Aromatics prodn. by catalytic reforming of feedstocks - which are mixed with meta-xylene to increase ortho- and para-xylene yields

摘要

Aromatic hydrocarbons are produced by (a) mixing a feedstock contg. 0-18 vol. % aromatics and 0-8 vol. % C8 aromatics with 0.2-9 (pref. 3-7) vol. % of an additive comprising at least one C8 aromatic hydrocarbon, 40-100 (pref. 60-100) vol. % of which is m-xylene, so that the feedstock-additive mixt. contains 18 vol. % aromatics and 12 vol. % C8 aromatics; and (b) contacting the mixt. with a supported catalyst contg. =1 VIa, VIIa and/or VIII metal at 400-600 degrees C and an H partial pressure of 5-30 bar. The process can be used to produce benzene, toluene and xylenes from gasoline fractions (from steam cracking or catalytic reforming) or from naphthenes (by dehydrogenation) or paraffins (by dehydrocyclisation). The addn. (esp. recycling) of m-xylene increases the yield of the more useful o- and p- isomers hand has a favourable effect on the amts. of C5+ hydrocarbons and aromatic produced.