DE1645766

1,128,493. Catalytic processing of hydrocarbons. MOBIL OIL CORP. 13 Jan., 1967 [14 Jan., 1966], No. 1890/67. Heading C5E. A method of controlling the catalytic processing of a hydrocarbon-containing feedstock comprises subjecting a sample to a U.V. spectrometric analysis by passing light therethrough of a wavelength which characterizes the sample, generating a signal representative of the amount of light transmitted from or absorbed by the sample and applying said signal to control the processing. The process may be the catalytic cracking or a petroleum feedstock and the wavelength of light used is indicative of the catalytic coking tendency of the sample and is in the range 2800-3200 A. The signal may be related to the heat balance by controlling the feed rate of the coke-forming stock, combustion air rate to a catalyst regenerator, cooling air rate to said regenerator, and/or lift air rate to transport catalyst from said regenerator. The feedstock may also be subjected to NMR analysis to characterize the H-C groupings therein.