Medium oil used for a synthesis reaction, process for preparing dimethyl ether and process for preparing a mixture of dimethyl ether and methanol

Abstract

A medium oil to be used for a synthesis reaction in a slurry-bed reaction procedure. The medium oil has as a main component, a branched, saturated aliphatic hydrocarbon having 16 to 50 carbon atoms, 1 to 7 tertiary carbon atoms, 0 quaternary carbon atoms, and 1 to 16 carbon atoms in the branched chains bonded to the tertiary carbon atoms; and at least one of the tertiary carbon atoms is bonded to hydrocarbon chains with a chain length having 4 or more carbon atoms in three directions.

1 . A medium oil which is used for a synthesis reaction in a slurry-bed reaction procedure comprising, as a main component, a branched, saturated aliphatic hydrocarbon having 16 to 50 carbon atoms, 1 to 7 tertiary carbon atoms, 0 quaternary carbon atoms, and 1 to 16 carbon atoms in the branched chains bonded to the tertiary carbon atoms; and at least one of the tertiary carbon atoms being bonded to hydrocarbon chains with a chain length having 4 more carbon atoms in three directions. 
     
     
         2 . The medium oil according to  claim 1 , wherein the branched, saturated aliphatic hydrocarbon has 20 to 40 carbon atoms and 1 to 4 tertiary carbon atoms. 
     
     
         3 . The medium oil according to  claim 1 , wherein the branched, saturated aliphatic hydrocarbon is represented by formula (I): 
       
         
           
           
               
               
           
         
         wherein R 1 , R 2  and R 4  are independently an n- or iso-alkyl group having 4 to 16 carbon atoms, R 3  is an n- or iso-alkyl group having 1 to 3 carbon atoms, m is an integer of 1 to 7, n is an integer of 0 to 37, and p is an integer of 0 to 12, provided that —(CR 2 H)—, —(CH 2 )— and —(CR 3 H)— are bonded in any order and the total numbers of each unit are m, n and p, respectively. 
       
     
     
         4 . The medium oil according to  claim 1 , wherein the branched, saturated aliphatic hydrocarbon is an α-olefin polymer. 
     
     
         5 . A medium oil which is used for a synthesis reaction in a slurry-bed reaction procedure comprising, as a main component, a branched, saturated aliphatic hydrocarbon which is a dimer to an octamer obtained through polymerization or copolymerization of an α-olefin having 6 to 18 carbon atoms. 
     
     
         6 . The medium oil according to  claims 1  to  5 , which has a pour point of −10° C. or lower. 
     
     
         7 . The medium oil according to  claim 1  or  5 , wherein the synthesis reaction with the slurry-bed reaction procedure comprises producing an oxygen-containing organic compound from a raw gas containing carbon monoxide and hydrogen. 
     
     
         8 . The medium oil according to  claim 7 , wherein the oxygen-containing organic compound is dimethyl ether. 
     
     
         9 . A process for preparing dimethyl ether comprising passing a raw gas containing carbon monoxide and hydrogen through a catalyst slurry containing a mixture comprising (a) the medium oil described in  claim 1  or  5 , (b) a methanol synthesis catalyst, (c) a methanol dehydration catalyst and (d) a methanol shift catalyst or a methanol dehydration/shift catalyst. 
     
     
         10 . A process for preparing a mixture of dimethyl ether and methanol comprising passing a raw gas containing carbon monoxide and hydrogen through a catalyst slurry containing a mixture comprising (a) the medium oil described in  claim 1  or  5 , (b) a methanol synthesis catalyst, (c) a methanol dehydration catalyst and (d) a methanol shift catalyst or a methanol dehydration/shift catalyst.