Dehydrogenation of methylcyclohexane over Pt/V2O5 and Pt/Y2O3 for hydrogen delivery applications

Dehydrogenation of methylcyclohexane (MCH) for hydrogen transportation and delivery application was carried out over 3 wt% Pt/V2O5 and 3 wt% Pt/Y2O3 catalyst. The catalytic activity was tested using a spray-pulse mode of reactor. Effective dehydrogenation of MCH under spray-pulse mode of reactant injection was observed. In terms of hydrogen evolu-tion rate at 60 min from start of reaction the activity of 958 mmol/g/min was obtained at temperature of 350 _C. Nearly 100% selectivity toward hydrogen was obtained. A relatively high conversion of 98% was observed with 3 wt% Pt/Y2O3 at 60 min using an advanced spray-pulse reactor system. The catalysts were characterized using x-ray diffraction pattern (XRD), CO-chemisorption metal analysis, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis

Catalytic dehydrogenation of cyclohexane over Ag-M/ACC catalysts for hydrogen supply

Dehydrogenation of cyclohexane to benzene has been carried out over Ag supported on activated carbon cloth (Ag/ACC) catalysts using a spray- pulse reactor. Hydrogen evolution was studied for hydrogen storage and supply system applications. The maximum rate of hydrogen evolution rate using monometallic Ag/ACC catalysts was 6.9 mmol/gmet/min for Ag loading of 10 wt%. An enhanced hydrogen evolution was observed by adding a small amount of noble metal (1 wt% Pt, Pd, Rh) to the Ag based catalysts. A synergistic effect was observed in the case of the Pt promoted catalysts on the hydrogen production were twice as compared to 10 wt% Ag catalyst only

Non-noble NieCu/ACC bimetallic catalyst for dehydrogenation of liquid organic hydrides for hydrogen storage

The effect of Cu on dehydrogenation activity of Ni has been observed when dehydroge-nation of methyl cyclohexane (MCH) was carried out by using bimetallic NieCu supported on activated carbon cloth (ACC) catalysts with various Ni to Cu ratios and constant total metal content of about 10 wt%. The dehydrogenation of MCH was studied for delivery of clean hydrogen to hydrogen fueling station. Catalysts have been synthesized by adsorption method and characterized by atomic absorption spectroscopy (AAS), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Among all combinations of this study 8 wt% Ni þ 2 wt% Cu/ACC was found to show strong synergetic effect. This catalyst exhibited relatively high H2 evolution rate 39.4 mmol/gmet/min during the dehy-drogenation of MCH. At the same time methane evolution rate was relatively low which indicated insignificant side reaction of hydrogenolysis. The study reveals that presence of specific amount of Cu enhances the dehydrogenation activity of Ni and suppresses the hydrogenolysis activity for the same. The NieCu/ACC catalyst may be a potential non-noble metal catalyst for dehydrogenation reaction

A feasibility analysis of hydrogen delivery system using liquid organic hydrides

The paper discusses the techno-economic feasibility of a hydrogen storage and delivery system using liquid organic hydrides (LOH). Wherein, LOH (particularly cycloalkanes) are used for transporting the hydrogen in chemical bonded form at ambient temperature and pressure. The hydrogen is delivered through a catalytic dehydrogenation process. The aromatics formed in the process are used for carrying more hydrogen by a subsequent hydrogenation reaction. Cost economics were performed on a system which produces 10 kg/h of hydrogen using methylcyclohexane as a carrier. With proprietary catalysts we have demonstrated the possibility of hydrogen storage of 6.8 wt% and 60 kg/m3 of hydrogen on volume basis. The energy balance calculation reveals the ratio of energy transported to energy consumed is about 3.9. Moreover, total carbon footprint calculation for the process of hydrogen delivery including transportation of LOH is also reported. The process can facilitate a saving of 345 tons/year of carbon dioxide emissions per delivery station by replacing gasoline with hydrogen for passenger cars. There is an immense techno-economic potential for the process

Catalytic Hydrogenation of Aqueous Phase Nitrate Over Fe/C Catalysts

Abstract Catalytic hydrogenation of nitrate in water has been carried out over Fe/C catalysts at ambient temperature using batch and continuous reactors. In batch reaction nitrate reduction activity of 2.9 mmol g-metal1 min-1 with nearly 100% selectivity towards nitrogen was obtained. Column study shows nitrate reduction below 5 ppm for an initial concentration of 100 ppm. Break through capacity, to reach concentration of 45 mg L-1, is more than 530 bed volumes. The catalysts were characterized using XRD, SEM–EDAX and XPS. With high selectivity and activity the catalytic system in present study could be a potential option for nitrate removal from water. Keywords Catalytic hydrogenation _ Fe/C catalyst _ Water treatment _ Nitrat

Efficient hydrogen supply through catalytic dehydrogenation of methylcyclohexane over Pt/metal oxide catalystsEfficient hydrogen supply through catalytic dehydrogenation of methylcyclohexane over Pt/metal oxide catalysts

This paper describes the results of experiments on dehydrogenation of methylcyclohexane over Pt supported on metal oxides (Pt/MO) and Pt supported on perovskite (Pt/Per) catalysts. The reaction is being considered as a means for delivery of hydrogen to fueling stations in the form of more easily transportable methylcyclohexane. Among Pt/MO catalysts, the best activity as determined by the hydrogen evolution rate was observed over Pt/La2O3 catalyst at 21.1 mmol/gmet/min. Perovskite-supported catalysts exhibited relatively higher activity and selectivity, with Pt/La0.7Y0.3NiO3 giving the best performance. This Pt/Per catalyst had an activity of ca 45 mmol/gmet/min with nearly 100% selectivity towards dehydrogenation. The catalysts were characterized using XRD, CO-chemisorption and SEM-EDXA techniques. The present study reports catalysts that minimize the use of Pt and explores tailoring the properties of the perovskite structure

Equilibrium isotherm and kinetic modeling of the adsorption of nitrates by anion exchange Indion NSSR resin

This paper describes the adsorption capacity of ion exchange Indion NSSR resin for removal of nitrates from aqueous solution. Adsorption capacity of resin was investigated under different conditions viz variations in adsorbent dose, initial concentrations of nitrate and pH. The fitting of the Freundlich, Langmuir and Dubinin– Radushkevich adsorption models to the equilibrium data was investigated. The equilibrium data obtained in this study were found to follow the Langmuir adsorption isotherm. The maximum sorption capacity was 119 mg/g as per Langmuir isotherm at 35 °C under this particular study. The rate parameters for the intra particle diffusion have been estimated for different initial concentrations. In batch adsorption processes, the adsorbate molecules diffuse in porous adsorbent and rate process usually depends on t0.5 rather than the contact time. The nitrate adsorption on Indion NSSR resin from aqueous solution follows first order reversible model. The nitrate adsorption capacity of ca 77 mg/g was observed for the Indion NSSR resin from the column study with specific conditions of operation