Process for catalytic upgrading light petroleum hydrocarbons accompanied by low temperature regenerating the catalyst

Abstract

This invention relates to a process for catalytically upgrading light petroleum hydrocarbons accompanied by low temperature regenerating the catalyst, which comprises injecting the light petroleum hydrocarbons into a catalytic cracking reactor, contacting the light petroleum hydrocarbons with a regenerated catalyst and carrying out the reaction, separating the reaction products regenerating the stripped catalyst for 10 to 50 minutes under the regeneration conditions of a temperature of 400 to 600° C. and a pressure of 0.1 to 0.6Mpa; recycling the regenerated catalyst into the reactor. The process of the present invention can reduce the olefin content of gasoline, increase the cetane number of diesel oils, and decrease the contents of sulfur and nitrogen to some extent.

We claim:  
     
         1 . A process for catalytically upgrading light petroleum hydrocarbons accompanied by low temperature regenerating the catalyst, characterized in that: 
 a) introducing the light petroleum hydrocarbons and the regenerated catalyst into a reactor to form a mixture of the feedstock and the catalyst;    b) catalytically converting the light petroleum hydrocarbon under the conditions of a temperature 200 to 450° C. a pressure of 0.1 -0.5 Mpa, a catalyst-oil ratio of 2 to 15 and a reaction time of 1 to 20 second to form a mixture of the resultant including gasoline, diesel oil and liquefied gas, and the spent catalyst;    c) separating the resultant and the spent catalyst;    d) stripping the spent catalyst;    e) regenerating the stripped spent catalyst for 10 to 50 minutes under a temperature of 400 to 600° C. and a pressure of 0.1 to 0.6 Mpa;    f) feeding the regenerated catalyst back to the reactor for reuse through circulation.    
     
     
         2 . A process according to  claim 1 , characterized in that said light petroleum hydrocarbon is selected from a primary processing distillate oil, a secondary processing distillate oil and their mixture, and the light petroleum hydrocarbon has a distillation range from an initial boiling point to 400° C. in accordance with Engler distillation.  
     
     
         3 . A process according to  claim 1 , characterized in that said light petroleum hydrocarbon is selected from one distillation cut or mixture consisting of more than one distillation cut comprising straight-run gasoline, straight-run diesel oil, coking gasoline, coking diesel oil, cracking gasoline, cracking light cycle oil, hydrogasoline or hydrogenation diesel oil.  
     
     
         4 . A process according to  claim 1 , characterized in that the process is suitable for fluidized bed reactor, riser reactor, down-flow type reactor and any modified units based on the conventional catalytic. Cracking unit.  
     
     
         5 . A process according to  claim 1 , characterized in that said reaction conditions for catalytically upgrading light petroleum hydrocarbons comprise: a reaction temperature of 200 to 400° C., a catalyst-oil ratio of 3 to 10, a reaction time of 2 to 10 second, a reaction pressure of 0.15 to 0.4 Mpa, a weight ratio of atomization steam to the light petroleum hydrocarbon of 0.01 to 0.2.  
     
     
         6 . A process according to  claim 1 , characterized in that said stripped spent catalyst is regenerated under the following conditions: a regeneration temperature of 450 to 550° C., a regeneration time of 10 to 30 minutes and a regeneration pressure of 0.15 to 0.45 Mpa, the content of the excess oxygen in the regeneration flue gas is less than 5% volume, and the carbon content of regenerated catalyst is less than 0.7% by weight.  
     
     
         7 . A process according to  claim 6 , characterized in that the content of the excess oxygen in the regeneration flue gas is less than 1% volume, and the carbon content of the regenerated catalyst is less than 0.5% by weight.  
     
     
         8 . A process according to  claim 1 , characterized in that said catalyst contains high silicon zeolite with pentasil structure.  
     
     
         9 . A process according to  claim 1 , characterized in that said regenerated catalyst is cooled in part or all in a cooler and then fed back to the reactor for reuse through circulation.  
     
     
         10 . A process according to  claim 1 , characterized in that the overheated steam is used as a stripping medium during said stripping of catalyst, or a part of the regenerated catalyst can also be introduced to the stripper and mixed with the spent catalyst.