Process for preparing 2,6-dialkylnaphthalene

Abstract

The present invention relates to a process of preparing dialkylnaphthylenes and polyalkylenenaphthyleneates dialkylnaphthalenes and polyalkylenenaphthalates.

1. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a  naphthalene, monoalkynaphthalene  monoalkylnaphthalene, and dialkylnaphthalene fractions:  
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane  dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 III. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene and recycling the dialkylnaphthalene to step I;  
 IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoaIkylnaphthalene  monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein said monoalkynaphthalene  monoalkylnaphthalene fraction produced in step I is cracked before step III, or in step III, or after step III.  
 
     
     
       2. The process of  claim 1 , wherein at least one of said monoalkylnaphthalene, and isomers of dialkylnaphthalene produced in step IV is recycled in step I. 
     
     
       3. The process of  claim 2 , further comprising cracking of said second dialkylnaphthalene fraction and said naphthalene fractions  fraction before step IV, or in step IV, or after step IV. 
     
     
       4. The process of  claim 1 , wherein at least a portion of said naphthalene fraction in step I is fed to step III to be alkylated with said alkylating agent. 
     
     
       5. The process of  claim 1 , wherein at least step III or step IV is conducted in the presence of a catalyst composition comprising a synthetic zeolite. 
     
     
       6. The process of  claim 5 , wherein the catalyst having a composition comprising a synthetic zeolite is characterized by an X-ray diffraction pattern including interplanar d-spacing (A)
 12.36±0.4  
 11.03±0.2  
 8.83±0.14  
 6.18±0.12  
 6.00±0.10  
 4.06±0.07  
 3.91±0.07  
 3.42±0.06.  
 
     
     
       7. The process of  claim 1 , further comprising (i) separating said dialkylnaphthalene fraction from step I into 2,6-rich-dialkylnaphthalene and 2,6-lean-dialkylnaphthalene fractions, wherein said 2,6-rich-dialkylnaphthalene fraction is utilized in separating and purifying 2,6-dialkylnaphthalene in step II. 
     
     
       8. The process of  claim 7 , further comprising isomerizing said 2,6-lean-dialkylnaphthalene fraction in the presence of a catalyst, wherein the product in said isomerization is fed to step II and/or step I. 
     
     
       9. The process of  claim 8 , further comprising cracking of co-boiler of dialkynaphthalene  dialkylnaphthalene at said 2,6-lean-dialkylnaphthalene stream before isomerization, or with the isomerization, or after isomerization and before step I. 
     
     
       10. The process of  claim 8 , wherein at least a part of the product in said isomerization is separated into a 2,6-rich-dialkylnaphthalene fraction and other components, and said 2,6-rich-dialkylnaphthalene fraction is fed to step II. 
     
     
       11. The process of  claim 8 , wherein the isomerization is conducted in the presence of a catalyst composition comprising a synthetic zeolite. 
     
     
       12. The process of  claim 8 , wherein the catalyst having a composition comprising a synthetic zeolite is characterized by an X-ray diffraction pattern including interplanar d-spacing (A)
 12.36±0.4  
 11.03±0.2  
 8.83±0.14  
 6.18±0.12  
 6.00±0.10  
 4.06±0.07  
 3.91±0.07  
 3.42±0.06.  
 
     
     
       13. The process of  claim 1 , wherein at least a part of the feedstock or at least a part of said monoalkylnaphthalene fraction produced in step I is dealkylated, then recycled to step I. 
     
     
       14. The process of claim  7    10 , wherein at least a part of the other components containing alkylnaphthalene having a higher boiling point than naphthalenes in the separation after the isomerization are dealkylated, then recycled to step I. 
     
     
       15. The process of  claim 1 , wherein a part of said dialkynaphthalene  dialkylnaphthalene fraction after 2,6-dialkylnaphthalene is separated therefrom in step II are dealkylated, then recycled to step I. 
     
     
       16. The process of  claim 1 , wherein separation in step I is conducted by distillation, or distillation and extraction. 
     
     
       17. The process of  claim 1 , wherein 2,6-dialkylnaphthalene is separated by crystallization under high pressure in step II. 
     
