K. T. Shenoy

Liquid phase selective hydrogenation of phenol to cyclohexanone over Ru/Al2O3 nanocatalyst under mild conditions

Highly monodispersed ruthenium nanoparticles were prepared via wet impregnation technique using RuCl3 · nH2O as a precursor. Ru nanoparticles were supported on Al2O3 to synthesize Ru nanocatalyst. The nanocatalyst was characterized by various techniques like XRD, SEM, TEM and BET analysis. The catalyst was used for hydrogenation of phenol under mild condition. The activity of the catalyst was checked by varying different parameters such as reaction temperature, time, H2 partial pressure, metal loading and catalyst amount. The catalyst was recovered from product and reused up to four times without significant loss in its catalytic activity. After a reaction time of 1 h, Ru/Al2O3 nanocatalyst showed high reactivity (82% conversion) and selectivity to cyclohexanone (67%) at 80°C and 20 bar hydrogen pressure.

CFD simulations to study the effects of wall protrusions on microfluidic mixing

In this study the effects of different types of wall protrusions on microfluidic mixing are studied using computational fluid dynamics (CFD) simulations. Two new protrusions, single first bracket protrusions and double opposite first bracket protrusions (DOFBPs), are conceptualized, evaluated through CFD simulations and compared to protrusions having standard geometrical shapes, e.g. rectangular protrusions, triangular protrusions and semicircular protrusions. In the range of Reynolds numbers covered in this study, the microchannel having an opposed T-junction and DOFBPs is found to provide good mixing. A hybrid approach relying on the modification of microfluidic junctions as well as wall protrusions for enhancing microfluidic mixing is also evaluated. The microchannel based on the hybrid approach of an OA 10°-20°-165° WY-junction and DOFBPs is also found to provide very good mixing for a wide range of Reynolds numbers.

Selective Hydrogenation of 4’,4”(5”)-Di-Tert-Butyldibenzo-18-Crown-6 Ether over Rh/γ-Al2O3 Nanocatalyst

Abstract Rh/γ-Al2O3 nanocatalysts with different metal loading were synthesized by two different techniques i. e. microemulsion and microwave irradiated solvothermal technique. Synthesized nanocatalysts were then successfully implemented for the hydrogenation of 4’,4”(5”)-di-tert-butyldibenzo-18-crown-6 ether (DTBuB18C6) at 70 bar, 353–393 K temperature and 5 h. It was observed that 3 wt% nanocatalyst obtained by microemulsion technique exhibited higher catalytic activity and resulted 40 % conversion with high selectivity towards cis-syn-cis di-tert-dicyclohexano-18-crown-6ether (CSC DTBuCH18C6).