Claims
- 1. A cyclic catalytic lubricant hydro-dewaxing process for treating high-boiling, paraffinic wax-containing liquid petroleum chargestock, said chargestock containing less than 60 wt % aromatics, comprising:
- uniformly distributing and contacting the liquid chargestock in the presence of cofed hydrogen at a pressure of at least 7000 kPa and initial start-of-cycle contact temperature not greater than 315.degree. C. with an acid shape-selective, medium poremetallosilicate hydro-dewaxing catalyst, said catalyst being substantially free of hydrogenation-dehydrogenation components in a reactor having a series of fixed downflow catalyst beds;
- selectively hydrodewaxing paraffinic wax contained in the liquid petroleum in a first serial catalyst bed under adiabatic cracking temperature conditions to partially reduce wax content and thereby producing lighter olefinic components;
- recovering partially dewaxed liquid petroleum and hydrogen-rich gas from a bottom portion of the first serial catalyst bed and redistributing substantially all of said partially hydrodewaxed liquid petroleum and hydrogen-rich gas for contact with said catalyst in at least one downstream fixed catalyst bed;
- further reacting said partially dewaxed liquid petroleum and olefinic component to effect additional endothermic dewaxing, and exothermic hydrogen transfer, olefin oligomerization, hydrogenation and cyclization in the presence of hydrogen under adiabatic temperature conditions, permitting reaction temperature to rise not more than 30.degree. C. in said downstream catalyst bed;
- injecting hydrogen-rich quench gas at the inlet of at least one downstream catalyst bed concurrently with partially hydrodewaxed liquid petroleum to decrease reaction temperature, thereby maintaining a maximum temperature excursion of about 30.degree. C. throughout said series of fixed catalyst beds and controlling uniform hydro-dewaxing conditions to obtain high quality petroleum lubricant product.
- 2. The process of claim 1 wherein said reactor comprises a vertical column containing at least three separate catalyst beds with uniform liquid distribution above each bed, and wherein cold hydrogen quench gas is injected into effluent from an exothermic middle bed.
- 3. The process of claim 1 wherein said liquid petroleum chargestock is high pressure hydrocracked gas oil containing about 1 to 40 wt % mononuclear aromatic hydrocarbons and boiling above about 315.degree. C.
- 4. The process of claim 1 wherein said liquid petroleum chargestock consists essentially of distillate or bright stock.
- 5. The process of claim 1 wherein said catalyst comprises aluminosilicate zeolite having a constraint index of about 2 to 12 and an acid cracking alpha value less than 150.
- 6. The process of claim 5 wherein said catalyst consists essentially of aluminosilicate zeolite having the structure of ZSM-5 and an alpha value of about 45 to 95.
- 7. The process of claim 1 wherein hydrogen partial pressure in said first serial catalyst bed is at least 18,000 kPa, and wherein hydrodewaxing is conducted without substantial net consumption of hydrogen.
- 8. The process of claim 7 wherein said liquid petroleum chargestock comprises hydrocracked gas oil containing about 1 to 40 wt % mononuclear aromatic hydrocarbons and boiling above about 315.degree. C.
- 9. The process of claim 8 wherein said liquid petroleum chargestock consists essentially of distillate or bright stock; and wherein said catalyst comprises aluminosilicate zeolite having a constraint index of about 2 to 12 and an acid cracking alpha value less than 150.
- 10. The process of claim 7 including the step of separating hydrodewaxed reactor effluent to recover a 315.degree. C.+boiling range lubricant product having kinematic viscosity in the range of 10 to 160 cSt. at 40.degree. C.
- 11. A cyclic process for making a lubricant oil of low pour point and improved oxidation stability which comprises:
- (a) catalytically hydro-dewaxing a lubricant range aromatic liquid petroleum chargestock containing paraffin wax in the presence of hydrogen over a dewaxing catalyst comprising medium pore size zeolite in the hydrogen or decationised form during a dewaxing cycle in which the temperature is progressively increased to maintain a substantially constant product pour point to produce a lubricant oil product of improved oxidation stability, the cumulative aging rate of the catalyst being less than 5.degree. F. per day;
- (d) uniformly distributing and contacting the liquid chargestock at initial start-of-cycle reaction temperature of about 200.degree. C. to 315.degree. C. in the presence of cofed hydrogen at partial hydrogen pressure of about 7000 to 20,000 kPa with an acid, shape-selective, medium pore metallosilicate hydro-dewaxing catalyst, said catalyst being substantially free of hydrogenation- dehydrogenation components in a vertical column reactor having a series of fixed downflow catalyst beds;
- (c) selectively hydrodewaxing paraffinic wax contained in the liquid petroleum in a first serial catalyst bed under adiabatic cracking temperature conditions while controlling adiabatic exothermal heat of reaction with a 30.degree. C. maximum excursion from the initial reaction temperature, thereby producing lighter olefinic components;
- (d) recovering partially hydrodewaxed liquid petroleum from a bottom portion of the first serial catalyst bed and redistributing substantially all of said partially hydrodewaxed liquid petroleum for contact with said catalyst in at least one downstream fixed catalyst bed;
- (e) further reacting said partially hydrodewaxed liquid petroleum and olefinic component to effect endothermic hydrodewaxing concurrently with exothermic hydrogen transfer, dewaxing, hydrogenation and cyclization in the presence of hydrogen under adiabatic temperature conditions, permitting net exothermic reaction temperature to rise not more than 30.degree. in said downstream catalyst bed;
- (f) injecting quench fluid into at least one downstream catalyst bed concurrently with partially hydrodewaxed liquid petroleum to decrease reaction temperature, thereby maintaining a maximum temperature excursion of about 30.degree. C. throughout said series of fixed catalyst beds and controlling uniform hydro-dewaxing conditions to obtain high quality petroleum lubricant product; and
- (f) regenerating the catalyst when an end-of-cycle maximum catalyst bed temperature of 375.degree. C. is reached.
