Inorganic gases, mixtures

Takano, Y. Ohashi, A. Kaneko T. Kobayashi, K. Abiotic synthesis of high-molecular-weight organics from an inorganic gas mixture of carbon monoxide, ammonia and water by 3 MeV proton irradiation. Appl. Phys. Lett. 2004, 84, 1410-1412. 

The removal of one or more components from a gas mixture by absorption is probably the most important and familiar operation in the control of gaseous pollutant emissions. Though most often used for the control of inorganic gases, absorption can also be used for recovery of organic compounds. Absorption in-... 

This chapter will only deal with the possible gas transport mechanisms and their relevance for separation of gas mixtures. Beside the transport mechanisms, process parameters also have a marked influence on the separation efficiency. Effects like backdiffusion and concentration polarization are determined by the operating downstream and upstream pressure, the flow regime, etc. This can decrease the separation efficiency considerably. Since these effects are to some extent treated in literature (Hsieh, Bhave and Fleming 1988, Keizer et al. 1988), they will not be considered here, save for one example at the end of Section 6.2.1. It seemed more important to describe the possibilities of inorganic membranes for gas separation than to deal with optimization of the process. Therefore, this chapter will only describe the possibilities of the several transport mechanisms in inorganic membranes for selective gas separation with high permeability at variable temperature and pressure. 

The gas-liquid permporometry combines the controlled stepwise blocking of membrane pores by capillary condensation of a vapor, present as a component of a gas mixture, with the simultaneous measurement of the free diffusive transport of the gas through the open pores of the membrane. The condensable gas can be any vapor provided it has a reasonable vapor pressure and does not react with the membrane. Methanol, ethanol, cyclohexane and carbon tetrachloride have been used as the condensable gas for inorganic membranes. The noncondensable gas can be any gas that is inert relative to the membrane. Helium and oxygen have been used. It has been established that the vapor pressure of a liquid depends on the radius of curvature of its surface. When a liquid is contained in a capillary tube, this dependence is described by the Kelvin equation, Eq. (4-4). This equation which governs the gas-liquid equilibrium of a capillary condensate applies here with the usual assumption of a=0 ... 

Asaeda M and Yamasaki S. Separation of inorganic/organic gas mixtures by porous silica membranes. Sep. Purif. Technol. 2001 25 151-159. 

Since dissolved inorganic carbon, such as free CO2 and bicarbonate, acts as a sole carbon source in photoautotrophic growth of microalgae, the partial pressure of CO2 in the atmosphere or in the supplied gas mixture is an important factor for their growth. Studies on the mechanisms underlying the efficient photosynthesis of microalgae in air level CO concentration (L-COj, 0.036%) will be described. 

M. Hassan, J.D. Way, P.M. Thoen and A.C. Dillon, Separation of gas mixtures using hollow fiber silica membranes, in Y.H. Ma (Ed.), Proceedings of 3rd International Conference on Inorganic Membranes (ICIM3), July 10-14,1994, Worcester, MA, USA. Distributed by Worcester Polytechnic Institute, 100 Institute Rd. Worcester, MA 01609, USA. pp. 325-335. 

Removal of trace organic and inorganic impurities from a gas stream by an activated carbon is one of the oldest appH cations of adsorption technology. The other applications of Table 22.1 where the adsorbed components are present in dilute or bulk quantities in the feed gas mixture were developed during the last 30 years. 

Eiceman, G.A., Leasure, C.S., Vandiver, V.J. Negative ion mobility spectrometry for selected inorganic pollutant gases and gas mixtures in air. Anal. Chem. 58, 76-80, 1986. 

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