Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.

Abstract: Disclosed is a method for inhibiting catalyst coke formation in the manufacture of an olefin. In particular, the method inhibits coke formation on a silicoaluminophosphate molecular sieve catalyst in the manufacture of ethylene and/or propylene. The method includes contacting an oxygenate-containing feedstock with a silicoaluminophosphate molecular sieve catalyst to form the olefin-containing product, and separating the olefin-containing product from the catalyst. An unregenerated portion of the separated catalyst is cooled before contacting with additional oxygenate feedstock to reduce coke formation on the catalyst.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with simulated moving bed adsorption (SiMBAC) to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is subjected to SiMBAC to obtain para-xylene product.

Abstract: Disclosed is a method for inhibiting catalyst coke formation in the manufacture of an olefin. In particular, the method inhibits coke formation on a silicoaluminophosphate molecular sieve catalyst in the manufacture of ethylene and/or propylene. The method includes contacting an oxygenate-containing feedstock with a silicoaluminophosphate molecular sieve catalyst to form the olefin-containing product, and separating the olefin-containing product from the catalyst. An unregenerated portion of the separated catalyst is cooled before contacting with additional oxygenate feedstock to reduce coke formation on the catalyst.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from C8 aromatics which uses a para-selective, non-acidic, medium pore molecular sieve of the MFI structure type and is operated isothermally in the vapor phase at elevated temperatures and pressures is integrated with simulated moving bed adsorption (SiMBAC) to produce para-xylene product. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, the feed is stopped, and lowering the partial pressure desorbs the pX and EB. The process effluent, which is rich in pX and EB, is subjected to SiMBAC to obtain para-xylene product.

Abstract: A pressure swing adsorption process to separate para-xylene and ethylbenzene from a C8 aromatics stream produced by toluene conversion uses a para-selective adsorbent, preferably a non-acidic, medium pore molecular sieve of the MFI structure type, and is operated isothermally in the vapor phase at elevated temperatures and pressures. A fixed bed of adsorbent is saturated with pX and EB, which are preferentially adsorbed, then the feed to the process is stopped. Lowering the partial pressure desorbs the pX and EB giving a pX/EB-rich effluent. A stream of non-adsorbed mX and oX may be obtained before desorbing pX and EB.