Integration of endothermic and exothermic reactions
The heatmanagement can be improved by coupling endothermic and exothermicreactions/processes. For example, in the rapid cycling reverse flowreactor, theendothermic propane dehydrogenation is coupled with the exothermic combustion of methane/carbondeposits. Other examplesinclude the packed bed membrane reactor with a dual function catalyst tocouple the oxidative coupling and steam reforming of methane, and the chemical-looping oxidative dehydrogenationof propane.
Forced unsteady-state operation
Heatexchange can be efficiently integrated by exploiting dynamic reactor operation, such as reverse flow (membrane) reactors, gas switching fluidized bed reactorsand dynamically operated packed beds, e.g. for the cryogenicseparation of CO2 from flue gasses and chemical looping combustion and reforming forelectricity production andhydrogen production respectively.
Liquid injection for heat integration
Industrialgas-phase polymerization reactors are often hampered by the dissipation of the heat produced by the exothermic polymerization reaction. We investigate indetail the dissipation of heat by injection of a liquid in fluidizedgas-solid suspensions (e.g. induced condensing agents, using the heat of evaporation to cool the reaction mixture and steam reforming of liquid fuels).
We study the formation of agglomerates and their effect on the bed hydrodynamics and heat transfer in order to develop design and operation guidelines. We employ a Discrete Particle Model (DPM) enhanced with mass and heat transfer, as well as infra-red assisted PIV (Particle Image Velocimetry) to validate our models.
Intensified drying concepts
Drying ofgranular solids is an important step in many processes in the food, pharma andchemical industry, and typically demands a large amount of energy. Our researchfocuses mainly on optimizing fluidized bed dryer operations; these processesare often used due to their simplicity in design, but pose processing problemssuch as channeling and agglomerate formation, which causes issues in heattransfer to the solids phase and evaporation of the moisture.
We have investigated various intensified concepts from the literature, such as theTorBed reactor, and relate our findings to existing industrial processes.Moreover, we have a wide range of powder characterization facilities at ourdisposal (TGA, particle size distribution measurements, etc), and we developnumerical models (DPM, phenomenological model) to characterize powder properties(e.g. critical moisture content) which all aids in the design ofindustrial-scale fluidized bed dryers.