C₆ Pure hydrocarbon-air-steam reaction at high temperature has been studied by using two types of catalysts both containing 5% NiO. The hydrocarbons used were n-hexane, cyclohexane, and benzene.
The amount of gas produced and conversion in this reaction were better than that of hydrocarbon-steam and hydrocarbon-air reaction. In the hydrocarbon-air-steam reaction it was better to use catalyst which was prepared for gaseous hydrocarbon than that for heavy hydrocarbon. Good results were obtained when contact temperature was above 850°C and LHSV for feed oil was less than 1. It was also found that there was a relation between the volume of gas produced and steam/air ratio.
The order of reactivity of the hydrocarbons used was n-hexane>cyclohexane>benzene. The free energy change and reaction heat for these reactions were calculated and the experimental results are discussed. The results of experiments were in good accord with the theoretical considerations.

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Arabian crude oil containing 1.69wt% of sulfur was hydrodesulfurized under moderate conditions with various kinds of hydrogenation catalyst.
The catalyst performance and the effect of operating conditions were investigated. Analysis and evaluation of the treated oil were also made in comparison with the feed stock.
Catalysts of various composition were prepared by impregnation or mixing. The physical properties of the catalyst such as surface area and pore diameter and the preparation method had little effect on the catalyst performance, whereas the metal composition of the catalyst exerted a great influence on the performance. The Co-Mo catalyst with a small amount of Ni added, proved to exhibit the best activity, longest life and easiest regeneration. The vanadium-containing catalyst, on the other hand, was found to be difficult to regenerate, and upon repeated regenerations its activity gradually decreased.
The crude oil was upgraded through the hydrodesulfurization process as follows under the typical conditions, i. e. 420°C, 40kg/cm², 2vol/vol/hr and H₂/HC mole ratio of 6-7. The sulfur content was reduced from 1.69wt% to 0.74wt%, and the gravity increased from 33.8 API to 38.6 API. The Conradson carbon, ash and viscosity substantially decreased. The yield of the topped crude (125c.s. @ 50°C) was considerably reduced from 48% to 24% on crude, while the yield of distillates, particularly of gas oil, increased.
Generally speaking, dehydrogenation reaction was slightly dominant over hydrogenation reaction as seen from a slight drop in the H/C ratio.
The olefins and aromatics in the naphtha fraction increased a little, and thus the octane number and lead susceptibility improved. However, quite unexpectedly, the sulfur content in light naphtha increased, resulting in a lower lead susceptibility. It was difficult to decrease sulfur in light naphtha, especially under severe operating conditions such as high temperatures and low LHSV's. The sulfur in heavy naphtha was removed by 45%, and it is very suitable for reforming feed stock. Kerosine and gas oil can be made products marketable without further treating. Sulfur in the residua was lowered below 1.5wt%, thus meeting the low sulfur fuel oil quality requirement.

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The addition reaction of isoprene and sulfur dioxide in n-heptane solution was studied kinetically in liquid phase. It was observed that the rate of reaction was of the second-order with activation energy of 11kcal/mol and an entropy factor of 8×10⁵ (1/mol, hr.).
Upon investigating the equilibrium constant at temperatures ranging from 100°C to 140°C, the heat of reaction was calculated to be -20kcal/mol, showing that the reaction was exothermic.
On observing the thermal dissociation rate of the addition product, i. e. monosulfone, its half-life was determined to be 3hr. at 120°C, 30min. at 140°C, and less than 2min. at 200°C. It was also confirmed that pure isoprene could be separated easily quantitatively from the dissociation products.

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