Operating the reaction to supply oxygenate at an oxygenate proportion index of at least 0.5, and controlling {TAIL ~ weight hourly space velocity} and molar flow rate of oxygenate to the reactor to maintain a partial pressure velocity compensation factor of at least 0.1 psia−1hr−1, {HEAD ~ a prime olefin selectivity} of at least 45 wt % can be maintained 
Operating the reaction to supply oxygenate at an oxygenate proportion index of at least 0.5 , and controlling { TAIL ~ weight hourly space velocity } and molar flow rate of oxygenate to the reactor to maintain a partial pressure velocity compensation factor of at least 0.1 psia−1hr−1 , { HEAD ~ a prime olefin selectivity } of at least 45 wt % can be maintained
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH