This disclosure provides improved processes for converting aromatic hydrocarbons, such as benzene/toluene, alkylation, transalkylation, or isomerization. In an embodiment, a process comprises utilizing a passivated reactor to reduce deactivation of a molecular sieve catalyst. Additional measures such as the use of an auxiliary catalyst and/or an elevated reactor pressure may be used to further reduce deactivation of the molecular sieve catalyst.

This invention describes methods of alkylating isobutane which include a catalytic reaction system comprising a crystalline zeolite catalyst and a rare earth-modified molecular sieve adsorbent (RE—MSA). The crystalline zeolite catalyst comprises sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals; and up to 5 wt% of Pt, Pd and or Ni, and acid-site density (including both Lewis and Brønsted acid sites) of at least 100 .Math.mole/gm. The RE-modified molecular sieve adsorbent (Re—MSA) comprising sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 1 wt% of alkali metals, RE (rare earth elements) in the range of 10 to 30 wt% and transition metals selected from groups 9-11 in the range from 2 wt% to 10 wt; and acid-site density of no more than 30 .Math.mole/gm. The invention also includes methods of making RE—MSA.

Disclosed is a process for producing light olefins. In the process for producing light olefins by continuously bringing an alkane feedstock and a catalyst into contact to subject to a dehydrogenation reaction, the reaction pressure P of the dehydrogenation reaction is made 0.6-2 MPa and the volume space velocity H of the dehydrogenation reaction is made 500-1000 h.sup.−1. The light olefins production process of the present invention is simple and continuous in operation and has the characteristics of low investment, significant increase in yield of light olefins and high safety.

This disclosure provides improved processes for converting aromatic hydrocarbons, such as benzene/toluene, alkylation, transalkylation, or isomerization. In an embodiment, a process comprises utilizing a passivated reactor to reduce deactivation of a molecular sieve catalyst. Additional measures such as the use of an auxiliary catalyst and/or an elevated reactor pressure may be used to further reduce deactivation of the molecular sieve catalyst.

This invention describes methods of alkylating isobutane which include a catalytic reaction system comprising a crystalline zeolite catalyst and a rare earth-modified molecular sieve adsorbent (RE-MSA). The crystalline zeolite catalyst comprises sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals; and up to 5 wt % of Pt, Pd and or Ni, and acid-site density (including both Lewis and Bronsted acid sites) of at least 100 mole/gm. The RE-modified molecular sieve adsorbent (Re-MSA) comprising sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 1 wt % of alkali metals, RE (rare earth elements) in the range of 10 to 30 wt % and transition metals selected from groups 9-11 in the range from 2 wt % to 10 wt; and acid-site density of no more than 30 mole/gm. The invention also includes methods of making RE-MSA.

Disclosed is a process for producing light olefins. In the process for producing light olefins by continuously bringing an alkane feedstock and a catalyst into contact to subject to a dehydrogenation reaction, the reaction pressure P of the dehydrogenation reaction is made 0.6-2 MPa and the volume space velocity H of the dehydrogenation reaction is made 500-1000 h.sup.1. The light olefins production process of the present invention is simple and continuous in operation and has the characteristics of low investment, significant increase in yield of light olefins and high safety.

The invention provides a process for the preparation of an olefinic product, the process comprising the steps of: (a) reacting an oxygenate feedstock, comprising oxygenate, in an oxygenate reaction zone in the presence of a catalyst comprising a molecular sieve, at a temperature in the range of from 350 to 1000 C., to produce a reaction effluent stream, comprising at least oxygenate, olefin, water and acidic by-products; (b) cooling the reaction effluent stream by means of an indirect heat exchange to provide a cooled reaction effluent stream at a temperature greater than the dew point temperature of reaction effluent stream; (c) passing the cooled reaction effluent stream into a quench tower and contacting the cooled reaction effluent stream with a first aqueous liquid in the presence of at least one set of quench tower internals, to produce a quench tower gaseous stream comprising the olefinic product and a quench tower liquid stream comprising condensed material; and (d) separating the quench tower liquid stream into a hydrocarbon quench tower liquid stream and an aqueous quench tower liquid stream in the presence of one or more coalescers.

The invention relates to process for the preparation of an olefinic product comprising ethylene and/or propylene from an oxygenate, the process comprising the following steps: a) an oxygenate conversion step wherein a gaseous effluent comprising olefins and a water-soluble oxygenate is obtained; b) separation of water from the effluent; c) compression of the effluent; d) acid gas removal from the compressed gaseous effluent obtained in step c), wherein the compressed gaseous effluent is treated with a caustic solution in a caustic tower; and e) separating the olefinic product from the gaseous effluent treated in step d), wherein, in a final stage in the caustic tower, water-depleted compressed gaseous effluent is treated with a water stream that is essentially free of water-soluble oxygenate and a spent water stream comprising caustic and water-soluble oxygenate is obtained, which spent water stream is withdrawn from the process.