Exxon flexicoking process


The millisecond barrier to fast kinetic studies was broken in tire late 1940s and early 1950s by two developments tire flash photolysis metliod of Norrish and Porter[2] and tire chemical relaxation teclmiques of Eigen [3], advances for which tire tliree shared tire 1967 Nobel Prize in chemistry. (The tenn relaxation techniques refers to kinetic methods in which a sudden change in an extensive parameter such as temperature, pressure, or electric field provides a perturbation from equilibrium small enough tliat any subsequent relaxation can be treated as a first order rate process, as discussed furtlier below. This is distinguished from flash photolysis in which absorjDtion of an optical photon creates a new physical or chemical state tliat is far from equilibrium.) The new teclmiques initially made possible transient kinetic studies of processes taking place on time scales as short as microseconds. The development of flash photolysis boosted tlie field of photochemistry tremendously by opening up transient photochemical and photophysical species such as free radicals and electronically excited states to direct observation and characterization. At tlie same time, tlie development of relaxation teclmiques opened up tlie field of fast solution kinetics by allow ing researchers to directly follow tlie time evolutions of fast unimolecular and bimolecular reactions such as dissociations, isomerizations and near diffusion-controlled ionic association reactions.  [c.2946]


See pages that mention the term Exxon flexicoking process : [c.2317]    [c.289]    [c.402]    [c.445]   
Chemistry of Petrochemical Processes (2000) -- [ c.60 ]