Benson process

In die Benson process CH4/Q2 mixtures are heated to 7(X>-17()0 C and rapidly quenched. Ethylene, acetylene and benzene are formed by decomposition of the methyl chloride intermediate. 

Chemical equilibria were calculated for the Benson process (Reaction (17)) using 700/1,200/1,700" C, 2/20/50 atm, and 100/50 molar CH4/CI2 feed. The results are tabulated in Table 4 and major conclusions were ... 

Table 4. Calculated Equilibrium Products of Benson Process CH4 + 1/2 CI2 o HCl, H2, CiHg, C2H4 (Feed CH4/Cl2=100/50 mol)...

Environmental pressures on the process industries will prove to be the most significant change for the next 50 years. Not only will new processes cnange, but mature industries will have to develop new process technology to suiwive (Benson et al., op. dt.). 

Benson and Ponton (1993) and Ponton (1996) have speculated on the ultimate results of continuing efforts for process minimization. They envision a twenty-first century chemical industry totally revolutionized by technological innovation, automation, and miniaturization. Small, distributed manufacturing facilities would produce materials on demand, at the location where they are needed. Raw materials would be nonhazardous, and the manufacturing processes would be waste free and inherently safe. While their vision of future technology is speculative, we are beginning to see progress in this direction. 

Benson, R. S., and J. W. Ponton (1993). "Process Miniaturisation—A Route to Total Environmental Acceptability Trans. IChemE 71, Part A (March), 160-168. 

The last two decades have seen a growing interest in the mechanism of inorganic reactions in solution. Nowhere is this activity more evident than in the topic covered by this review the oxidation-reduction processes of metal complexes. This subject has been reviewed a number of times previously, notably by Taube (1959), Halpern (1961), Sutin (1966), and Sykes (1967). Other articles and books concerned, wholly or partly, with the topic include those by Stranks, Fraser , Strehlow, Reynolds and Lumry , Basolo and Pearson, and Candlin et al ° Important recent articles on the theoretical aspects are those by Marcus and Ruff. Elementary accounts of redox reactions are included in the books by Edwards , Sykes and Benson . The object of the present review is to provide a more detailed survey of the experimental work than has hitherto been available. 

As a possible chemical process for distributed manufacture, the production of toxic feedstock gases is claimed [1,139]. Benson and Ponton were among the first... 

Following a theoretical analysis of distributed small-plant manufacture, Benson and Ponton define assessment criteria for processes suitable for such processing [139]. Since micro reactors are one of the favorite and natural tools for distributed manufacture, this selection list also defines micro-reactor applications. In this context, the authors, probably in one of the first regular citations, emphasize that formulation processes, especially those with multiple ingredients, are particularly suited for distribution. The making of paint on-site is referred to as an already existing way to do so. It stands to reason to augment the scope from formulations to functional chemicals. 

B. Benson and N. Colvin, Plant Practice in the Production of Nickel by Hydrogen Reduction, in Unit Processes in Hydrometallurgy, p. 735, Gordon and Breach, New York, 1964. 

Benfield [Benson and Field] A process for removing carbon dioxide, hydrogen sulfide, and other acid gases from industrial gas streams by scrubbing with hot aqueous potassium carbonate containing activators ... 

Invented by H. E. Benson in 1952 and then developed with J. H. Field at the U.S. Bureau of Mines. First licensed by the Benfield Corporation of Pittsburgh, subsequently acquired by the Union Carbide Corporation, and now licensed by UOP. The current UOP version includes new solution activators and incorporates zeolites or membrane processes for complete separation of acid gases and minimal loss of product gases. More than 650 plants were operating in 1996. Variations include the Benfield HiPure process and the Benfield LoHeat process. See also Carsol, CATACARB, Giammarco-Vetrocoke, HiPure. 

Benson A process for converting methane to ethylene, developed by Hydrocarbon Research, CA. 

HPC [Hot potassium carbonate] A generic name for a process for absorbing acid gases by the use of hot aqueous potassium carbonate. Developed by H. E. Benson and J. H. Field at the U.S. Bureau of Mines in the 1950s. Further developed by other organizations, it became the basis for the Benfield, CATACARB, and other gas purification processes. 

Thus maleic acid forms from the hydroquinone and oxalic acid forms from pyrocatechol. However, the intermediate compounds are triplets, so the intermediate steps are spin-resistant and may not proceed in the manner indicated. The intermediate maleic acid and oxalic acid are experimentally detected in this low-temperature oxidation process. Although many of the intermediates were detected in low-temperature oxidation studies, Benson [59] determined that the ceiling temperature for bridging peroxide molecules formed from aromatics was of the order of 300°C that is, the reverse of reaction (3.128) was favored at higher temperatures. 

Chemical processes, in contrast, are processes that are not limited by rates of energy transfer. In thermal processes, chemical reactions occur under conditions in which the statistical distribution of molecular energies obey the Maxwell-Boltzmann form, i.e., the fraction of species that have an energy E or larger is proportional to e p(—E/RT). In other words, the rates of intermolecular collisions are rapid enough that all the species become thermalized with respect to the bulk gas mixture (Golden and Larson, 1984 Benson, 1976). 

Isomerizations are important unimolecular reactions that result in the intramolecular rearrangement of atoms, and their rate parameters are of the same order of magnitude as other unimolecular reactions. Consequently, they can have significant impact on product distributions in high-temperature processes. A large number of different types of isomerization reactions seem to be possible, in which stable as well as radical species serve as reactants (Benson, 1976). Unfortunately, with the exception of cis-trans isomerizations, accurate kinetic information is scarce for many of these reactions. This is, in part, caused by experimental difficulties associated with the detection of isomers and with the presence of parallel reactions. However, with computational quantum mechanics theoretical estimations of barrier heights in isomerizations are now possible. 

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