Texaco Inc.

Joel S Bittensky

Roy E Pratt

John P MacLean

James H Colvert

William R Menzies, Iii

Edward W Dillingham

An improved process for recovering energy via an expander turbine axial flow gas compressor set which utilizes hot regeneration gas recovered from the regeneration of fluidized catalytic cracking catalyst, and during turndown conditions when the output of the gas compressor is required to be increased by an excess amount to prevent surge and the excess amount is normally vented to the atmosphere prior to entering the regenerator to prevent afterburn, the process including the steps of:

Process for improving power recovery from regeneration gas under

An improved method is disclosed for controlling the temperature of the fluidized dense catalyst phase of the regeneration zone in a fluid catalytic cracking unit, wherein the coke laydown in the reaction zone is at a level such that the coke concentration of the partially deactivated catalyst from the reaction zone is not sufficient to provide the heat required to maintain the controlled temperature in the fluidized dense catalyst phase of the regeneration zone. In this method, torch oil is added to the partially deactivated catalyst in the spent catalyst transfer line in an amount such that the catalyst charged to the regeneration zone contains sufficient combustible material to provide the heat necessary to maintain the fluidized dense catalyst phase of the regeneration zone at the controlled temperature. Also, as a part of this improved method, the flow of oxygen-containing regeneration gas to the regeneration zone is regulated to provide sufficient oxygen to effect substantially complete combustion of the coke and torch oil to carbon dioxide and to provide an oxygen concentration in the regeneration flue gas within the range of from about 1 to about 10 mol%. Maintaining the oxygen concentration in the flue gas within this range results in a flue gas having a carbon monoxide content of about 500 ppm, or less, and preferably 10 ppm or less.

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Port Arthur, TX, United States of America

Joel S Bittensky