The present invention describes a process for the production of high-purity paraxylene from a xylenes cut containing xylenes and ethylbenzene, a process using two simulated moving bed separation units and two isomerization units.

The present invention describes a process for the production of high-purity paraxylene from a xylenes cut containing xylenes and ethylbenzene, a process using two simulated moving bed separation units and two isomerization units.

The present invention describes a process for the production of high-purity paraxylene based on a xylene cut, a process using one simulated mobile bed separation unit and two isomerization units, one in gas phase and the other in liquid phase.

The present invention describes a process for the production of high-purity paraxylene based on a xylene cut, a process using one simulated mobile bed separation unit and two isomerization units, one in gas phase and the other in liquid phase.

Disclosed herein is an activated EU-2 zeolite, including: pores having a diameter of 30 to 40 while maintaining the crystal structure of the EU-2 zeolite; and pores having a diameter of 40 to 200 , wherein the volume of the pores having a diameter of 30 to 40 is 0.01 to 0.06 cc/g, and the volume of the pores having a diameter of 40 to 200 is 0.07 to 0.4 cc/g.

A method for producing a lubricant base oil which comprises a first step of carrying out isomerization dewaxing by contacting, in the presence of hydrogen, a hydrocarbon oil containing normal paraffin having a boiling point of 360 C. or higher, with a hydroisomerization catalyst under conditions such that a cracking rate defined in the following formula (1) is 10 mass % or less, and a second step of carrying out the above isomerization dewaxing by temporarily switching the above conditions to conditions such that the cracking rate is 13 mass % or more.
Cracking rate (mass %)=[(C.sub.1C.sub.2)/C.sub.1]100(1)
wherein C.sub.1 represents the mass ratio of a fraction having a boiling point of 360 C. or higher in the above hydrocarbon oil, and C.sub.2 represents the mass ratio of the fraction having a boiling point of 360 C. or higher in the above hydrocarbon oil after the isomerization dewaxing.

The invention relates to a process for the manufacture of diesel range hydrocarbons wherein a feed is hydrotreated in a hydrotreating step and isomerised in an isomerisation step, and a feed comprising fresh feed containing more than 5 wt % of free fatty acids and at least one diluting agent is hydrotreated at a reaction temperature of 200-400 C., in a hydrotreating reactor in the presence of catalyst, and the ratio of the diluting agent/fresh feed is 5-30:1.

The present invention provides a modified composite molecular sieve, and a preparation method and an application of the modified composite molecular sieve. The modified composite molecular sieve comprises SiO.sub.2 and a composite molecular sieve that comprises molecular sieve MCM-22 and zeolite A selected from at least one of ZSM-22, ZSM-23 and ZSM-48, wherein, the molecular sieve MCM-22 covers around the zeolite A. The present invention further provides a catalyst and an application of the catalyst. The catalyst comprises a carrier and a noble metal loaded on the carrier, wherein, the carrier comprises a modified composite molecular sieve that is the modified composite molecular sieve provided in the present invention or the modified composite molecular sieve obtained with the method provided in the present invention. The catalyst that utilizes the composite molecular sieve as a carrier not only can decrease the solidifying point of waxy raw oil, but also can improve the yield of liquid product, is especially applicable to the isomerization dewaxing process of lube distillate, and has an advantage of remarkably improving the viscosity index of lube base oil.

The hydroisomerization catalyst of the present invention is a catalyst used for hydroisomerization of a hydrocarbon, including a support including a calcined zeolite modified with at least one metal selected from the group consisting of Na, K, Cs, Mg, Ca, Ba, and K, and having a thermal history that includes heating at 350 C. or more, and at least one inorganic oxide selected from the group consisting of alumina, silica, titania, boria, zirconia, magnesia, ceria, zinc oxide, phosphorus oxide, and a composite oxide containing a combination of at least two or more of these oxides; and at least one metal supported on the support and selected from the group consisting of elements belonging to Groups 8 to 10 of the periodic table, molybdenum and tungsten.

A process and catalyst system is disclosed for producing para-xylene from a C.sub.8 hydrocarbon mixture comprising ethylbenzene and at least one xylene isomer other than para-xylene. The process modifies the conventional process by operating with a higher weight hourly space velocity, lower pressure and lower hydrogen partial pressure, which allows production of on-specification benzene product without penalty with respect to ethylbenzene conversion, para-xylene approach to equilibrium or xylene losses. The catalyst system comprises a first catalyst bed comprising a first zeolite having a constraint index from 1 to 12 and an average crystal size from 0.1 to 1 micron and a platinum hydrogenation component, and a second catalyst bed comprising a second zeolite having a constraint index ranging from 1 to 12 and an average crystal size of less than 0.1 micron and a rhenium hydrogenation component.