Abstract: A catalytic process for the selective production of para-xylene comprises the step of reacting an aromatic hydrocarbon selected from the group consisting of toluene, benzene and mixtures thereof with a feed comprising carbon monoxide and hydrogen in the presence of a selectivated catalyst. The process includes a catalyst selectivation phase and a para-xylene production phase. In the catalyst selectivation phase, the aromatic hydrocarbon and the feed are contacted with the catalyst under a first set of conditions effective to increase the para-selectivity of said catalyst. In the para-xylene production phase, the aromatic hydrocarbon and said feed are contacted with the catalyst under a second set of conditions different from the first set of conditions effective to selectively produce para-xylene.

Abstract: A process for controlling the hydrogenation activity of a catalyst comprised of a crystalline molecular sieve and at least one hydrogenation metal selected from the group consisting of a Group VIIB metal, a Group VIII metal, and mixtures thereof. The process is carried out by contacting the catalyst with hydrogen under sufficient conditions of temperature and pressure and for sufficient time to reduce the hydrogenolysis activity of the catalyst. The catalyst prepared by the process finds application in the catalytic conversion of organic compounds, such as ethylbenzene dealkylation, xylenes isomerization, and the transalkylation of polyalkylaromatic hydrocarbons.

Abstract: A process for isomerizing xylenes in a feed containing xylenes is disclosed which process comprises: contacting the feed with a first isomerization catalyst in a first reactor under a first set of conditions effective to isomerize xylenes in the feed; and contacting the xylenes with a second isomerization catalyst in a second reactor under a second set of conditions effective to isomerize xylenes in the feed. The second reactor is typically a clay treater and contains a further catalyst effective under the second set of conditions to remove olefins in the feed. Any ethylbenzene in the feed is removed, either by dealkylation or isomerization, in the first reactor or in a third reactor upstream of the first and second reactors.

Abstract: A catalytic process for the selective production of para-xylene comprises the step of reacting an aromatic hydrocarbon selected from the group consisting of toluene, benzene and mixtures thereof with a feed comprising carbon monoxide and hydrogen in the presence of a selectivated catalyst. The process includes a catalyst selectivation phase and a para-xylene production phase. In the catalyst selectivation phase, the aromatic hydrocarbon and the feed are contacted with the catalyst under a first set of conditions effective to increase the para-selectivity of said catalyst. In the para-xylene production phase, the aromatic hydrocarbon and said feed are contacted with the catalyst under a second set of conditions different from the first set of conditions effective to selectively produce para-xylene.

Abstract: A process for isomerizing xylenes in a feed containing xylenes is disclosed which process comprises: contacting the feed with a first isomerization catalyst in a first reactor under a first set of conditions effective to isomerize xylenes in the feed; and contacting the xylenes with a second isomerization catalyst in a second reactor under a second set of conditions effective to isomerize xylenes in the feed. The second reactor is typically a clay treater and contains a further catalyst effective under the second set of conditions to remove olefins in the feed. Any ethylbenzene in the feed is removed, either by dealkylation or isomerization, in the first reactor or in a third reactor upstream of the first and second reactors.