Light continuous catalyst regeneration

Description The process consists of a reactor section, continuous catalyst regeneration (CCR) section and product-recovery section. Stacked radial-flow reactors (1) facilitate catalyst transfer to and from the CCR catalyst regeneration section (2). A charge heater and interheaters (3) achieve optimum conversion and selectivity for the endothermic reaction. Reactor effluent is separated into liquid and vapor products (4). The liquid product is sent to a stripper column (5) to remove light saturates from the C6 aromatic product. Vapor from the separator is compressed and sent to a gas recovery unit (6). The compressed vapor is then separated into a 95% pure hydrogen coproduct, a fuel-gas stream containing light byproducts and a recycled stream of unconverted LPG. 

The O atoms are produced when ozone is decomposed by ultraviolet light, as described previously. Notice that the net reaction, O, + O — 02 + 02, does not involve chlorine. Chlorine atoms act as continuously regenerated catalysts, and so even a low abundance can do a lot of damage. 

Loss of catalyst from the unit is measured by changes in inventory in the vessels and by the additions of make-up catalyst. Accuracy of the measurement from day to day is not high, but reliable data are accumulated over a period of time. An instrument has been developed for continuous recording of catalyst loss from the stack, which consists of an optical device (light source and thermopile) to measure concentration of solids, and a flowmeter to measure the flue-gas rate (268). The two devices are coupled by a mechanism which automatically multiplies catalyst concentration by the gas-flow rate. Catalyst carry-over from the regenerator of a unit equipped with a Cottrell precipitator has been measured by heat balance in the catalyst-return line from the Cottrell to the regenerator (34). 

The refinery blend contained a variety of light olefins, and contaminants (e.g., butadiene, oxygenates, sulfur) which are known to produce significant catalyst deactivation. These experiments were performed in a continuous, automated reaction/regeneration system... 

It has been mentioned in Section 4.1 that cupric chloride causes chlorination reactions. Thus, chlorinated aldehydes (see Eq. (9.26)) are the main by-products. Others include acetic acid and chlorinated acetic acids. Light ends are carbon dioxide, methyl, and ethyl chloride. By chlorination, oxidative, and hydrolytic reactions, oxalic acid is formed causing insoluble copper oxalate. In order to avoid an accumulation in the catalyst, it is continuously thermally decomposed by heating a small side stream in the regeneration step (reactor (i) in the one-stage, reactor (m)... 

Figure 4-6 Three catalytic reactors in series. This unit is used for the continuous catalytic reforming of petroleum naphthas, a key element in the process of producing gasoline for automobiles. The catalyst is comprised of platinum and another metallic component on an acidic support The catalyst slowly moves downward through the reactors and is regenerated after it leaves reactor 3 at the bottom of the picture. The reactors themselves are radial-flow reactors, as discussed in Chapter 3. (Copyright 2004 UOP LLC. All lights reserved. Used with permission.)...

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