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Reactors circulating catalyst

Feed to the FCC unit is mixed with hot catalyst and steam in a reactor line called a riser. The ratio of catalyst oil feed can typically range from 4 1 to 9 1 by weight. Overall, FCC is an endothermic process. Heat provided by the hot, circulating catalyst is the prime source of energy driving the FCC process. In the riser, vaporized oil is cracked catalytically in less than two seconds. The vapors and catalyst flow out of the riser and into the reactor. At this point, most cracking reactions have occurred. [Pg.11]

Figure 24.9 A comparison of catalytic performances of iso-butane dehydrogenation on vanadium and on vanadium carbide catalysts. The reaction was carried out in a circulating batch reactor. The initial partial pressure of isobutane was 13.3 kPa Torr, which was mixed with He for a total pressure of 100 kPa. Figure 24.9 A comparison of catalytic performances of iso-butane dehydrogenation on vanadium and on vanadium carbide catalysts. The reaction was carried out in a circulating batch reactor. The initial partial pressure of isobutane was 13.3 kPa Torr, which was mixed with He for a total pressure of 100 kPa.
Acrylic acid is a high volume chemical, continuous processing is used. Similar catalysts are used for both reactions, but the catalysts and conditions are sufficiently different that the reactions are conducted separately. Bismuth molybdate and molybdenum vanadium oxides typically are the bases for the catalysts in the first and second reactions, respectively. Effluent from the first reactor can go directly to the second reactor wilfrout processing. Fixed bed, shell-and-tube, solid-catalyst reactors are used for the gas-phase reaction. Reactors are cooled with circulating molten salts. Additional process information is presented as needed. [Pg.1013]

In the fluid-catalyst process, finely divided catalyst powder is continuously circulated from reactor to regenerator and back again without mechanical means. The fluid process was originated by the Standard Oil Development Company, the research organization of the Standard Oil Company of New Jersey, in collaboration with The M. W. Kellogg Company and Standard Oil Company (Indiana). Other companies participating in the development were Anglo-Iranian Oil Company, Ltd., Shell Oil Company, The Texas Company, and Universal Oil Products Company. This process was first announced in 1941 (48). [Pg.320]

Provision is made in the regenerator to introduce oil (referred to as torch oil ) into the dense phase of catalyst to supply heat during startup of the unit or at any time during operation when it is desired to transfer more heat to the reactor via circulated catalyst than is liberated by combustion of coke. Introduction of torch oil is also a means of stopping afterburning by depleting the oxygen before the flue gas reaches the dilute phase. [Pg.336]

The entrained-flow reactor (Fig. 8.5) is used when very short contact times are required, as in the case of highly active catalysts that deactivate fast. In fluid catalytic cracking (FCC) the circulating catalyst also supplies part of the heat for the endothermic reaction. Depending on the catalyst loading one can distinguish dilute and dense phase risers. ... [Pg.380]

Davison Circulating Riser, Reactor Temperature 52 TC, Regenerator Full Bum, Feed Pre-Heat varied, Countrymark feed, 0.9003 g/cc 15°C, 0.3 wt.% S, 0.53 wt.% ConCarb., 90% Pt. 530 C. Metals-free, steam equilibrated catalysts. [Pg.345]

Catalysts CPS (Mettallated and Cyclic) steaming. Test Conditions Davison Circulating Riser, Reactor Temperature 521° C, Full Bum Regenerator, Countrymark feed. [Pg.346]

The H-Oil reactor (Fig. 21) is rather unique and is called an ebullated bed catalytic reactor. A recycle pump, located either internally or externally, circulates the reactor fluids down through a central downcomer and then upward through a distributor plate and into the ebullated catalyst bed. The reactor is usually well insulated and operated adiabatically. Frequently, the reactor-mixing pattern is defined as backmixed, but this is not strictly true. A better description of the flow pattern is dispersed plug flow with recycle. Thus, the reactor equations for the axial dispersion model are modified appropriately to account for recycle conditions. [Pg.2577]

