摘要：Fluidized beds enable good solids mixing,high rates of heat and mass transfer,and large throughputs,but there remain issues related to fluidization quality and *** this work I review modification techniques for fluidized beds from the perspective of the principles of process intensification(PI),that is,effective bubbling suppression and elutriation *** techniques are further refined into(1)design factors,*** the bed configuration,or the application of internal and external forces,and(2)operational factors,including altering the particle properties(***,density,surface area)and fluidizing gas properties(***,viscosity,or velocity).As far as two proposed PI principles are concerned,our review suggests that it ought to be possible to gain improvements of between 2 and 4 times over conventional fluidized bed designs by the application of these techniques.

摘要：Butyl-levulinate has been identified as a promising fuel candidate with high oxygen content. Its com- bustion in diesel engines yields very low soot and NOx emissions. It can be produced by the esterification of butanol and levulinic acid, which themselves are platform chemicals in a biorenewables-based chemical supply chain. Since the equilibrium of esterification limits the conversion in a conventional reactor, reactive distillation can be applied to overcome this limitation. The presence of the high-boiling catalyst sulfuric acid requires a further separation step downstream of the reactive distillation column to recover the catalyst for recycle. Optimal design specifications and an optimal operating point are determined using rigorous flowsheet optimization. The challenging optimization problem is solved by a favorable initialization strategy and continuous reformulation. The design identified has the potential to produce a renewable transportation fuel at reasonable cost.