Abstract: The present patent application describes a method of regenerating a ruthenium catalyst for the hydrogenation of benzene, which comprises flushing the catalyst with inert gas in a regeneration step until the original activity or part of the original activity has been attained.

Abstract: Processes comprising: providing a starting material comprising one or more aromatic hydrocarbons, and having an aromatic sulfur compound content and a total sulfur content; reducing the aromatic sulfur compound content and the total sulfur content in the starting material; and hydrogenating the one or more aromatic hydrocarbons in the presence of a supported ruthenium catalyst and hydrogen.

Abstract: A process for preparing o-xylene comprises the steps of a) dimerizing 2-butenes to 3,4- and/or 2,3-dimethylhexenes and b) aromatizing the 3,4- and/or 2,3-dimethylhexenes under dehydrogenating conditions to give o-xylene and is suitable for the selective preparation of o-xylene.

Abstract: The present patent application describes a method of regenerating a ruthenium catalyst for the hydrogenation of benzene, which comprises flushing the catalyst with inert gas in a regeneration step until the original activity or part of the original activity has been attained.

Abstract: Process for preparing oligomers of alkenes having from 4 to 8 carbon atoms from a feed stream comprising such alkenes or hydrocarbon streams in which such alkenes are present over a nickel-containing, heterogeneous catalyst in n successive adiabatically operated reactors, where n is 2 or an integer greater than 2, at from 30 to 280° C. and pressures of from 1 to 300 bar, where the feed stream has a temperature Tin when it enters the first reaction zone, experiences a temperature increase in each reaction zone and, if this temperature increase is more than Tin+20° C., is brought to a temperature in the range Tin±20° C. before it enters a subsequent reaction zone, wherein the feed stream is divided and the feed substreams obtained in this way are fed to the 2 reactors, or if more than 2 reactors are used to at least 2 of the reactors, with addition of fresh feed in such a way that the temperature in one of the reactors is at most 20° C. higher than that in each of the other reactors used.