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Process configuration alternatives for separation of gas mixtures by complementary pressure swing adsorption
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K.S. Knaebel, Department of Chemical Engineering, The Ohio State University, Columbus, OH 43210, U.S.A.: Process Configuration Alternatives for Separation of Gas Mixtures by Complementary Pressure Swing Adsorption Complementary pressure swing adsorption (CPSA) is a modification of conventional pressure swing adsorption that employs two adsorbents of inverse selectivity for the components of a binary mixture. Four distinct CPSA configurations have been developed and are examined theoretically for a range of operating conditions, adsorbent characteristics, and feed compositions. Results indicate that complete separation is possible with one of the systems, such that no impure by-products are generated. The other three systems generate enriched by-products that are typically less than for independent systems, although one or both of the main products may also be impure. All four configurations may offer advantages for certain applications depending on the feed and desired product compositions and their relative values, and the compression and capital costs. A specific example of splitting air to yield enriched oxygen and nitrogen is analyzed and discussed. Submitted to Industrial and Engineering Chemistry, Process Design and Deuelopment.
M.B. Kril, G.E. Janauer and T. Fitzpatrick, Department of Chemistry, University Center at Binghamton, State University of New York, Binghamton, NY 13901, and R.L. Sauer, NASA, Lyndon B. Johnson Space Center, Houston, TX 77059, U.S.A.: Effect of Microbial Fouling on Dynamic Column Capacities of Activated Charcoal and Ion Exchange Resins There is a growing interest in point-of-use water treatment for both chemical and microbial purity. To this date no single approach has met with universal approval, but chemical purification usually involves the use of an effective sorbent, such as activated charcoal or ion-exchange resins. Microorganisms have been known to adsorb to activated charcoal, ion-exchange resins and other solid sorbents. These materials, when applied in columns, can facilitate microbial growth due to co-adsorption of organic and inorganic matter which may serve as nutrients. A reduction of the dynamic column capacity of sorbent and exchange materials may occur due to "microbial fouling" which is, probably, enhancing any such effects due to organic fouling. The results of a number of experiments with microorganisms (both viable and devitalized) and activated charcoal and ion-exchange resins are discussed as related to changes in the dynamic adsorption or exchange capacity of these materials, along with some new possibilities for the prevention of microbial colonization of ion-exchange and charcoal columns. Unpublished.
D.P. Condo, G.E. Janauer and R. Rossi, Department of Chemistry, University Center at Binghampton, State University of New York, Binghamton, NY 13901, U.S.A.: Reactive Preconcentration of Carbamate Pesticide Traces Prior to Indirect Spectrophotometry HPLC and GC aided by suitable preconcentration or cleanup techniques are presently the preferred methods for organic pollutant quantitation. Trained personnel and state-of-the-art instrumentation are required. Mounting concern over monitoring chemical pollution throughout the U.S.A. suggests a need for inexpensive, simple and rapid quantitative or at least "threshold" (semiquantitative) tests for pollutants. Techniques such as spectrophotometry have low cost and can be applied routinely. Unfortunately, in most cases, the detection limits (DL) are not adequate for thc determination of sub-ppm and ppb levels of pollutants. Reactive preconcentration can overcome this problem for a number of important contaminants. Lower DL for trace preconcentration and greatly improved selectivity for target analyte groups can accrue from the use of reactive polymers. The indirect spectrophotometric determination of carbamate pesticides can serve as an example of the kinds of procedures that may facilitate and reduce the cost of diagnostic environmental testing for toxic, reactive species at trace levels. To be published in The Ana&st
K.S. Knaebel, Department of Chemical Engineering, The Ohio State University, Columbus, OH 43210, U.S.A.: Process Configuration Alternatives for Separation of Gas Mixtures by Complementary Pressure Swing Adsorption Complementary pressure swing adsorption (CPSA) is a modification of conventional pressure swing adsorption that employs two adsorbents of inverse selectivity for the components of a binary mixture. Four distinct CPSA configurations have been developed and are examined theoretically for a range of operating conditions, adsorbent characteristics, and feed compositions. Results indicate that complete separation is possible with one of the systems, such that no impure by-products are generated. The other three systems generate enriched by-products that are typically less than for independent systems, although one or both of the main products may also be impure. All four configurations may offer advantages for certain applications depending on the feed and desired product compositions and their relative values, and the compression and capital costs. A specific example of splitting air to yield enriched oxygen and nitrogen is analyzed and discussed. Submitted to Industrial and Engineering Chemistry, Process Design and Deuelopment.
M.B. Kril, G.E. Janauer and T. Fitzpatrick, Department of Chemistry, University Center at Binghamton, State University of New York, Binghamton, NY 13901, and R.L. Sauer, NASA, Lyndon B. Johnson Space Center, Houston, TX 77059, U.S.A.: Effect of Microbial Fouling on Dynamic Column Capacities of Activated Charcoal and Ion Exchange Resins There is a growing interest in point-of-use water treatment for both chemical and microbial purity. To this date no single approach has met with universal approval, but chemical purification usually involves the use of an effective sorbent, such as activated charcoal or ion-exchange resins. Microorganisms have been known to adsorb to activated charcoal, ion-exchange resins and other solid sorbents. These materials, when applied in columns, can facilitate microbial growth due to co-adsorption of organic and inorganic matter which may serve as nutrients. A reduction of the dynamic column capacity of sorbent and exchange materials may occur due to "microbial fouling" which is, probably, enhancing any such effects due to organic fouling. The results of a number of experiments with microorganisms (both viable and devitalized) and activated charcoal and ion-exchange resins are discussed as related to changes in the dynamic adsorption or exchange capacity of these materials, along with some new possibilities for the prevention of microbial colonization of ion-exchange and charcoal columns. Unpublished.
D.P. Condo, G.E. Janauer and R. Rossi, Department of Chemistry, University Center at Binghampton, State University of New York, Binghamton, NY 13901, U.S.A.: Reactive Preconcentration of Carbamate Pesticide Traces Prior to Indirect Spectrophotometry HPLC and GC aided by suitable preconcentration or cleanup techniques are presently the preferred methods for organic pollutant quantitation. Trained personnel and state-of-the-art instrumentation are required. Mounting concern over monitoring chemical pollution throughout the U.S.A. suggests a need for inexpensive, simple and rapid quantitative or at least "threshold" (semiquantitative) tests for pollutants. Techniques such as spectrophotometry have low cost and can be applied routinely. Unfortunately, in most cases, the detection limits (DL) are not adequate for thc determination of sub-ppm and ppb levels of pollutants. Reactive preconcentration can overcome this problem for a number of important contaminants. Lower DL for trace preconcentration and greatly improved selectivity for target analyte groups can accrue from the use of reactive polymers. The indirect spectrophotometric determination of carbamate pesticides can serve as an example of the kinds of procedures that may facilitate and reduce the cost of diagnostic environmental testing for toxic, reactive species at trace levels. To be published in The Ana&st