A process for producing terephthalic acid and/or dimethyl terephthalate

摘要

A process for producing terephthalic acid and/or dimethyl terephthalate includes contacting a toluene-containing reaction stream with a first catalyst under toluene disproportionation conditions to produce an intermediate product stream of para-xylene with negligible ortho-xylene. The first catalyst includes a crystalline molecular sieve which has an ortho-xylene diffusion rate of at least 50 minutes. The first catalyst can be modified by selectivation with a silicon compound or carbon compound. The intermediate product stream, without need for para-xylene purification, is oxidized to terephthalic acid or dimethyl terephthalate.