| abstract |
A method for producing a 3,4' and/or 4,4' dimethyl-substituted biphenyl compound, comprising a feed comprising toluene and hydrogen in the presence of a hydroalkylation catalyst, in the effective manufacture of Contacting under conditions of a hydroalkylation reaction product of cyclohexyl)toluene. At least a portion of the hydroalkylation reaction product is dehydrogenated in the presence of a dehydrogenation reaction catalyst under conditions effective to produce a dehydrogenation reaction product comprising a mixture of dimethyl substituted biphenyl isomers. Thereafter, the dehydrogenation reaction product is separated into at least a first stream and at least one second stream, wherein the first stream comprises at least 50% of 3,4' and 4,4'-dimethylbiphenyl isomers by weight of the first stream. The second stream comprises one or more of 2, x' (where x' is 2', 3' or 4') and the 3,3'-dimethylbiphenyl isomer. |