04 By-products related to fuels
Derived gaseous fuels 06/00590 Biomass gasification in near- and super-critical water: Status and prospects Matsumura, Y. et al. Biomass and Bioenergy, 2005, 29, (4), 269 292. The current status of biomass gasification in near- and supercritical water (SCWG) is reviewed. There are two approaches to biomass gasification in supercritical water. The first: low-temperature catalytic gasification, employs reaction temperature ranging from 350 to 600:C, and gasifies the feedstock with the aid of metal catalysts. The second: high-temperature supercritical water gasification, employs reaction temperatures ranging from 500 to 750:C, without catalyst or with nonmetallic catalysts. Reviews are made on reaction mechanism, catalyst, and experimental results for these two approaches. Engineering technologies for SCWG gasification, and an example of process analysis are also introduced. Finally, the authors' prognostications on the future prospects of this technology are offered.
06•00591 Kinetics of steam gasification of nascent char from rapid pyrolysis of a Victorian brown coal Bayarsaikhan, B. et al. Fuel, 2005, 84, (12 137, 1612 1621. Steam gasification of nascent char from rapid or slow pyrolysis of a Victorian brown coal was performed at 1073 1173 K in a novel droptube/fixed-bed reactor, in which steam-containing gas was forced to pass through an extremely thin bed of nascent char particles at sufficiently high velocity and large flux. The nascent char underwent parallel reactions consisting of non-catalytic gasification and catalytic one. The non-catalytic gasification followed first-order kinetics with respect to the fraction of unconverted carbon, and the rate constant was hardly influenced by operating variables such as heating rate for the pyrolysis, total pressure and even period of isothermal heating between the pyrolysis and gasification. The overall activity of inherent catalysts, alkali and alkaline earth metallic species, diminished due to volatilization and intra-particle deactivation, both of which were induced by the gasification. As a result, the catalytic gasification took place within a limited range of the char conversion up to 60 80%,. The initial catalyst activity and the kinetics of activity loss largely depended on the operating variables as above and also partial pressure of steam.
LNG 06/00592 maybe?
An environmentalist reassesses LNG: just say
Asmus, P. The Electricity Journal, 2005, 18, (4), 75 77. The need for the USA to import liquefied natural gas (LNG) as an alternative to coal is weighed up against the environmental implications of building an infrastructure to accommodate this. The author urges that both economic and environmental considerations are taken into account during any implementations.
Gas discovery boosts Chevron's LNG plans
Anon., P u m p Industry Analyst, 2005, (6), 4. Chevron Corp's Venezuela affiliate has made a significant natural gas discovery at the offshore Macuira 1X exploration well, advancing the company's plans to evaluate Venezuela's first liquefied natural gas (LNG) project.
Hydrogen generation and storage 06/00594 vehicles
Day, D. et al. Energy, 2005, 30, (14), 2558 2579. The objective of this project was to investigate and demonstrate production methods at a continuous, bench-scale level and generate sufficient material for an initial evaluation of a potentially profitable method of producing bioenergy and sequestering carbon. The novel process uses agricultural, forestry, and waste biomass to produce hydrogen using pyrolysis and reforming technologies conducted in a 50 kg/h pilot demonstration. The test runs produced a novel, nitrogenenriched, slow-release, carbon-sequestering fertilizer. Seven kilograms of the material were produced for further plant growth response testing. A pyrolysis temperature profile was discovered that results in a carbon char with an affinity for capturing CO2 through gas phase reaction with mixed nitrogen-carrying nutrient compounds within the pore structures of the carbon char. A bench-scale project demonstrated a continuous process fluidized-bed agglomerating process. The total amount of CO2 sequestration was managed by controlling particle discharge rates based on density. The patent-pending process is particularly applicable to fossil-fuel power plants as it also removes SO~ and NO~, does not require energy-intensive carbon dioxide separation and operates at ambient temperature and pressure. The method of sequestration uses existing farm fertilizer distribution infrastructure to deliver a carbon that is highly resistant to microbiological decomposition. The physical structure of carbon material provides a framework for building an NPK fertilizer inside the pore structure and creating a physical slow-release mechanism of these nutrients. The complete process produces three times as much hydrogen as it consumes making it a net energy producer for the affiliated power plant.
06/00596 Effective utilization of by-product oxygen from electrolysis hydrogen production Kato, T. et al. Energy, 2005, 30, (14), 2580 2595. To avoid fossil-fuel consumption and greenhouse-gas emissions, hydrogen should be produced by renewable energy resources. Water electrolysis using proton exchange membrane (PEM) is considered a promising hydrogen-production method, although the cost of the hydrogen from PEM would be very high compared with that from other mature technologies, such as steam methane reforming (SMR). In this study, the authors focus on the effective utilization of by-product oxygen from electrolysis hydrogen production and discuss the potential demand for it, as well as evaluating its contribution to improving process efficiency. Taking as an example the utilization of by-product oxygen for medical use, the authors compare the relative costs of hydrogen production by means of PEM electrolysis and SMR.
06/00597 Electrochemical energy storage in ordered porous carbon materials Vix-Guterl, C. et al. Carbon, 2005, 43, (6), 1293 1302. Highly ordered porous carbon materials obtained by a replica technique have been used for supercapacitor application and electrochemical hydrogen storage. For the preparation of the well-tailored carbons, MCM-48, SBA-15 and MSU-1 molecular sieves served as templates, whereas a sucrose solution, propylene and pitch were the carbon source. A careful physico-chemical characterization (CO2 and N2 adsorption, X-ray diffraction, electron microscopy observations) allowed the estimation of the total surface area, the pore size distribution, the micro/mesopore volume as well as the structure and the microtexture of the investigated carbons. The specific capacitance (F/g) and the hydrogen adsorption capacity in the carbon nanopores were correlated with the microtextural properties. Especially, a linear dependence has been found between the capacitance or the amount of electrochemically stored hydrogen and the ultramicropores (pores smaller than 0.7 rim) volume. It clearly indicates that in these carbons: (a) the major part of the electrical double layer is charged with nonsolvated ions; (b) ultramicropores play a determinant role for hydrogen storage.
A dynamic simulation tool for hydrogen fuel cell
Moore, R. M. et al. Journal o f Power Sources, 2005, 141, (2), 272 285. This paper describes a dynamic fuel cell vehicle simulation (FCVSim) tool for the load-following direct-hydrogen (DH) fuel cell vehicle. The emphasis is on simulation of the direct-hydrogen fuel cell system (FC System) within the vehicle simulation tool. This paper is focused on the subsystems that are specific to the load-following direct-hydrogen model. The four major subsystems discussed are the fuel cell stack, the air supply, the water and thermal management (WTM), and the hydrogen supply. The discussion provides the details of these subsystem simulations. The basic vehicle configuration has been previously outlined in an earlier study and is only briefly reviewed in this paper.
06•00595 Economical CO2, SO~ and NOx capture from fossilfuel utilization with combined renewable hydrogen production and large-scale carbon sequestration
Fuel and Energy Abstracts
BY-PRODUCTS RELATED TO F U E L S
06/00598 A novel electrode material for electric doublelayer capacitors Wei, Y.-Z. et al. Journal o f Power Sources, 2005, 141, (2), 386 391. In this study, a novel electrode material, modified activated carbon aerogel, has been developed for electric double-layer capacitors (EDLCs). This novel material was produced by the activation of carbon aerogel under CO2 flow, followed by surface modification with