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Propane nonoxidative and oxidative dehydrogenation reactions were investigated over bimetallic alumina supported Mo–Ni catalyst in a quartz fixed-bed reactor at 0.1 MPa within the temperature range of 773–973 K. Time-on-stream analysis showed that Mo–Ni catalyst is stable at 4 h reaction time during ODH, while it significantly deactivated during NODH due to heavy carbon deposition confirmed by TOC. Hydrogen production was considerable during both reactions. C3H6 production rate is significantly higher during NODH at T > 823 K. An increase of the propane partial pressure resulted in a decrease in propane conversion to 83.2%, and selectivity to C3H6 significantly enhanced from 7.1 to 16.3%. An increase in oxygen partial pressure increased propane conversion from 74 to 95%, while the selectivity to C3H6 was considerably diminished at 923 K.

This work details a parametric study of a laboratory-scale, novel stirred, multistage, countercurrent extractive reactor called the basket impeller column (BIC), as applied to the production of biodiesel. Waste frying oil was used as the feed, aqueous solutions of ethanol as the solvent and coreactant, while Candida antarctica lipase B immobilized on macroporous acrylic resin (Novozym 435) catalyzed the ethanolysis reaction. The effects of key operating parameters on the performance of the BIC, including stirring speed, the solvent-to-feed ratio (S/F), the solvent ethanol concentration (C EtOH,sol ), and the number of stages, were investigated with the objective of guiding process optimization. The BIC operated under conditions of low Damkoḧler number (Da ≤ 0.25) and the combined diffusional and reaction resistances in the organic phase appeared to be rate-limiting. A moderate stirring speed of 500 rpm was optimal for yield, while S/F had only a minor influence on BIC performance. Increasing the C EtOH,sol value from 20% (v/v) to 60% (v/v) had a dramatic effect, with an almost complete loss in yield, attributable to severe, permanent catalyst deactivation. Yield was proportional to the number of stages in the BIC, because of the associated rise in reactor space time and the Da value, with respect to key reactants.

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