The present disclosure provides a dehydrogenation catalyst composition and methods for making and using it. One aspect provides a dehydrogenation catalyst composition comprising a zinc-doped alumina carrier; and associated with the carrier, chromium, tin, zirconium and alkali metal, wherein the catalyst composition comprises: aluminum in an amount in the range of 51-88 wt %, calculated on an Al.sub.2O.sub.3 basis; zinc in an amount in the range of 0.1-10 wt %, calculated on a ZnO basis; chromium in an amount of 12-30 wt %, calculated on a Cr.sub.2O.sub.3 basis; tin in an amount in the range of 0.005-2 wt %, calculated on a SnO.sub.2 basis; zirconium in an amount in the range of 0.1-2 wt %, calculated on a ZrO.sub.2 basis; and alkali metal in an amount in the range of 0.1-5 wt %, calculated on a M.sub.2O basis.

Shaped catalyst compositions and methods for making and using the shaped catalyst compositions are provided. In an exemplary a catalyst active phase includes a MoVTeNbOx catalyst. The composition also includes a support phase, wherein the support phase includes fumed silica, and wherein the catalyst active phase and support phase form a heterogeneous mixture.

A catalyst for an oxidative dehydrogenation reaction that includes a carrier; a first coating layer provided on the carrier and including a metal oxide; and a second coating layer provided on the first coating layer and including a zinc ferrite-based catalyst, in which the metal oxide includes one or more metals selected from among Ce, K, Mg, La and Y.

Disclosed are methods for upgrading heavy aromatic waste streams, including polystyrene and other related materials, to chemical feedstocks. Process embodiments include feeding heavy aromatic waste streams to: a) hydrogenation followed by steam cracking followed by separation; and b) separation followed by: i) hydrogenation, and ii) hydrogenation followed by steam cracking followed by and separation. Each embodiment leads to production of ethylene, propylene, ethylbenzene, ethylbenzene precursors, or a combination thereof.

The disclosure concerns a propane dehydrogenation process, remarkable in that it comprises the steps of (a) providing a stream comprising at least propane; (b) providing at least one proton-conducting catalytic membrane, each proton-conducting catalytic membrane comprising an anode, an electrolyte layer disposed on top of the anode and a porous cathode disposed on top of the electrolyte layer, wherein the anode comprises at least one dehydrogenation catalyst; (c) feeding within the anode of said one or more proton-conducting catalytic membranes under propane dehydrogenation conditions the stream provided at step (a); and (d) recovering a first effluent comprising at least propylene. The disclosure also concerns a polypropylene manufacturing process and an installation to conduct said process.