- 12. A process according to claim 11 wherein the dewaxing cycle is carried out a temperature not greater than about 315.degree. C.; and where the intermediate pore size zeolite comprises aluminosilicate ZSM-5.
- 13. In the process for making a lubricant oil of low pour point by catalytically dewaxing a wax-containing lubricant boiling range liquid petroleum charge stock in the presence of hydrogen over a hydrodewaxing catalyst containing acid intermediate pore size zeolite in the hydrogen or decationized form, during a dewaxing cycle at controlled temperature to produce a lubricant oil product of improved oxidation stability, the improvement which comprises:
- uniformly distributing and contacting the liquid petroleum chargestock sequentially with cofed hydrogen and byproducts in a cascade multizone reactor having a series of fixed downflow catalyst beds containing the hydro-dewaxing catalyst, said catalyst being substantially free of nickel and other hydrogenation- dehydrogenation components;
- selectively hydrodewaxing paraffinic wax contained in the liquid petroleum in a first serial catalyst bed in the presence of cofed hydrogen under a diabetic cracking temperature conditions, having an initial contact temperature not greater than 315.degree. C., to partially reduce wax content and thereby producing lighter olefinic components;
- recovering partially dewaxed liquid petroleum and hydrogen-rich gas from a bottom portion of the first serial catalyst bed and redistributing said partially hydrodewaxed liquid petroleum, lighter olefinic components and hydrogen-rich gas for contact with said catalyst in at least one downstream fixed catalyst bed;
- further reacting said partially dewaxed liquid petroleum and olefinic component to effect additional endothermic dewaxing, and exothermic hydrogen transfer, olefin oligomerization, hydrogenation and cyclization in the presence of hydrogen under adiabatic temperature conditions, permitting reaction temperature to rise not more than 30.degree. C. in said downstream catalyst bed;
- injecting hydrogen-rich quench gas at the inlet of at least one downstream catalyst bed concurrently with partially hydrodewaxed liquid petroleum, lighter olefinic components and hydrogen-rich gas to decrease reaction temperature, thereby maintaining a maximum temperature excursion of about 30.degree. C. throughout said series of fixed catalyst beds and controlling uniform hydro-dewaxing conditions to obtain high quality petroleum lubricant product; whereby duration of a dewaxing cycle is longer than that of a dewaxing cycle under comparable conditions using a nickel-containing dewaxing catalyst.
- 14. A cyclic catalytic lubricant hydro-dewaxing process for treating high-boiling, paraffinic wax-containing liquid petroleum chargestock during a dewaxing cycle in which the temperature is progressively increased during successive cycles to maintain a substantially constant product pour point to produce a lubricant oil product of improved oxidation stability, the cumulative aging rate of the catalyst being less than 5.degree. F. per day; said chargestock containing high pressure hydrocracked gas oil containing about 1 to 40 wt % mononuclear aromatic hydrocarbons and boiling above about 315.degree. C., comprising:
- uniformly distributing and contacting the liquid chargestock in the presence of cofed hydrogen at a pressure of at least 7000 kPa with an acid, shape-selective, medium pre metallosilicate hydro-dewaxing catalyst, said catalyst being substantially free of hydrogenation-dehydrogenation components in a reactor having a cascade series of fixed downflow catalyst beds;
- selectively hydrodewaxing paraffinic wax contained in the liquid petroleum in a first serial catalyst bed under adiabatic cracking temperature conditions and initial start-of-cycle contact temperature not greater than 315.degree. C. to partially reduce wax content and thereby producing lighter olefinic components, wherein hydrogen partial pressure in said first serial catalyst bed is at least 18,000 kPa, and wherein hydrodewaxing is conducted without substantial net consumption of hydrogen, thereby minimizing reactions other than hydrocracking of paraffinic wax;
- recovering partially dewaxed liquid petroleum and hydrogen-rich gas from a bottom portion f the first serial catalyst bed and redistributing said partially hydrodewaxed liquid petroleum and hydrogen-rich gas for contact with said catalyst in at least one downstream fixed catalyst bed;
- further reacting said partially dewaxed liquid petroleum and olefinic component to effect additional endothermic dewaxing, and exothermic hydrogen transfer, olefin oligomerization, hydrogenation and cyclization in the presence of hydrogen under adiabatic temperature conditions, permitting reaction temperature to rise not more than 30.degree. C. in said downstream catalyst bed;
- injecting hydrogen-rich quench gas at the inlet of at least one downstream catalyst bed concurrently with partially hydrodewaxed liquid petroleum to decrease reaction temperature, thereby maintaining a maximum temperature excursion of about 30.degree. C. throughout said series of fixed catalyst beds and controlling uniform hydro-dewaxing conditions to obtain high quality petroleum lubricant product;
- separating hydrodewaxed reactor effluent to recover a 315.degree. C.+ boiling range lubricant product having kinematic viscosity in the range of 10 to 160 cSt at 40.degree. C.; and
- regenerating the catalyst when an end-of-cycle maximum catalyst bed temperature of 375.degree. C. is reached.
- 15. The process of claim 14 wherein catalyst is regenerated with hot hydrogen.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of co-pending U.S. Pat. application Ser. No. 07/544,088, filed Jun. 27, 1990, now abandoned which is a continuation of U.S. Ser. No. 07/359,605, filed Jun. 1, 1989, now abandoned by T. R. Forbus and C. P. Kyan.
US Referenced Citations (15)
Continuations (1)
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359605 |
Jun 1989 |
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Continuation in Parts (1)
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544088 |
Jun 1990 |
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