Reduction of hydrocarbons

This reaction has been used to make crystalline triphenylmethyl derivatives that have been characterized by X-ray structure determinations,22 and a technique has been developed for the reduction of hydrocarbons by liquid cesium activated by ultrasound irradiation in the presence of ethers such as diglyme.23 The blue solutions obtained when cesium metal is dissolved in THF in the presence of [18]-crown-6 have been used to metallate a series of 1,4- or 1,5-hexadienes. The organocesium compounds have not been isolated but they have been identified by derivatization by carbonation and trimethylsilylation.24 Substituted cyclopentadienyl derivatives of sodium have also been synthesized by this method.25... 

Entropies for the reduction of hydrocarbons and radical cations in acetonitrile... 

Thermocatalytic sulfate reduction probably is the main source of H2S in the deep subsurface (25.81). The reactions in Table II, based on the evolution of H2S and CO2 by sulfate reduction of hydrocarbons in clastic sequences where there is available SO42- (i.e. sequences with evaporite beds or cements), illustrate the importance of this process to diagenesis. Not only does it provide a diagenetic sink for Fe via pyrite, but depending on the relative availability of reactants, can either cause precipitation or dissolution of calcite and alter feldspars to clay minerals. 

Figure 4. Chemical divide model for sulfate reduction of hydrocarbons, and their effect on diagenetic reactions. Numbers refer to reactions in Table II (based on 3, 25, 81).

Back where it all began, the increasing vehicle population and the increasing frequency of red-eye days led the California Legislature in 1959 to require the State Department of Public Health to develop and publish standards for the quality of air and for vehicle exhaust emissions before February 1, 1960 (14). These standards, which were adopted on December 4, 1959, were based on the judgement that in order to achieve desirable air quality standards, 80% reduction of hydrocarbon (HC) and 60% reduction of carbon monoxide (CO) emissions were needed. In terms of the test cycle which was also established, the standards were 275 ppm (volume) of hydrocarbons as hexane (or 0.165% as C] ) and 1.5% (volume) of CO. 

Most western countries have legislated reductions of hydrocarbon emissions. In SX plants, this means a tendency away from the use of aromatic components. In Africa, Australia, and South America, diluents containing 20 to 25% aromatic contents are still common, while in North America, diluents seldom contain more than 5% aromatics. Some processes, however, require 100% aromatic diluents because of their solvation properties. The uranium and precious metals industries often employ aromatic diluents, while cobalt, nickel, and zinc systems can anploy 100% aliphatic diluents. 

PHYSICAL AND CHEMICAL PROPERTIES OXIDATION AND REDUCTION OF HYDROCARBONS... 

While reactions of the unsaturated systems will be discussed subsequently, quantitative evaluation of the results of oxidation and reduction of hydrocarbons provides the basis for much that follows. 

F have been used in this process. A modification of the process resulting in an appreciable reduction of hydrocarbon gas loss has been described by Freireich and Tennyson (1977). In this scheme, the gas from the second intermediate pressure flash is washed with. solvent in a small absorber. The overhead from this absorber is recompressed and recycled to the plant inlet. It is claimed that the value of the recovered gas amply compensates for the cost of the additional equipment, and that a payout as low as three months is realized with a fuel cost of 2 per MMbtu. 

Shi, Y., Ge, H.W., Brakora, J.L., Reitz, R.D. Automatic chemistry mechanism reduction of hydrocarbon fuels for HCCI engines based on DRGEP and PCA methods with error control. Energy Fuels 24, 1646-1654 (2010a)... 

These considerations are valid not only with respect to the electrolytic reduction of hydrocarbons [42, 43], but also to quinones [44-48], carbonyl compounds [49], nitro compounds [22, 24, 31, 50], and other classes of organic depolarizers. Hence the need... 

---