Multi-stage reactor

The need to keep a concave temperature profile for a tubular reactor can be derived from the former multi-stage adiabatic reactor example. For this, the total catalyst volume is divided into more and more stages, keeping the flow cross-section and mass flow rate unchanged. It is not too difficult to realize that at multiple small stages and with similar small intercoolers this should become something like a cooled tubular reactor. Mathematically the requirement for a multi-stage reactor can be manipulated to a different form ... 

Figure 2.5 Possible technological solutions to bioprocess problems a) Fed-batch culture b) Continuous product removal (eg dialysis, vacuum fermentation, solvent extraction, ion exchange etc) c) Two-phase system combined with extractive fermentation (liquid-impelled loop reactor) d) Continuous culture, internal multi-stage reactor e) Continuous culture, dual-stream multi-stage reactor f) Continuous culture with biomass feedback (cell recycling). (See text for further details).

The transition probability matrix for the 3-stage reactor is given in the following and can easily be extended to a multi-stage reactor. For tp < t < tpi the matrix is of 12 by 12 since reactor 13 is yet inactive whereas for tpi t, it reads ... 

For the long-term durability of PEMFC, the acceptable CO concentration appears to be 10-100 ppm. To meet the requirement, three possible reactions can be considered preferential (or selective) oxidation, methanation, and Pd (or Pd alloy) membrane processes. Preferential oxidation (PrOx) of CO can convert CO to CO2, without excessive hydrogen oxidation (to water), to acceptable levels of CO using multi-stage reactors... 

The regeneration of the absorptive capacity of the spent scrubbing solution is accomplished in a multi-stage reactor system— three to five reactors in series. Both the limestone and the spent solution are fed to the first reactor and pass successively through the other reactors. The effluent from the reactor system is directed to the solids separation section. 

Multi-stage reactor first reactor for contacting feed with a medium pore shape-selective zeolite catalyst for converting the C3-olefinics to liquid hydrocarbons comprising C5+, in second stage the process conditions should be effective to convert a major amount of ethene... 

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