Highly selective N-olefin isomerization process using multiple parallel reactors

A continuous process for olefin skeletal isomerization of linear olefins to iso-olefins by contacting a linear butane-containing feed under olefin skeletal isomerization conditions, with an olefin skeletal isomerization catalyst comprising ZSM-35, which comprises operation of a plural parallel reactor system, said process comprising:

• a) isomerizing olefins at a weight hourly space velocity between 0.1 and 500 based on linear olefins in the feed in single reactor operation by directing a portion of said feed to a reactor containing freshly regenerated catalyst having a conversion activity in terms of alpha value of at least 2 and withdrawing iso-olefin rich product, thereby reducing the conversion activity of said catalyst and thereby selectivating said catalyst therein and directing another portion of said feed to another single reactor thereby selectivating said catalyst therein until at least a plurality of said reactors contain selectivated catalyst, and optionally simultaneously regenerating any deactivated catalyst in reactors not in isomerization operation;
• b) isomerizing olefins with selectivated catalyst by directing another portion of said feed to a plurality of said reactors simultaneously operating in parallel, containing selectivated catalyst, thereby reducing the weight hourly space velocity for each reactor by at least 25% relative to the single reactor operation of step a), until at least one of said reactors contains catalyst whose conversion activity has been reduced to a deactivated condition, withdrawing product, and optionally simultaneously regenerating any deactivated olefin skeletal isomerization catalyst in reactors not in isomerization operation;
• and
• c) repeating steps a) and b).

A continuous process for olefin skeletal isomerization of linear olefins to iso-olefins by contacting a linear butene and/or linear pentene-containing feed under olefin skeletal isomerization conditions, with an olefin skeletal isomerization catalyst, comprising ZSM-35, which comprises operation of a plural parallel reactor system having a first reactor, a second reactor and a third reactor, said process comprising:

• a) isomerizing olefins at a weight hourly space velocity between 0.1 and 500 based on linear olefins in the feed in single reactor operation by directing a portion of said feed to a reactor containing freshly regenerated catalyst having a conversion activity in terms of alpha value of at least 2 and withdrawing product, thereby reducing the conversion activity of the catalyst and thereby selectivating said catalyst therein and directing another portion of said feed to another single reactor thereby selectivating said catalyst therein until at least a plurality of said reactors contain selectivated catalyst, and optionally simultaneously regenerating any deactivated catalyst in reactors not in isomerization operation;
• b) isomerizing olefins with selectivated catalyst by directing another portion of said feed to a plurality of said reactors simultaneously operating in parallel, containing selectivated catalyst, wherein the weight hourly space velocity for each reactor is reduced by at least 25% relative to the single reactor operation of step a), until at least one of said reactors contains catalyst whose conversion activity has been reduced to a deactivated condition, withdrawing product, and optionally simultaneously regenerating any deactivated olefin skeletal isomerization catalyst in reactors not in isomerization operation;
• and
• c) repeating steps a) and b).