Regeneration temperature control in a catalytic reaction system

A process for forming olefin product and regenerating coked molecular sieve catalyst, the process comprising the steps of:

• a) contacting an oxygen ate steam with a molecular sieve catalyst in a reactor to form an olefin product and a coked catalyst, the coked catalyst having a coke level of at least 1.5% by weight, based on total weight of the catalyst;
• b) contacting the coked catalyst with an oxygen-containing gas in a regenerator to form a regenerated catalyst having a coke level less than that of the coked catalyst, wherein the coked catalyst enters the regenerator at a temperature less than that of the regenerated catalyst that leaves the regenerator;
• and
• d) controlling temperature and coke levels in the regenerator by circulating the regenerated catalyst to the reactor at an average catalyst feedstock exposure index of at least 0.1 to less than 1.0, wherein the regenerated catalyst is circulated to the reactor and the coked catalyst is circulated to the regenerator at a rate to maintain a delta coke to delta T ratio of from 0.001 to 0.015 weight percent per ° C., wherein the delta coke is the level of coke on the coked catalyst minus the level of coke on the regenerated catalyst, and the delta T is the temperature of the regenerated catalyst leaving the regenerator minus the temperature of coked catalyst entering the regenerator,
• wherein non-reactive solids which contain no reactive molecular sieve are circulated with the regenerated and coked molecular sieve catalyst.

A process for controlling regenerator temperature in a system for forming olefin product from an oxygenate stream, the process comprising the steps of:

• a) providing the system for forming the olefin product from an oxygenate stream, the system comprising a reactor and regenerator connected via circulation lines;
• b) contacting the oxygenate stream with a molecular sieve catalyst in the reactor at a temperature effective to form an olefin product and a coked catalyst, the coked catalyst having a coke level of from 4 wt % to 10 wt %, based on total weight of the catalyst;
• c) contacting the coked catalyst with an oxygen-containing gas in a regenerator to form a regenerated catalyst having a coke level less than that of the coked catalyst;
• and
• d) controlling temperature and coke levels in the regenerator by circulating the regenerated catalyst to the reactor and the coked catalyst to the regenerator via the circulations lines, without passing the regenerated catalyst through a heat removal system, at an average catalyst feedstock exposure index of at least 0.1 to less than 1.0, wherein the regenerated catalyst is circulated to the reactor and the coked catalyst is circulated to the regenerator at a rate to maintain a delta coke to delta T ratio of from 0.001 to 0.015 weight percent per ° C., wherein the delta coke is die level of coke on the coked catalyst minus the level of coke on the regenerated catalyst, and the delta T is the temperature of the regenerated catalyst leaving the regenerator minus the temperature of coked catalyst entering the regenerator,
• wherein non-reactive solids which contain no reactive molecular sieve are circulated with the regenerated and coked molecular sieve catalyst.