Processes for commencing operations of fluidized catalytic reactor systems

A process for commencing a continuous reaction in a reactor system, the process comprising:

• introducing a catalyst to a combustor of a catalyst processing portion of the reactor system, wherein the catalyst initially has a first temperature of 500° C. or less;
• contacting the catalyst at the first temperature with a commencement fuel gas in the combustor, wherein the commencement fuel gas comprises at least 80 mol % fuel gas, where the fuel gas is selected from the group consisting of hydrogen, an alkane having at least 3 carbon atoms, an olefin having at least 2 carbon atoms, an aromatic hydrocarbon, and combinations of these, and contacting of the catalyst with the commencement fuel gas in the combustor at the first temperature of 500° C. or less causes catalytic combustion of the commencement fuel gas;
• maintaining the contacting of the catalyst with the commencement fuel gas until the temperature of the catalyst increases from the first temperature to a second temperature of at least 650° C.;
• and
• when the temperature of the catalyst is greater than or equal to the second temperature, introducing a regenerator fuel source to the catalyst processing portion, wherein:
• the regenerator fuel source comprises a supplemental fuel gas different from the commencement fuel gas and combustion of the regenerator fuel source maintains an operating temperature range in the catalyst processing portion.