Process for converting oxygenates to olefins using molecular sieve catalysts comprising desirable carbonaceous deposits

Abstract

The present invention relates to methods for selectively converting oxygenates to light olefins, preferably ethylene and propylene, in which desirable carbonaceous deposits are maintained on a total reaction volume of catalyst by totally regenerating only a portion of the total reaction volume of catalyst and mixing the regenerated portion with the unregenerated total reaction volume of catalyst.

We claim:  
     
         1 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulation of undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         2 . The method of  claim 1  wherein said regenerated amount of carbonaceous deposits comprises an amount of about 0.5 wt % or less of said regenerated portion.  
     
     
         3 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulation of greater than about 1.5 wt % carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective form a regenerated portion comprising in the range of from about 0 wt % to about 0.5 wt % carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder) wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         4 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulation of greater than about 1.5 wt % carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to form a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprise an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         5 . The method of  claim 1  wherein said desirable carbonaceous deposits comprise an amount in the range of from about 2 wt % to about 30 wt % of said total reaction volume of molecular sieve catalyst.  
     
     
         6 . The method of  claim 2  wherein said desirable carbonaceous deposits comprise an amount in the range of from about 2 wt % to about 30 wt % of said total reaction volume of molecular sieve catalyst.  
     
     
         7 . The method of  claim 3  wherein said desirable carbonaceous deposits comprise an amount in the range of from about 2 wt % to about 30 wt % of said total reaction volume of molecular sieve catalyst.  
     
     
         8 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %; and,    wherein, upon accumulation of greater than about 1.5 wt/a carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective form a regenerated portion comprising in the range of from about 0 wt % to about 0.5 wt % carbonaceous deposits; and,  
   mixing said regenerated portion with said remainder to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %.    
     
     
         9 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst under conditions effective to produce a stream comprising light olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to light olefins than in the absence of said desirable carbonaceous deposits, and wherein said molecular sieve catalyst is selected from the group consisting of: 
 zeolites having a structural type selected from the group consisting of AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, and combinations thereof; and,  
 silicoaluminophosphate catalysts (SAPO's) selected from the group consisting of SAPO-34, SAPO-17, SAPO-18, substituted SAPO's comprising MeAPSO's, and combinations thereof; and,  
   wherein, upon accumulation of undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         10 . The method of  claim 2  wherein said molecular sieve catalyst is selected from the group consisting of: 
 zeolites having a structural type selected from the group consisting of AEL AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, and combinations thereof; and,  
 silicoaluminophosphate catalysts (SAPO's) selected from the group consisting of SAPO-34, SAPO-17, SAPO-18, substituted SAPO's comprising MeAPSO's, and combinations thereof.  
 
     
     
         11 . The method of  claim 3  wherein said molecular sieve catalyst is selected from the group consisting of: 
 zeolites having a structural type selected from the group consisting of AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, and combinations thereof; and,  
 silicoaluminophosphate catalysts (SAPO's) selected from the group consisting of SAPO-34, SAPO-17, SAPO-18, substituted SAPO's comprising MeAPSO's, and combinations thereof.  
 
     
     
         12 . The method of  claim 4  wherein said molecular sieve catalyst is selected from the group consisting of: 
 zeolites having a structural type selected from the group consisting of AEI, AFT, APC, ATN, ATT, ATV, AWW, BIK, CAS, CHA, CHI, DAC, DDR, EDI, ERI, GOO, KFI, LEV, LOV, LTA, MON, PAU, PHI, RHO, ROG, THO, MFI, MEL, MTW, EUO, MTT, HEU, FER, AFO, AEL, TON, and combinations thereof; and,  
 silicoaluminophosphate catalysts (SAPO's) selected from the group consisting of SAPO-34, SAPO-17, SAPO-18, substituted SAPO's comprising MeAPSO's, and combinations thereof.  
 
     
     
         13 . The method of  claim 1  wherein said molecular sieve catalyst is selected from the group consisting of ZSM-5, ZSM-34, erionite, chabazite, and SAPO-34.  
     
     
         14 . The method of  claim 2  wherein said molecular sieve catalyst is selected from the group consisting of ZSM-5, ZSM-34, erionite, chabazite, and SAPO-34.  
     
     
         15 . The method of  claim 3  wherein said molecular sieve catalyst is selected from the group consisting of ZSM-5, ZSM-34, erionite, chabazite, and SAPO-34.  
     
     
         16 . The method of  claim 4  wherein said molecular sieve catalyst is selected from the group consisting of ZSM-5, ZSM-34, erionite, chabazite and SAPO-34.  
     
     
         17 . The method of  claim 1  wherein said molecular sieve catalyst is selected from the group consisting of small pore and medium pore molecular sieve catalysts.  
     
     
         18 . The method of  claim 2  wherein said molecular sieve catalyst is selected from the group consisting of small pore and medium pore molecular sieve catalysts.  
     
     
         19 . The method of  claim 3  wherein said molecular sieve catalyst is selected from the group consisting of small pore and medium pore molecular sieve catalysts.  
     
     
         20 . The method of  claim 4  wherein said molecular sieve catalyst is selected from the group consisting of small pore and medium pore molecular sieve catalysts.  
     
     
         21 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst other than ZSM-5 under conditions effective to produce a stream comprising light olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to light olefins than in the absence of said desirable carbonaceous deposits; and,    wherein upon accumulation of undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         22 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-34 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulation of undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         23 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-34 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %; and,    wherein, upon accumulating greater than about 1.5 wt % carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective form a regenerated portion comprising in the range of from about 0 wt % to about 0.5 wt % carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %.  
   
     
     
         24 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-17 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulating undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         25 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-17 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %; and,    wherein, upon accumulation of greater than about 1.5 wt % carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective form a regenerated portion comprising in the range of from about 0 wt % to about 0.5 wt % carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %.  
   
     
     
         26 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-18 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits which render said catalyst more selective to C 2 -C 3  olefins than in the absence of said desirable carbonaceous deposits; and,    wherein, upon accumulation of undesirable carbonaceous deposits effective to interfere with catalyst activity, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective to remove said undesirable carbonaceous deposits, forming a regenerated portion comprising in the range of from about 0 wt % to a regenerated amount of carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder, wherein said regenerated amount of carbonaceous deposits comprises an amount sufficient, upon said mixing, to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits.  
   
     
     
         27 . A method for treating a molecular sieve catalyst comprising: 
 contacting a feed comprising oxygenates with a total reaction volume of a molecular sieve catalyst comprising SAPO-18 under conditions effective to produce a stream comprising C 2 -C 3  olefins, wherein said total reaction volume comprises desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %; and,    wherein, upon accumulating greater than about 1.5 we/o carbonaceous deposits, said desirable carbonaceous deposits are maintained on said molecular sieve catalyst by a process comprising: 
 separating said total reaction volume of molecular sieve catalyst into a portion and a remainder;  
 treating said portion with a regeneration medium under conditions effective form a regenerated portion comprising in the range of from about 0 wt % to about 0.5 wt % carbonaceous deposits; and,  
 mixing said regenerated portion with said remainder to produce a regenerated total reaction volume comprising said desirable carbonaceous deposits in the range of from about 2 wt % to about 30 wt %.