There are processes in which the total amount of catalyst is entrained by the gas. The reactors then belong to the category of transport reactors. Examples are some of the present Fischer-Tropsch reactors for the production of hydrocarbons from synthesis gas and the modern catalytic cracking units. Fig 10.11 shows the Synthol circulating solids reactor. In the dilute side of the circuit, reactant gases carry suspended catalyst upward, and the fluidized bed and stand-pipe on the other side of the circuit provide the driving force for the smooth circulation of the solid catalyst. For the removal of heat, heat exchangers are positioned in the reactor. [Pg.890]

In 1979 Chem Systems initiated a program to develop a liquid-entrained catalyst reactor which would provide improved contacting of syngas with the catalyst in a three phase system (ref. 38). This reactor system uses much finer catalyst particles than the fluidized bed reactor, and the catalyst-liquid slurry circulates through the reactor. The syngas can be contacted with the catalyst-liquid slurry either counter currently or co-currently. It appears that this process is more efficient than the original fluidized bed process. However, a major problem with this type of three phase system will no doubt be the development of a suitable catalyst since it is unlikely that conventional co-precipitated Cu-ZnO-A Oj catalysts will have the desired characteristics, particularly mechanical strength. [Pg.105]

Stripped for solvent removal. The later Phillips "particle form" process is a slurry process in which the polymer precipitates as it forms. This process uses a circulating-loop reactor. Because of improved catalyst use efficiency, catalyst removal from the polymer is unnecessary. [Pg.346]

The concept of a circulating flow reactor was further developed in the Buss reactor technology (Figure 1.26). Large quantities of reaction gas are introduced via a mixer to create a well dispersed mixture. This mixture is rapidly circulated by a special pump at high gas/liquid ratios throughout the volume of the loop and permits the maximum possible mass transfer rates. A heal exchanger in the external loop allows for independent optimisation of heat transfer. For continuous operation, the product is separated by an in-line cross-flow filter which retains the suspended solid catalyst within the loop. Such a system can operate in batch, semi-continuous and continuous mode. [Pg.20]

Carbon deposits on the catalyst during the reaction and is burned off rvith air in the regenerator. This combustion reaction generates much heat which is used to preheat fresh feed or to produce steam. The catalyst, usually a chromia-base type, is finely divided and must be cheap, rugged, and not susceptible to poisoning by sulfur or water. In conunercial installations of 40,000 bbl per day capacity, the catalyst circulating from reactor to regenerator and return may amount to as much as 30,000 tons per day. [Pg.637]

At about the same time the concept of a standpipe to build up pressure was conceived in the work at Exxon. A dense column of aerated solids would build up a fluostatic pressure, similar to a true liquid. It was pictured that aeration gas had to be added to offset the effects of compression, the amount of aeration being proportional to catalyst flow rate down the standpipe. Without the standpipe it would not be practical to circulate catalyst at the high rate needed to transfer all of the heat release in the regenerator over to the reactor. [Pg.276]

The moving bed-type process that eventually won" was fluid catalytic cracking (FCC). The early developments for this process were accomplished by Standard (New Jersey). Work with fixed-bed reactors during the late 1930s convinced E. V. Murphree, vice-president in charge of development, to conclude that the only viable approach was to use circulating catalyst processing that would allow steady-state operations (4). He also made the decision to utilize a powdered catalyst (4). [Pg.142]


See other pages where Reactors circulating catalyst is mentioned: [Pg.511]    [Pg.511]    [Pg.243]    [Pg.215]    [Pg.7]    [Pg.29]    [Pg.35]    [Pg.37]    [Pg.102]    [Pg.364]    [Pg.516]    [Pg.289]    [Pg.27]    [Pg.6]    [Pg.11]    [Pg.243]    [Pg.332]    [Pg.321]    [Pg.326]    [Pg.331]    [Pg.420]    [Pg.2117]    [Pg.2573]    [Pg.183]    [Pg.243]    [Pg.226]    [Pg.647]    [Pg.2103]    [Pg.160]    [Pg.167]    [Pg.33]    [Pg.273]    [Pg.274]    [Pg.286]   
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