Organic vapor phase energy

Vapor Permeation Vapor permeation is similar to vapor perva-poration except that the feed stream for permeation is a gas. The futnre commercial viability of this process is based npon energy and capital costs savings derived from the feed already being in the vapor-phase, as in fractional distillation, so no additional heat inpnt wonld be req iired. Its foreseen application areas wonld be the organics recov-eiy from solvent-laden vapors and pollntion treatment. One commercial nnit was installed in Germany in 1989 (Ref. 26). 

Thermochemical data for the solvation of ions as used in the preceding calculations are difficult to measure and even to estimate. Therefore this kind of calculation of AH° for ionic reactions involving organic molecules in solution usually cannot be made. As a result, we have considerably fewer possibilities to assess the thermodynamic feasibility of the individual steps of polar reactions in solution than we do of vapor-phase radical processes. Bond energies are not of much use in predicting or explaining reactivity in ionic reactions unless we have information that can be used to translate gas-phase AH°. values to solution AH° values. Exercise 8-3 will give you a chance to see how this is done. 

Castorina et al (Refs 164 180) studied the surface activity of one-micron size a-HMX as a function of Co60 gamma dose in vacuo and vapors of H20, NO and N02. The production of polar surface adducts suggests that the mechanism of energy transfer from the bulk of the substrate to the surface-vapor phase interface be postulated to apply to crystalline organic substrates. By this mechanism changes in surface properties can be achieved without any serious... 

XeF2 also acts as a mild fluorinating agent for organic compounds for example, in solution or in the vapor phase benzene is converted into QH5F. The dissociation energy of XeF2 to XeF + F is ca. 252 kJ mol-1.11... 

The liquid solvent added to a pharmaceutical material generally exists in a variety of states. Some will condense or be pulled by capillary forces into macroscopic pores and fissures or into the interstitial spaces between particles. A state of local equilibrium can be assumed to exist at the interface between the liquid and vapor phases of solvent so situated. As a result, the temperature and vapor pressure exerted by the condensed solvent will not be independent of one another. Fig. 4 shows the equilibrium vapor pressure vs. temperature relationship for a number of common solvents. Heats of vaporization are shown parenthetically. Among common solvents, acetone has the highest vapor pressure and water the lowest. Water requires three-five times the energy of the common organic solvents to vaporize. 

There are four vapor phase treatment processes (a) thermal destruction, (b) catalytic incinerahon, (c) ozone destruction with ultraviolet radiation, and (d) granular carbon adsorption (GAC). Processes a-c are not widely utilized due to cost and/or effectiveness of treatment. Thermal destruction is an effective process, but the operating cost is very high due to energy requirements. Catalytic incineration, shown in Fig. 7, has lower energy requirements compared to the thermal destruction process, but it is not effective in eliminating low levels of chlorinated organic compounds. Ozone destruction with an ultraviolet radiation process has limited performance data available as a result, the performance of this process must be examined in a pilot study for the particular VOC in question in order to determine operational parameters. The most commonly used vapor phase treatment process for VOC is carbon adsorption. 

When a solid powder is used as the stationary phase in the inverse gas chromatography method, the interaction of a well-known gas or organic vapor is measured, and the adsorption results for gaseous molecules on the solid powder are used to calculate the difference in surface free energy of bare stationary solid surface and that of the solid-vapor interface (ys - ysv). 

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