Natural gas and biofuel as feedstock for hydrogen productionon Ni catalysts

In this article, the aptitude of natural gas as feedstock in steam reforming process for hydrogen production is compared with that of different liquid fuels （pure compounds and commercial fuels）, with the aim to investigate the potentialities of biofuels to overcome the CO2 emission problems deriving from fossil fuel processing. The performances of a nickel based catalyst （commercially used in steam reforming of natural gas） were evaluated in terms of feed conversion and yield to the different products as function of temperature, space velocity and water/fuel ratio. Furthermore, a preliminary evaluation of catalyst durability was effected by monitoring yield to H2 versus time on stream and measuring coke formation at the end of experimental tests. High yields to hydrogen were obtained with all fuels investigated, whereas the deactivation phenomena, which are correlated to carbon deposition on the catalyst, were observed with all tested fuels, except for methane and biofuel.

Adsorption of Light Hydrocarbons on LTA and FER Zeolites

This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the application of adsorption processes in removal of light hydrocarbons from exhaust streams of the petrochemical industry and of light-duty gasoline vehicles under cold start conditions (C4-C5 paraffins and olefins). The materials investigated were 5A and Ferrierite zeolites, characterized by different pore opening and Si/Al ratio. Equilibrium isotherm curves at room temperature were determined by a gravimetric method on dehydrated zeolites, while breakthrough curves in dynamic tests were used to evaluate the adsorption properties of hydrated zeolites at low hydrocarbon partial pressure (0-1 kPa) and in experimental conditions close to those of a HC trap at the engine exhaust. The experimental results regarding the adsorption capacities were discussed with the aim to understand how the physico-chemical characteristics of the adsorbent material could affect its trapping capability in adsorbing different types of hydrocarbons.

Enhanced activity of bimetallic Fe-Cu catalysts supported on ceria toward water gas shift reaction: synergistic effect

Within the“hydrogen chain”,the high-temperature water gas shift reaction represents a key step to improve the H2 yield and adjust the H2/COx ratio to fit the constraints of downstream processes.Despite the commercial application of the high-temperature water gas shift,novel catalysts characterized by higher intrinsic activity(especially at low temperatures),good thermal stability,and no chromium content are needed.In this work,we propose bimetallic iron-copper catalysts supported on ceria,characterized by low active phase content(iron oxide+copper oxide<5 wt%).Fresh and used samples were characterized by inductively coupled plasma mass spectrometry,X-ray diffraction,nitrogen physisorption,scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy,and temperature programmed reduction in hydrogen to relate physicochemical features and catalytic activity.The sample with iron/copper≈1 and 4 wt%active phase content showed the best catalytic properties in terms of turnover frequency,no methane formation,and stability.Its unique properties were due to both strong iron-copper interaction and strong metal-support interaction,leading to outstanding redox behavior.