Showing papers in "International Journal of Hydrogen Energy in 2006"

TL;DR: In this article, a review is given of contemporary research on the hydrogen-fueled internal combustion engine and the emphasis is on light-to medium-duty engine research, where it is shown that due to low volumetric efficiencies and frequent preignition combustion events, the power densities of premixed or port-fuel-injected hydrogen engines are diminished relative to gasoline-powered engines.

TL;DR: In this paper, the influence of the choice of light source on measured photoconversion efficiencies for semiconductor photoelectrodes is examined, and it is concluded that reliable estimation of efficiency under standard conditions is best obtained by measuring the incident photon conversion efficiency (IPCE) as a function of wavelength, and integrating over the AM15 solar spectrum, or by measuring under sunlight with a similar zenith angle to that of the AM 15 spectrum.

TL;DR: In this paper, the performance of the biocatalyzed electrolysis of acetate has been evaluated using a model compound and the results showed that the system can achieve an overall efficiency of 53 ± 3.5 % with applied voltages as low as 0.3 − 0.4 V.

TL;DR: In this paper, the advantages and possible fields of applications of this type of electrolyzers in comparison with another one are reviewed and some results achieved up to now in PEM electrolysis, including last achievement of the authors, are summarized.

TL;DR: In this article, the degradation of polymer electrolyte membrane (PEM) fuel cells is classified into three categories: mechanical, thermal and chemical/electrochemical, along with detailed mechanisms for some degradations.

TL;DR: In this paper, a series of Cd 1 - x Zn x S ( x = 0 -0.92) photocatalysts were prepared by coprecipitation method and were calcined at 723 K under N 2 atmosphere.

TL;DR: A pilot-scale study of bio-hydrogen production was performed in a continuous flow anaerobic fermentation reactor (with an available volume of 1.48 m3) for over 200 days as mentioned in this paper.

TL;DR: In this article, the authors compared several candidate technologies that span the range from well developed to conceptual and compared their energy efficiency at a lower temperature range than the other alternatives, including high-temperature steam electrolysis (HTSE) coupled with an advanced gas reactor cooled by supercritical CO2 (S-CO2) and equipped with a supercritical co-product power conversion cycle.

TL;DR: In this paper, a new group of photocatalyst materials for water splitting into H 2 and O 2 under ultraviolet light irradiation was described, including tantalates and alkali and alkaline earth tantalates.

TL;DR: In this article, the authors investigated hydrogen (H2) and endproduct synthesis by Clostridium thermocellum in batch cultures using cellulosic sources (α -cellulose, shredded filter paper, and delignified wood fibers (DLWs)) and cellobiose.

TL;DR: In this paper, the effects of various parameters on biomass gasification in supercritical water were studied and the results showed that the gas yield of the biomass is sensitive to some of the parameters and the ways of reducing reactor plugging are obtained.

TL;DR: In this article, an anaerobic digester sludge was used as seed after a 100 ◦ C heat treatment for 30 min, and the sludge had a maximum specific hydrogen production rate of 2.1 L/(g-VSS d) and a hydrogen yield of 346 mL/g-carbohydrate, corresponding to 62.6% of stoichiometric yield.

TL;DR: The effect of gas sparging on continuous fermentative H 2 production was investigated in completely stirred-tank reactors (CSTR) using internal biogas, N 2 and CO 2 with various flow rates, indicating that the decrease of H 2 partial pressure by external gas sp arging had a beneficial effect on H 2 fermentation.

TL;DR: Interestingly, the variations in pH in the different tests bottles indicate that pH is an important parameter in the control of methanogenic activity.

TL;DR: Several supported metal (Ru, Rh, Pt, Pd, Ir, Ni, Co) catalysts were prepared and used for methane reforming with CO 2, while their activity was lower than that of Ni and Co as discussed by the authors.

TL;DR: In this article, a modified test rig has been developed from the former Cardiff University ‘Cloud Chamber’ for this experimental study, which comprises of a 250-mm length cylindrical stainless steel explosion bomb enclosed at one end with a stainless steel plug which houses an internal stirrer to allow mixing.

TL;DR: In this paper, Cadmium sulphide nanoparticles (6-12nm) are prepared by a precipitation process using different zeolite matrices as templates and characterized by UV-Vis, XRD, SEM, TEM and sorptometric techniques.

TL;DR: In this paper, the growth kinetics of hydrogen producing bacteria using three different substrates, namely sucrose, non-fat dry milk (NFDM), and food waste were investigated in dark fermentation through a series of batch experiments.

TL;DR: In this article, a novel process for hydrogen production by steam reforming of natural gas with inherent capture of carbon dioxide by chemical-looping combustion is proposed, which resembles a conventional circulating fluidized bed combustor with reforming taking place in reactor tubes located inside a bubbling fluidization bed.

TL;DR: In this paper, the authors reviewed the recent development of hydrogen production technologies, followed by an overview of the renewable energy sources and a discussion about potential applications for renewable hydrogen production in Hong Kong.

TL;DR: In this paper, a dynamic model for PEM electrolyzer based on conservation of mole balance at the anode and the cathode is presented, which is suitable for determining control strategy that will ensure efficient and reliable operation of the electrolyzer.

TL;DR: In this paper, the authors developed a dehydrogenation catalyst using a simple fixed-bed reactor that has a high stability and sufficient performance, which can generate hydrogen from methylcyclohexane with a conversion > 95 %, toluene selectivity > 99.9 %, hydrogen generation rate > 1000 Nm 3 / h / m 3 cat under the reasonable conditions of 593 K, ambient pressure, LHSV:2.0/h and co-feed hydrogen 5-20% in the feed.

TL;DR: In this article, X-ray photoelectron spectroscopic measurements showed that the N presented in TiO2 was in the state of both molecularly chemisorbed N2 and substituted N.

TL;DR: In this paper, a life cycle assessment of hydrogen and gasoline vehicles, including fuel production and utilization in vehicles powered by fuel cells and internal combustion engines, is conducted to evaluate and compare their efficiencies and environmental impacts.

TL;DR: In this article, the authors investigated the reaction of Mg and MgH 2 -Ni composite in pure water and 1m KCl and found that the reaction is complete within an hour in the presence of chloride ions.

TL;DR: In this article, experiments were conducted to investigate H2 production from glucose by mixed anaerobic cultures at various temperatures in the mesophilic range, and it was shown that glucose degradation rate and efficiency, H2 yield, and growth rate of H2-producing bacteria all increased as the temperature increased from 33 to View the MathML source.

TL;DR: In this article, a solar chemical reactor for steam-gasification of petcoke is presented, which features a continuous vortex flow of steam laden with steam particles confined to a cavity receiver and directly exposed to concentrated solar radiation.

TL;DR: In this article, a review of studies related to stability of Zr-based Laves phase system as well as in situ neutron diffraction investigation, the kinetics of TiFe, surface treatment of LaNi5 system, mechanically alloyed Mg-based hydrides and graphite nanofibres are reported.

TL;DR: In this article, a life cycle assessment of a combined advanced nuclear-high temperature electrolysis plant, focusing upon quantifying the emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides per kilogram of hydrogen produced, is presented in terms of the global warming potential (GWP) and acidification potential (AP) of the system.

TL;DR: In this article, the authors developed a dynamic model of PEM fuel cell system (FCS) that is capable of characterizing the mixed effects of gas flow, pressure and humidity.