Processes for dehydrogenation of a hydrocarbon feedstock are described. The process can be run at lower H.sub.2/HC ratios and lower RITs while maintaining coke production at the same level as operation at higher H.sub.2/HC ratios and higher RITs without decreasing the yield per pass. Acceptable levels of coke were achieved when operating the process at low hydrogen to hydrocarbon molar ratio in the range of 0.01 to 0.40 and reactor inlet temperatures in the range of 500?-645? C.

Processes for dehydrogenation of a hydrocarbon feedstock are described. The process can be run at lower H.sub.2/HC ratios and lower RITs while maintaining coke production at the same level as operation at higher H.sub.2/HC ratios and higher RITs without decreasing the yield per pass. Acceptable levels of coke were achieved when operating the process at low hydrogen to hydrocarbon molar ratio in the range of 0.01 to 0.40 and reactor inlet temperatures in the range of 500?-645? C. The process uses a low coke catalyst.

Large pill dehydrogenation catalysts and large screens slot width are combined in dehydrogenation units to reduce the pressure drop across the catalyst bed and reactor screens compared to conventional screen and catalyst size combinations. The catalyst has an average pill diameter in the range of 1.6 mm to 3.0 mm, and the slot width of the screen is in the range of about 30% to about 60% of the pill diameter.

Disclosed are a method and a system for producing bio-derived aromatic hydrocarbons from a renewable resource. More particularly, the disclosure provides for the co-location of a biomass reactor unit and an aromatization reactor unit to produce benzene from a renewable source such as plant mass. Hexane produced from cellulose in the biomass reactor unit can be converted to benzene in the aromatization reactor unit and hydrogen produced in the aromatization reactor unit can be used in the biomass reactor unit. Also described is the use of a mixture of bio-derived hexane produced from cellulose and naphtha in an aromatization process.

The present invention relates to energy saving method and apparatus for preparing styrene and alpha-methylstyrene concurrently, by which economic feasibility may be improved by reusing energy during preparing styrene and alpha-methylstyrene concurrently.

A process for producing phenylstyrene comprises contacting benzene with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation product comprising cyclohexylbenzene. At least part of the cyclohexylbenzene is then contacted with ethylbenzene in the presence of a transalkylation catalyst under conditions effective to produce a transalkylation product comprising cyclohexylethylbenzene and/or with ethylene in the presence of an alkylation catalyst under conditions effective to produce an alkylation product comprising cyclohexylethylbenzene. At least part of the cyclohexylethylbenzene is then contacted with a dehydrogenation catalyst under conditions effective to produce a dehydrogenation product comprising phenylstyrene.

A system for making cyclohexylbenzene starting from benzene and hydrogen includes a first benzene preparation column, a hydroalkylation reactor, a dehydrogenation reactor, a second distillation column for cyclohexylbenzene separation, a third distillation column for cyclohexylbenzene purification, a transalkylation reactor, and a fourth distillation column for separating cyclohexylbenzene from transalkylation effluent. All components are integrated to achieve a high-purity cyclohexylbenzene product produced with a high yield and high overall energy efficiency.

The present invention is related to the isomerization process in which a light naphtha stream comprising of paraffinic (mono and single branched), naphthenic and aromatic hydrocarbons in the range of C.sub.5-C.sub.7 is contacted with the solid catalyst in multiple reaction zones and in presence of hydrogen to produce high octane gasoline predominantly comprising of paraffins (single and di-branched) and naphthenes. The process scheme comprises of more than one isomerization reaction section operating at different temperatures and other operating conditions. The catalyst employed in these reaction sections is a high coordination sulfated mixed metal oxide catalyst which contains at least one noble metal and sulfated zirconia in addition to the other components. The process of the present invention also comprises more than one fractionation section and recycling of a particular stream to the reaction zone for improving the isomerization of light naphtha.