A bifunctional catalyst for example for conversion of oxygenates, the bifunctional catalyst comprising zeolite, alumina binder, Zn and P, wherein Zn is present at least partly as ZnAl.sub.2O.sub.4.

The invention is directed to a process to prepare propylene from a mixture of hydrocarbons having an olefin content of between 5 and 50 wt. % and boiling for more than 90 vol. % between 35 and 280° C. or from a hydrocarbon feed comprising paraffins, naphthenics, aromatics and optionally up to 10 wt. % of olefins, by first contacting the feed with a low acidic density cracking catalyst in a fixed bed reactor, separating propylene and subsequently contacting the residue with a high acidic density cracking catalyst in a fixed bed reactor at a more elevated temperature, separating propylene and recycling the residue to first and second cracking reactors. Aromatics may be added to first and second cracking step to improve cycle length.

Catalytic compositions and sequential catalytic methods are generally described. in some embodiments, a composition comprises a first catalyst comprising a Cu-modified zeolite, and a second catalyst capable of a coupling reaction between (a) an intermediate resulting from a reaction of a reactant at the first catalyst, and (b) a co-reagent, wherein a rate of diffusion of the co-reagent within one or more cages and/or pores of the first catalyst is lower than a rate of diffusion of the intermediate within the one or more cages and/or pores of the first catalyst.

A catalytic cracking process includes a step of contacting a cracking feedstock with a catalytic cracking catalyst in the presence of a radical initiator for reaction under catalytic cracking conditions. The radical initiator contains a dendritic polymer and/or a hyperbranched polymer. The dendritic polymer and the hyperbranched polymer each independently has a degree of branching of about 0.3-1, and each independently has a weight average molecular weight of greater than about 1000. The catalytic cracking process is beneficial to enhancing and accelerating the free radical cracking of petroleum hydrocarbon and promoting the regulation of cracking activity and product distribution; by using the process disclosed herein, the conversion of catalytic cracking can be improved, the yields of ethylene and propylene can be increased, and the yield of coke can be reduced.

A catalyst may include a metallic function derived from a metal constrained within cages and/or channels of a microporous material, wherein the cages and/or channels of the microporous material are defined by 8 tetrahedral atoms or fewer; and an acidic function derived from an additional zeolite having cages and/or channels defined by 10 or more tetrahedral atoms, wherein the microporous material providing the metallic function and additional zeolite providing the acidic function are coupled by a binder.

Embodiments of methods for converting gas condensate into a product stream comprising propylene comprise feeding gas condensate at a top region of a downflow high severity fluidized catalytic cracking reactor (HSFCC), where the gas condensate comprises: at least 50% by weight paraffins, and less than 0.1% by weight olefins. The method further comprises feeding catalyst to the top region of the downflow HSFCC reactor in an amount characterized by a catalyst to gas condensate weight ratio of about 5:1 to about 40:1, where the catalyst comprises nano-ZSM-5 zeolite catalyst having an average particle diameter from 0.01 to 0.2 μm, a Si/Al molar ratio from 20 to 40, and a surface area of at least 20 cm.sup.2/g. The method further comprises cracking the gas condensate in the presence of the catalyst at a reaction temperature of about 500° C. to about 700° C. to produce the product stream comprising propylene.

Processes and apparatuses for the production of propylene are provided. In an embodiment, a process is provided for production of propylene from an oxygenate feed comprising passing the oxygenate feed to an oxygenate-to-olefin reactor to contact the oxygenate feed with a catalyst to provide an effluent stream comprising olefins comprising ethylene, propylene and butylene. The effluent stream is separated in a product separation zone to generate a propylene product stream, an ethylene stream and a C.sub.4+ stream. The ethylene stream is reacted in an ethylene dimerization or oligomerization reactor in presence of a dimerization or oligomerization catalyst to provide a first process stream. The C.sub.4+ stream and the first process stream are cracked in a cracking reactor under cracking conditions to provide a cracked stream comprising additional amounts of ethylene and propylene. Finally, the cracked stream is passed to the product separation zone to recover additional amounts of propylene.

The present invention relates to a plant and a process for producing propylene at least one oxygenate, comprising a reactor for converting the reactant mixture into a product mixture which comprises propylene and also aliphatic and aromatic C.sub.5+ hydrocarbons, at least one distillation column for removing a C.sub.5+ stream, the C.sub.5+ stream comprising at least 90 wt % of the aliphatic and aromatic C.sub.5+ hydrocarbons of the product mixture, an extractive distillation column for separating the C.sub.5+ stream into an aromatics stream and an aliphatics stream, the aliphatics stream comprising at least 90 wt % of the aliphatics of the C.sub.5+ stream, and the aromatics stream comprising at least 90 wt % of the aromatics of the C.sub.5+ stream, and an aliphatics recycle line for at least partial recycling of the aliphatics stream to the reactor. According to the invention, an aromatics recycle line is provided which returns the aromatics stream at least partially as extractant into the extractive distillation column.

The application provides a catalyst for producing ethylene and propylene from methanol and/or dimethyl ether, and a preparation and application thereof. In the present application, a molecular sieve catalyst co-modified by rare earth metals and silanization is utilized. First, the material containing methanol and/or dimethyl ether reacts on the catalyst to generate hydrocarbons. The hydrocarbons are separated into a C.sub.1-C.sub.5 component and a C.sub.6.sup.+ component. Then the C.sub.6.sup.+ component is recycled to the feeding port and fed into the reactor after mixing with methanol and/or dimethyl ether. The above steps are repeated, to finally generate C.sub.1-C.sub.5 products, in which the selectivity for ethylene and propylene can reach more than 90 wt % in the C.sub.1-C.sub.5 component, so that the maximal yield can be achieved in the production of ethylene and propylene from methanol and/or dimethyl ether.

The present invention is a process for dehydrating an alcohol to prepare a corresponding olefin, comprising: (a) providing a composition (A) comprising at least an alcohol having at least 2 carbon atoms, optionally water, optionally an inert component, in a dehydration unit, (b) placing the composition (A) into contact with an acidic catalyst in a reaction zone of said dehydration unit at conditions effective to dehydrate at least a portion of the alcohol to make a corresponding olefin, (c) recovering from said dehydration unit an effluent (B) comprising : at least an olefin, water, undesired by-products including aldehydes and light products, optionally unconverted alcohol(s), optionally the inert component,
wherein, said composition (A)-providing step (a) comprises adding an effective amount of one or more sulfur containing compound capable to reduce the undesired by-products by comparison with a non introduction of such sulfur containing compound.

The component introduced at step (a) can be chosen from the group consisting of thiols, sulfides, disulfides.