Abstract: Provided herein is a method and apparatus for selective deep catalytic cracking of petroleum naphthas or other hydrocarbon feedstocks. The feed comprising the hydrocarbons to be cracked and steam, in well-defined proportions, is first sent into a precatalytic zone (Zone I) of a cracking reactor, preferably a tubular reactor. In a preferred embodiment, Zone I, contains beads of some catalytically mildly active porous material such as quartz or quartz doped with Cr—Al, is set at a temperature T1. The gas steam flows then through a catalyst bed, called Zone II, where the catalytic reaction takes place. Zone II is set at temperature T2 and contains a zeolite type catalyst, preferably ZSM5 zeolite or, most preferably, a hybrid zeolite catalyst.
Abstract: Provided herein are monocomponent and hybrid catalyst compositions for use in steam-cracking of hydrocarbon feeds to selectively produce light olefins. The catalyst compositions being characterized by a first catalytic component comprising oxides of aluminum, silicon, chromium, and optionally, oxides of monovalent alkaline metals, and further comprising a binder, preferably bentonite clay. Preferably, the catalyst compositions will comprise a catalytic component in accordance with the following formula: (a) SiO2·(b) A12O3·(c) Cr2O3(d) alk2O, with alk being a monovalent alkaline metal, preferably selected from sodium, potassium and lithium. The second catalytic component is selected from a crystalline zeolite or a silica molecular sieve. Also provided in the present invention are methods of making the catalyst compositions.
Abstract: Provided herein are hybrid catalysts that are used in the deep catalytic cracking of petroleum naphthas or other hydrocarbon feedstocks, for the selective production of light olefins, in particular ethylene and propylene and BTX aromatics. The hybrid catalysts of this invention contain a chemically treated microporous crystalline silicate such as the pentasil-type silicalite, a mesoporous silica-alumina or zirconium oxide co-catalyst, into which may be incorporated aluminum oxide, molybdenum oxide, lanthanum oxide, cerium oxide or a mixture of aluminum and molybdenum oxides, and an inorganic binder such as bentonite clay.