     
       18. The process of  claim 1 , wherein said dialkylnaphthalene is dimethylnaphthalene and said monoalkylnaphthalene is monomethylnaphthalene. 
     
     
       19. The process of  claim 1 , wherein said alkylating agent is methanol or dimethylether. 
     
     
       20. A process of preparing a polyethylenenaphthalate polymer or polybutylenenaphthalate polymer comprising; :
 A. oxidizing 2,6-dialkylnaphthalene to form 2,6-naphthalene-dicarboxylic acid; and  
 B. condensing said 2,6-naphthalene-dicarboxylic acid with a diol selected from the group consisting of ethylene glycol and butanediol to form a polyethylenenaphthalate polymer or polybutyrenenaphthalete  polybutylenenaphthalate polymer  
 wherein said 2,6-dialkylnaphthalene is produced by a process comprising the following steps:  
 I. separating a feedstock into a  naphthalene, monoalkynaphthalene  monoalkylnaphthalene, and dialkylnaphthalene fractions: ; 
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane  dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 III. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene;  
 IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein  
 said monoalkynaphthalene  monoalkylnaphthalene fraction produced in step I is cracked before step III, or in step III, or after step III.  
 
     
     
       21. A process for preparing a polyethylene naphthalate polymer or polybutyrenenaphthalate  polybutylenenaphthalate polymer comprising;
 A. oxidizing 2,6-dialkylnaphthalene to form 2,6-naphthalene-dicarboxylic acid; and  
 B. esterifying 2,6-naphthalene-dicarboxylic acid with methanol to form dimethyl-2,6-naphthalene-dicarboxylate; and  
 C. condensing said dimethyl-2,6-naphthalene-dicarboxylate with diol selected from the group consisting of ethylene glycol and butanediol to form a polyethylenenaphthalate polymer or polybutyrenenaphthalate  polybutylenenaphthalate polymer  
 wherein said 2,6-dialkylnaphthalene is produced by a process comprising the following steps:  
 I. separating a feedstock into a  naphthalene, monoalkynaphthalene  monoalkylnaphthalene, and dialkylnaphthalene fractions: ; 
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthlane  dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkynaphthalene fraction;  
 III. alkylating said monoalkylnaphthalene fraction of step I with an alkylating agent to produce dialkylnaphthalene;  
 IV. transalkylating said naphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II, to produce monoalkylnaphthalene, and isomers of dialkylnaphthalene; wherein  
 said monoalkynaphthalene  monoalkylnaphthalene fraction produced in step I is cracked before step III, or in step III, or after step III.  
 
     
     
       22. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a fraction comprising naphthalene and monoalkynaphthalene  monoalkylnaphthalene and a fraction comprising dialkylnaphthalene;  
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkynaphthalene  dialkylnaphthalene fraction;  
 III. dialkylating said naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction of step I and said second dialkylnaphthalene fraction produced in step II;  
 IV. separating a naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction from said dialkylation product of step III;  
 V. alkylating said naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction of step IV; and  
 VI. recycling a product from step V to step I.  
 
     
     
       23. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a fraction comprising naphthalene and monoalkynaphthalene  monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;  
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 IIa. isomerizing said fraction lean in dialkylnaphthalene;  
 IIb. separating the isomerization product of step IIa into a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;  
 IIc. feeding said fraction comprising dialkylnaphthalene of step IIb to step II;  
 III. dialkylating said naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction of step I, said second dialkylnaphthalene fraction produced in step II and a fraction lean in dialkylnaphthalene from step IIb;  
 IV. separating a naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction from said dialkylation of step III;  
 V. alkylating said naphthalene and monoalkynaphthalene  monoalkylnaphthalene fraction of step IV; and  
 VI. recycling a product from step V to step I.  
 
     
     
       24. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene  monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction comprising remaining products;  
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 IIa. dealkylating second dialkylnaphthalene fraction produced in step II and recycling the product of dealkylation to step I;  
 III. dealkylating said fraction comprising remaining products of step I and recycling a product of dealkylation to step I;  
 IV. alkylating said fractions comprising naphthalene and comprising monoalkynaphthalene  monoalkylnaphthalene of step I.  
 
