Catalytic benefits

Indeed, this evidence suggests that the mineral matter can be beneficial in increasing both the conversion and liquid product yields. From a processing viewpoint, high mineral matter can create other problems, and a trade off between possible catalytic benefits and engineering process difficulties is necessary. 

It is nevertheless certainly useful and interesting to study the catalytic benefit of forming a potentially more reactive conformation of the substrate. Many modelling... 

QM/MM (AM1/CHARMM) or empirical valence bond methods, respectively164 168), for forcing the conformation of chorismate in solution into the more restricted conformation found in the enzyme. This equates to a catalytic benefit of only around 40-55% of the total AA G between enzyme and solvent. The good agreement between these findings, which applied completely different theoretical methods, is striking and suggests that this is a reliable result. 

GoneU S, Poyatos M, Peris E. Triphenylene-based tris(N-heterocychc carbene) Ugand unexpected catalytic benefits. Angew Chem Ini Ed Engl. 2013 52 7009-7013. 

The molecular emphasis of modem chemisorption studies has benefited the field of catalysis by giving depth and scope to the surface chemistry of catalytic processes. To paraphrase King [1], quantitative answers have become possible to the following questions ... 

A great deal of tax money is spent in support of fundamental research, and this is often defended as having an intrinsic virtue. To take the present topic as an example, however, the study of just how molecules adsorb and react on a surface is fascinating and challenging, yet the tax-paying public should not be asked merely to support the esoteric pleasures of a privileged few. The public should expect the occasional major practical advance whose benefits more than pay for the overall cost of all research. The benefits in the present case come from the discovery and development of catalytic processes of major importance to an industrial society. 

Pyrolysis. Pyrolysis of 1,2-dichloroethane in the temperature range of 340—515°C gives vinyl chloride, hydrogen chloride, and traces of acetylene (1,18) and 2-chlorobutadiene. Reaction rate is accelerated by chlorine (19), bromine, bromotrichloromethane, carbon tetrachloride (20), and other free-radical generators. Catalytic dehydrochlorination of 1,2-dichloroethane on activated alumina (3), metal carbonate, and sulfate salts (5) has been reported, and lasers have been used to initiate the cracking reaction, although not at a low enough temperature to show economic benefits. 

Fluid bed reactors became important to the petroleum industry with the development of fluid catalytic cracking (FCC) early in the Second World War. Today FCC is still widely used. The following section surveys the various fluid bed processes and examines the benefits of fluidization. The basic theories of fluidization phenomena are also reviewed. 

Temperature and Humidity When adsorption, absorption, or condensation is employed, the lowest inlet gas temperature is desirable. Adsorbent and absorbent capacities generally increase with the decreasing gas temperature. High waste-gas temperatures may preclude the use of adsorption or condensatit)n due to the cost of chilling. Thermal and catalytic oxidation benefit from a hot effluent gas stream, as that reduces the supplementary fuel requirement. In biological treatment, a waste-gas temperature of near 37 °C is ideal. 

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