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