     
     
       25. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene  monoalkylnaphthalene and a fraction comprising dialkylnaphthalene;  
 II. separating said purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 III. dealkylating said second dialkylnaphthalene fraction produced in step II;  
 IIIa. recycling the product of step III to step I; and  
 IV. alkylating said fractions comprising naphthalene and comprising monoalkynaphthalene  monoalkylnaphthalene of step I.  
 
     
     
       26. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock into a fraction comprising naphthalene, a fraction comprising monoalkynaphthalene  monoalkylnaphthalene, a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;  
 II. separating and purifying 2,6-dialkylnaphthalene from said dialkylnaphthalene fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 IIa. isomerizing said fraction lean in dialkylnaphthalene of step I;  
 IIb. separating the isomerization product of step IIa into a fraction comprising dialkylnaphthalene and a fraction lean in dialkylnaphthalene;  
 IIc. recycling a dialkylnaphthalene fraction of step IIb to step II;  
 III. dealkylating said second dialkylnaphthalene fraction produced in step II and a fraction lean in dialkylnaphthalene of step IIb;  
 IV. alkylating said fractions comprising naphthalene and comprising monoalkylnaphthalene of step I; and  
 V. recycling a product from step III to step I.  
 
     
     
       27. A process for producing 2,6-dialkylnaphthalene from a feedstock, comprising the following steps:
 I. separating said feedstock, in distillation towers, into a fraction comprising 2,6-dimethylnaphthalene, a fraction comprising 1,6-dimethylnaphthalene and a fraction comprising a remainder;  
 II. purifying 2,6-dialkylnaphthalene from said 2,6-dimethylnaphthlane   2 , 6 - dimethylnaphthalene  fraction of step I to produce 2,6-dialkylnaphthalene and a second dialkylnaphthalene fraction;  
 IIa. isomerizing said 1,6-dimethylnaphthalene fraction of step I;  
 IIb. separating the isomerization product of step IIa into a fraction comprising 2,6-dimethylnaphthalene and a fraction comprising a remainder;  
 IIc. feeding said fraction comprising 2,6-dimethylnaphthalene of step IIb to step II;  
 III. dealkylating said fraction comprising a remainder of step I, said second dialkylnaphthalene fraction produced in step II, and a fraction comprising a remainder of step IIb;  
 IV. separating a naphthalene and methylnaphthalene fraction from said dealkylation of step III;  
 V. alkylating said naphthalene and methylnaphthalene fraction of step IV; and  
 VI. recycling a product from step V to step I.  
 
     
     
       28. A process for preparing a polyester resin comprising:
   producing  2 , 6   - dialkylnaphthalene from a feedstock by the process of    claim 22   ;        oxidizing the  2 , 6   - dialkylnaphthalene to form  2 , 6   - naphthalenedicarboxylic acid; and        manufacturing the polyester resin from the  2 , 6   - naphthalene - dicarboxylic acid.     
     
     
       29. A process for preparing a polyester resin comprising:
   producing  2 , 6   - dialkylnaphthalene from a feedstock by the process of    claim 22   ;        oxidizing the  2 , 6   - dialkylnaphthalene to form  2 , 6   - naphthalenedicarboxylic acid;        esterifying the  2 , 6   - naphthalenedicarboxylic acid with methanol to form a  2 , 6   - naphthalenedicarboxylate; and        manufacturing the polyester resin from the  2 , 6   - naphthalenedicarboxylate.     
     
     
       30. A process for preparing a polyester resin comprising:
   producing  2 , 6   - dialkylnaphthalene from a feedstock by the process of    claim 24   ;        oxidizing the  2 , 6   - dialkylnaphthalene to form  2 , 6   - naphthalenedicarboxylic acid; and        manufacturing the polyester resin from the  2 , 6   - naphthalene - dicarboxylic acid.     
     
     
       31. A process for preparing a polyester resin comprising:
   producing  2 , 6   - dialkylnaphthalene from a feedstock by the process of    claim 24   ;        oxidizing the  2 , 6   - dialkylnaphthalene to form  2 , 6   - naphthalenedicarboxylic acid;        esterifying the  2 , 6   - naphthalenedicarboxylic acid with methanol to form a  2 , 6   - naphthalenedicarboxylate; and        manufacturing the polyester resin from the  2 , 6   - naphthalenedicarboxylate.