Hydrocarbons in gas

The excited I (2Pi/2) has enough energy to abstract H atom from a hydrocarbon in gas phase reactions... 

Acid Form - Pseudoliquid Phase Behavior. Owing to a high affinity for polar molecules, large quantities of molecules such as alcohols and ether are absorbed within the bulk phase of crystalline heteropolyacids. The amounts of pyridine, methanol, and 2-propanol absorbed correspond to 50-100 times that which can be adsorbed on the surface, while nonpolar molecules like ethylene and benzene are adsorbed at the surface only. Catalytic reactions of polar molecules occiu both on the surface and in the bulk, so that the solid heteropolyacid behaves as a highly concentrated solution, called a pseudoliquid phase . The dehydration of alcohols, various conversions of methanol and dimethyl ether to hydrocarbons in gas-solid systems, and the alkylation of phenol and pinacol rearrangements can all occur in the pseudoliquid. The transient response using isotopically labeled 2-propanol provides evidence for the pseudoliquid phase behavior of H3PW12O40. This behavior influences the selectivity, for example, the aUcene/aUcane ratio, in the conversion of dimethyl ether. 

Gas Purification. The best-known purification process using 4A is that of natural gas this involves two benefits, namely, peak-shaving whereby the calorific value of fhe gas is adjusted by CO2 (and water) removal, and sweetening by H2S removal. The latter purification also is used in LPG treatment. Another example is the trapping of hydrocarbons in gas and vacuum circuits. 

Total concentration of two hydrocarbons in gas phase was 2000 ppm (0.2 kPa). The mole fraction of 224 trimethylpentane and toluene was assumed of 0.5 and 0.5, respectively. The concentration of supplied O2 concentration was 0.18 kPa, and the velocity was 7.57E-2 m/s. In all cases, 224 trimethylpentane was emitted first, but the reaction was started lately. It matches to the results of adsorption equilibrium and conversion experiments. The proposed model described the experimental data properly. 

Other characteristics Hydrocarbons in gas Hydrocarbons in gas Lower carbon conversion Lower carbon conversion Pure gas, high carbon conversion... 

The activity of Uiis type of catalyst in the oxidation of different hydrocarbons in gas mixtures at stoichiometry was next determined in the new or aged state. Irrespective of the natine of the hydrocarbons, their conversion gradually decreases in keeping with the decrease in metal dispersion. This decrease in conversion can be explained by the loss of active sites when sintering takes place. 

The results of these determinations for 22 elements on 88 crude oils were subjected to factor analysis, which is a statistical technique designed to explain complex relations among many variables in terms, of a few factors which themselves represent simpler relations among fewer variables. Factor analysis only determines the relations it does not explain them. The explanation of the factors must be in the context of known information about the variables. Hitchon and Gawlak have used factor analysis in the study of aromatic hydrocarbons in gas condensates from Alberta and their paper includes pertinent background information with particular application to geochemical problems. 

Lawther, P.J., Commins, B.T., and Waller R.E. A study of the concentrations of polycyclic aromatic hydrocarbons in gas works retort houses 1965, British Journal of Industrial Medicine... 

K. D. Bartle, M. L. Lee and S. A. Wise, Factors affecting the retention of polycyclic aromatic hydrocarbons in gas chromatography, Chromato-graphia, 1981, 14, 69-72. 

Both CA and polyimides are susceptible to plasticization by CO2 [25-27]. When CO2 solnbihzes in the polymer matrix the polymer chains become more flexible and allow faster transport of CO2 molecules. If other gas molecules such as methane or nitrogen are present they also increase their transport rate often even more so than CO2. This means that mixed gas measurements often generate lower a than pure gas. Also, if pure gas measurements are done then methane is usually measured before CO2 since the polymer remembers exposure to CO2 and needs time to relax the extra free volume that has been created. Various studies have documented the response of CA permeation rates to tem-peratnre, pressure and CO2 concentration [28-31]. When pressure is increased more CO2 solubilizes in the polymer matrix increasing this plasticization. Going up in temperature also softens the polymer and causes loss of a. In addition, common heavy hydrocarbons in gas fields such as hexane or toluene can negatively impact performance of polyimides in treating natural gas [32-34]. 

The same tendency is observed at comparing the experimental results from the ozonolysis of acyclic hydrocarbons in gas phase [2-10] and in an inert solvent - CCl [47]. The ratio of the preexponential factors in them is in the range of 2-3. 

Castro, D., Slezakova, K., Delerue-Matos, C., Alvim-FerrazM., Morais, S. Pereira, M.C.2011.Polycyclic aromatic hydrocarbons in gas and particulate phases of indoor environment influenced by tobacco smoke levels, phase distribution and health risks. Atmospheric Environment 1799-1808. 

Berngard, A., Colmsjo, A., and Wrangskog, K. (1994) Prediction of temperature-programmed retention indexes for polynuclear aromatic hydrocarbons in gas chromatography. 

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