Summary:Hydrodecyclization reaction of methylcyclopentane (MCP) and benzene was studied under the conditions close to commercial reforming processes, and in the presence of a platinum-alumina reforming catalyst poisoned by coke and/or thiophene or activated by chloride.Decyclization reaction of MCP takes place competitively on two different kinds of active site. One of them is highly active, but is easily poisoned by small amount of thiophene added to the feed or moderate amount of coke deposited on the catalyst, while the other one is relatively less active, but is little affected by those poisons.The former would be on the surface of platinum, and the latter is perhaps acid sites of the alumina carrier.The rate of hydrodecyclization of MCP-including small amount of hydrocracking-, which was catalyzed by each site mentioned above was nearly of first order with respect to the partial pressure of MCP. And the rate of isomerization of MCP to six-membered ring compounds was also observed to be of first order with respect to the partial pressure of MCP.From the experiment of chloride activation, it seems that decyclization reaction of MCP can take place on. relatively weak acid sites, while isomerization to six-membered ring takes place only on relatively strong acid sites.According to the kinetic discussion on hydrodecyclization of MCP and benzene, it is concluded that the rate constant of cyclization of n-hexane to MCP is higher than that of n-hexane to six-membered ring, and the rate constant of MCP to six-membered ring is much higher than that of n-hexane to MCP, under the conditions close to commercial reforming processes, using the catalyst moderately poisoned by coke and sulfur compounds.
Summary:Experiments were carried out on the reactions of four heptane isomers, four octane and 60kg/cm2 hydrogen pressure, in order to have a better understanding of the reactions. Reaction products were analyzed by means of a gas chromatographic unit. Reaction rate and selectivity were studied at low conversion levels with the following results:(1) Paraffinic hydrocarbons with higher number of branches were converted faster than did those with lower number of branches;(2) Isomerization reaction of a paraffin molecule to others with the same number of branches were very fast;(3) Hydrocracking reactions were very slow compared with isomerization reactions except for trimethylpentanes;(4) Decyclization reactions of methylcyclopentane and methylcyclohexane were very slow. Discussed were the reaction path and mechanism, and it was suggested that tertiary carbonium ions are more reactive than secondary ones and far more reactive than primary carbonium ions because of the higher rate of adsorption of olefins to form tertiary carbonium ions, the higher concentration of tertiary carbonium ions on acidic sites, and the higher rate of desorption of the tertiary carbonium ions.
Summary: For the production of ML-grade motor oil, mildly solvent extracted and dewaxed motor oil fractions, obtained from Persian Gulf crude, were hydrogen-treated with CoMo (sulfide)/alumina catalyst under various treating conditions. A bench-scale pilot plant containing 200ml of the catalyst was used for the hydrogen-treatment. General properties, oxidation stability and engine performance of the hydrogen-treated oils were compared with those of acid/clay-treated oils.Hydrogen-treated oils obtained under relatively severe treating conditions showed favorable properties in color and viscosity index. They showed, however, inferior oxidation stability and poor engine performance, and also their viscosity was decreased.On the other hand, hydrogen-treated oils obtained under relatively mild treating conditions showed good oxidation stability and good engine performance. General properties, oxidation stability and engine performance of these oils were almost the same with those of acid/clay-treated oils.
Paraffinic distillate lubricating oil fractions-a spindle oil fraction, a machine oil fraction, a solvent-extracted turbine oil fraction, and two kinds of solvent-extracted motor oil fractions different in the severities of solvent extraction-from Persian Gulf crude were hydrogen-treated, over a CoMo-sulfide/alumina catalyst, under hydrogen pressures. Bench-scale pilot plants were used for the hydrogen-treatment. Hydrogen-treated lubricating oils having favorable general propertiese. g., color, viscosity index, aniline point, sulfur content, and nitrogen content-were obtained by the treatment under relatively severe conditions. General properties of these oils were better than those of acid/clay-treated oils. Under the severe treating conditions, however, viscosity of the hydrgentreated oils was slightly reduced, and their oxidation stability was decreased. On the other hand, hydrogen-treated oils having good oxidation stability were obtained by the treatment under relatively mild conditions. The oxidation stability of these oils was almost the same with that of acid/claytreated oils. And the general properties of the product oils obtained by these mild hydrogen-treatment were also almost equal to those of acid/clay-treated oils.
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