Method for producing aromatic hydrocarbons

Abstract

Disclosed is a method for producing aromatic hydrocarbons including a cracking reforming reaction step of bringing a feedstock having a 10 vol % distillation temperature of 140° C. or higher and a 90 vol % distillation temperature of 380° C. or lower, into contact with a catalyst for monocyclic aromatic hydrocarbon production containing a crystalline aluminosilicate to cause the feedstock to react with the catalyst, and thereby obtaining a product including monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers and a heavy oil fraction having 9 or more carbon numbers; a step of separating the monocyclic aromatic hydrocarbons and the heavy oil fraction from the product obtained from the cracking reforming reaction step; a step of purifying the monocyclic aromatic hydrocarbons separated in the separating step, and collecting the hydrocarbons; and a step of separating naphthalene compounds from the heavy oil fraction separated in the separating step, and collecting the naphthalene compounds.

1 . A method for producing aromatic hydrocarbons, the method comprising the steps of:
 bringing a feedstock having a 10 vol % distillation temperature of 140° C. or higher and a 90 vol % distillation temperature of 380° C. or lower, into contact with a catalyst for monocyclic aromatic hydrocarbon production containing a crystalline aluminosilicate to cause the feedstock to react with the catalyst, and thereby obtaining a product including monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers and a heavy oil fraction having 9 or more carbon numbers;   separating respectively the monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers and the heavy oil fraction having 9 or more carbon numbers from the product obtained from the cracking reforming reaction step;   purifying the monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers thus separated in the separation step, and collecting the monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers; and   separating naphthalene compounds that include at least naphthalene, from the heavy oil fraction having 9 or more carbon numbers thus separated in the separation step, and collecting the naphthalene compounds.   
     
     
         2 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein the step of collecting naphthalene is a process of separating and collecting methylnaphthalene and/or dimethylnaphthalene, and naphthalene. 
     
     
         3 . The method for producing aromatic hydrocarbons according to  claim 1 , further comprising the steps of:
 hydrogenating a remaining fraction obtained by separating naphthalene compounds in the step of collecting naphthalene, and obtaining a hydrogenation reaction product; and   recycling the hydrogenation reaction product to the step of cracking reforming reaction.   
     
     
         4 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein in the step of collecting naphthalene, the apparatus for separating and collecting naphthalene compounds including naphthalene is a distillation apparatus. 
     
     
         5 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein the crystalline aluminosilicate comprises a zeolite with medium-sized pores and/or a zeolite with large-sized pores as main components. 
     
     
         6 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein the reaction temperature employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the step of cracking reforming reaction is from 400° C. to 650° C. 
     
     
         7 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein the reaction pressure employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the step of cracking reforming reaction is from 0.1 MPaG to 1.5 MPaG. 
     
     
         8 . The method for producing aromatic hydrocarbons according to  claim 1 , wherein the contact time for bringing the feedstock into contact with the catalyst for monocyclic aromatic hydrocarbon production in the step of cracking reforming reaction is from 1 second to 300 seconds.