PSA process with reaction for reversible reactions

A process for the isomerization of a C.sub.5 /C.sub.6 hydrocarbon feed mixture comprising C.sub.5 /C.sub.6 normal paraffin components as reactants to produce a high octane product comprising mono and dimethyl branched paraffins, said process comprising the following steps:

• a) passing said feed mixture at reaction conditions including a reactor temperature and a reactor pressure in the presence of hydrogen to a fixed bed of a pressure swing adsorption and reaction zone to carry out at least one reversible reaction, said fixed bed containing a homogeneous mixture of a selective adsorbent for the adsorption of at least a portion of said mono methyl branched paraffins and said normal paraffins, and a catalyst selective for the isomerization of said feed mixture to produce said mono and dimethyl branched paraffins, isomerizing said reactants and withdrawing a first effluent stream comprising hydrogen and said high octane product;
• b) terminating the passing of said feed mixture to said fixed bed and countercurrently purging said fixed bed with a first purge stream comprising normal pentane to produce additional isomerization of said normal paraffin components and withdrawing a second effluent stream comprising mono methyl branched paraffins;
• c) countercurrently depressurizing said fixed bed to adsorption pressure and withdrawing a desorption effluent stream comprising said normal paraffins;
• d) repressurizing said fixed bed with a repressurization stream comprising hydrogen, and
• e) repeating steps (a) to (d) to provide a continuous process.