Minimizing catalyst backflow in fluidized bed reactors

A process for introducing a feed comprising one or more aliphatic-containing compounds into a fluid bed reactor from a feed introduction device having a first end, a second end and a deviation zone, wherein the process comprises the steps of:

• (a) receiving a flow of the feed into the first end of the feed introduction device from a feed source;
• (b) deviating the flow of feed in the deviation zone about a deviation angle from the first end toward the second end, wherein the deviation angle is greater than 90 degrees;
• and
• (c) releasing the feed from the second end of the feed introduction device and into the fluid bed reactor to contact a molecular sieve catalyst, wherein the molecular sieve catalyst flows through the fluid bed reactor at a weight hourly space velocity from 1 hr−1 to 5000 hr−1 to maintain the catalyst in a fluidized state in the fluid bed reactor, and wherein the feedstock released into the fluid bed reactor, including diluent and reaction products within the reactor, flows through the fluid bed reactor at a superficial gas velocity of at least 0.1 meter per second to fluidize the molecular sieve catalyst within the reaction zone.