Solvay Polymers, Inc. The recovery system uses partial condensation in conjunction with Air Products pressure swing adsorption technology to recover hydrocarbons in the polyolefin plants, and recycle nitrogen with a purity of greater than 99%55. 

The third process used in the production of carbon dioxide is pressure swing adsorption. The feed gas usually contains approximately 20 percent carbon dioxide, 70 percent hydrogen, and the remainder methane, carbon monoxide, nitrogen, and water. The feed gas is typically under a pressure of 125 100 psig at temperatures of 80-120°F. The carbon dioxide and water are strongly adsorbed in the adsorb beds and the residual gas stream is depressurized for further recovery. The adsorber vessel is then evacuated through vacuum blowers where the carbon dioxide, which has been adsorbed by the bed, is released at purities of essentially 99+ percent pure. 

After further heat recovery, final cooling and condensate separation (6), the gas is sent to the pressure swing adsorption (PSA) unit (7). Loaded adsorbers are regenerated isothermally using a controlled sequence of depressurization and purging steps. 

Pressure swing adsorption (PSA) on zeolite molecular sieves (see Section 4.3.2.6) may be also used for hydrogen recovery from purge gas [761]. The process, originally developed by Union Carbide under the name HYSIV, is now marketed as Polybed PSA by UOP [970], [973], [974], PSA technology is also offered by Linde and other companies. If required, the process also offers the possibility to supply pure hydrogen from... 

McIntyre J. A., Holland C. E., and Ritter J. A., High Enrichment and Recovery of Dilute Hydrocarbons by Dual-Reflux Pressure-Swing Adsorption, Ind. Eng. Chem. Res. 41 (2002) pp. 3499-3504. 

Recoveiy of solvent vapor (dicfaloromethane, CH2CI2) fiom air by pressure swing adsorption (PSA) was studied, using two columns packed with high silica zeolite and resin as adsorbent Gravimetric measurements wete made for dichloromethane on the adsorbents. Computer calculations were carried out to simulate the experimental results using the Stop-Go method to show the calculated results coincide well with experimental results. The method is useful to predict the performance of a solvent recovery system operated by PSA... 

Keefer, B.G. and Doman, D.G. Modular pressure swing adsorption with energy recovery. U.S. Patent 6,051,050, 2000. 

Pressure swing adsorption processes are also designed to produce high-purity (99.95+ %) H2 products from refinery-off gases containing H2 (65-90%) and C1-C5 hydrocarbon impurities with high H2 recoveries ( 86+ %). Silica gel and activated carbons are used as adsorbents. 

Figure 22.3 Schematic drawings of solvent vapor recovery systems (a) conventional thermal swing adsorption, (b) conventional pressure swing adsorption, and (c) rotary adsorber.

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