Regenerator design

Other types of regenerators designed for specific adsorption systems may use solvents and chemicals to remove susceptible adsorbates (51), steam or heated inert gas to recover volatile organic solvents (52), and biological systems in which organics adsorbed on the activated carbon during water treatment are continuously degraded (53). 

Regenerator designs have changed since most units were built. If the unit test run indicates high CRC or if the catalyst will benefit from a lower CRC, the regenerator internals should be reviewed. If the data indicates wide temperature differences across the bed or afterburning, or if the unit has had some excursions, it should be examined. 

The regenerator design, either single-stage or two-stage, should provide uniform catalyst regeneration, increase flexibility for processing a variety of feedstocks, and minimize thermal and hydrothermal deactivation of the catalyst. 

Johnson, T. E., Resid FCC Regenerator Design, presented at the M.W. Kellogg Co. Refiing Technology seminar, Houston, Texas, February 9-10, 1995. 

Regenerator design - [CATALYSTS - REGENERATION - FLUID CATALYTIC CRAC KING UNITS] (Vol 5)... 

UOP fluid catalytic cracking a fluid process of using a reactor-over-regenerator design. 

The low cost of the heat-transfer surface along with the low pressure drop are the principal advantages of the regenerator. However, the intercontamination of fluid streams by mixing due to periodic flow reversals and the difficulty of regenerator design to handle three or more fluids have restricted its use and favored the adoption of brazed aluminum exchangers. 

In the MobO process, convetdon takes place in the absence of hydrogen, at a pressure of 3.10 Pa ab ote, and a temperature that rises progressively with time, 200 to 260"C The catalyst, whose LHSY is 3 in non operating conditions, has a life of two years. Intermediate regenerations, designed to bum the coke deposited, are carried out as soon as the temperature reaches 26Cf C. To mmimize dismutation reactions, toluene is used as a diluent at a rate of 10 to 12 per cent wdght of the reactor feed. 

The main considerations are the reaction kinetics, equilibrium relations, and heat of reaction. The relationship of these factors will determine the reactor configuration and the cooling water requirements. Obviously, physical and thermal data for all the flow streams will be needed. Catalyst activity with information on its decline with time and reactivation time will be needed for regeneration design purposes. 

As discussed in Chapter 7 (Column Breakthrough and Leakage ) counterflow regeneration designs not only provide for better operational efficiencies compared with coflow systems but leakage residuals are virtually eliminated such that the column effluent quality only begins to deteriorate as the resin begins to truly exhaust. 

Continuous processes employ circulating adsorbent or moving ports so that a portion of the adsorbent is always being regenerated. Design procedures for this type of process are complicated... 

P. J. Heggs, L. S. Bansal, R. S. Bond, and V. Vazakas, Thermal Regenerator Design Charts Including Intraconduction Effects, Trans. Inst. Chem. Eng., Vol. 58, pp. 265-270,1980. 

MODERN AND COMPETITIVE REGENERATOR DESIGNS FOR GLASS INDUSTRY... 

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