Patent DE-102006015235-A1 (DE)
Title: Heterogeneously catalyzed partial dehydrogenation of hydrocarbon, comprises conducting feed stream of gaseous mixture comprising hydrocarbons through a fixed catalyst bed and filling of catalyst body along the flow direction of stream
Inventor: HECHLER CLAUS
IPC: C08F20/06
Filed: 2006-03-30
Abstract: Process for heterogeneously catalyzed partial dehydrogenation of a hydrocarbon, comprises conducting a feed stream of a gaseous reaction mixture comprising hydrocarbons, oxygen and hydrogen through a fixed catalyst bed; filling inert bodies and then catalyst body along the flow direction of the feed stream, under the condition that it needs lesser activation energy for the combustion reaction of the hydrocarbon with the molecular oxygen to form carbon dioxide and water; and dehydrogenating at least a partial quantity of hydrocarbon. Procedure for a heterogeneously-catalyzed partial dehydrogenation of at least a hydrocarbon, comprises: conducting a feed stream of a gaseous reaction mixture comprising oxygen, hydrogen and at least one hydrocarbon to be dehydrogenated, through a fixed bed catalyst, which is present in a column with a given cross-section; filling of inert bodies and then catalytically active filling with at least a catalyst body along the flow direction of the feed stream of the gaseous reaction mixture, under the condition that the filling is designed in such a manner that it at least in the inlet area along the flow direction of the feed stream of the gaseous reaction mixture needs lesser activation energy for the combustion reaction of molecular hydrogen with molecular oxygen to form water and/or for the combustion reaction of the hydrocarbon contained in the feed stream of the gaseous reaction mixture with the molecular oxygen to form carbon dioxide and water than that for the dehydrogenation of the at least one hydrocarbon to form the at least one dehydrogenated hydrocarbon; dehydrogenating at least a partial quantity of hydrocarbon, by which the feed stream of the gaseous reaction mixture is produced in the column; metering a gaseous feed stream I, which flows through the column with a volumetric flow rate (V1) on to the fixed bed catalyst and which contains molecular hydrogen and the at least one hydrocarbon, a feed gas II containing molecular oxygen and with a volumetric flow rate V2, before the catalyst bed, where the feed gas II is metered in such a manner in the form of a multitude of feed gas streams II that flow out of discharge openings A of a duct system that are present along the flow direction of the gaseous feed stream I before the fixed catalyst bed that (a) the directions of the multiple M of all the feed gas streams II withdrawing from the discharge openings A in the fictitious absence of the feed gas stream I include an angle an angle alpha of 90+-60[deg] with the flow direction of the feed stream I; (b) the distance D of the multiple M of all the discharge openings A of the catalyst bed, related to the flow velocity W of the feed gas stream I in the column is lower or the same as the induction time J of the gaseous feed stream of the reaction mixture multiplied by 2W; (c) with a projection of the centers of gravity of the multiple M of all the discharge openings A along the flow direction of the feed gas stream I in the projection plane E perpendicular to the flow direction of the feed gas stream I within the projection plane E for at least 75% of the projection surface traced out by the feed gas stream I, the number ZA of the center of gravities that are present in any surface area m 2> amounts to >= 10; (d) the individual feed gas streams II that withdraw from the discharge openings A that belong to the number ZA of the center of gravities of the discharge openings A deviate by not more than 50% from their numerical average; (e) within the number ZA of discharge openings, the distance d from the center of gravity of a discharge opening to that of an adjacent discharge opening amounts to not more than 2.(lm 2>/ZA) 1> > 2>, and (f) the ratio V1: V2 >= 8.