15 Environment (pollution, health protection, safety)
0502316 Optimization of the heterogeneous Fenton- oxidation of the model pollutant 2,4-xylidine using the optimal experimental design methodology Rios-Enriquez, M. et al. Solar Energy, 2005, 77, (5), 491 501. Among advanced oxidation processes (AOP), the photochemically enhanced Fenton reaction (photo-Fenton) may be particularly effective for the treatment of industrial waste water, and the possibility to use solar l ight is an addit ional advantage of this process. In the present work, a Fe3+-exchanged zeolite Ywas tested as a heterogeneous photo- Fenton catalyst for the degradation of the model organic pollutant, 2,4- xylidine. The performance of the catalyst was investigated using a bench photochemical reactor as well as solar reactors. The incident solar radiant powers (determined by ferrioxalate actinometry7 showed linear correlations with the outputs o fa Si-photodiode and a bolometer mounted on the solar unit, and could therefore be easily estimated from the on-line observation of the sensor outputs. The experimental design methodology was used for planning the experiments under normalized conditions and for modell ing the rates of 2,4-xylidine oxidation as a function of the concentrations of the additives (Fe 3 +-exchanged zeolite catalyst and hydrogen peroxide). Although a direct quantitat ive comparison between both reactors is difficult (different geometries and volumes, different spectral distr ibution of the radiation sources), the performance of the solar reactor appears to compare favourably with that of the bench photochemical reactor.
0502317 Safety demonstration tests using high temperature engineering test reactor Nakagawa, S. et al. Nuclear Engineering and Design, 2004, 233, (1 37, 301 308. Safety demonstrat ion tests using the high temperature engineering test reactor (HTTR) are conducted for demonstrat ing inherent safety features of high temperature gas-cooled reactors (HTGRs) as well as for providing core and plant transient data for val idation of HTGR safety analysis codes. The safety demonstrat ion tests are divided to the first phase and second phase tests. In the first phase tests, simulation tests of anticipated operational occurrences and anticipated transients without scram (ATWS) are conducted. The second phase tests will simulate accidents such as a depressurization accident (loss of coolant accident). The first phase tests simulating reactivity insertion events and coolant flow reduction events started in FY 2002. The first phase safety demonstrat ion tests will continue unti l FY 2005 and the second phase tests will be carried out from FY 2006.
0502318 Safety evaluation of the HTTR Kunitomi, K. et al. Nuclear Engineering and Design, 2004, 233, (1 3), 235 249. Japan Atomic Energy Research Institute ( JAERI) conducted the safety evaluation of the high temperature engineering test reactor (HTTR) considering various characteristics of the HTGR in order to confirm the adequacy of safety in all operational states. In the depressurization accident caused by a coaxial double primary pipe rupture, air ingress from the ruptured pipe oxidizes graphite blocks and fuel in the core. It is a unique accident only happened in HTGRs. JAER I established an evaluation procedure and developed analytical tools to evaluate the transient behaviour during the depressurization accident, especially, oxidation of the core and fission product release into the environment. In a regulatory review, the safety evaluation procedure and results of the depressurization accident were thoroughly discussed including the necessity of the containment vessel to prevent air ingress. The regulatory authorized that reactor safety was ensured in all off-normal states including the depressurization accident. The evaluation pro- cedure and evaluation tools will be applicable to the safety evaluation of future Japanese HTGRs. This paper describes the procedure and results of the safety evaluation especially focusing on the depressuriza- tion accident together with brief description of their analytical tools. Also, it presents topics in the regulatory review and R&D needs for the safety evaluation of future HTGRs.
0502319 Second stage energy conservation experience with a textile industry Palanichamy, C. and Babu, N. Energy Policy, 2005, 33, (5), 603 609. The Indian textile industrial sector is one of the oldest industrial sectors in the country, which is also energy intensive. It is currently undergoing several studies to reduce its energy consumption and hence energy conservation (EC) in this context offers an excellent opportu- nity. This paper, at the beginning, addresses the experiences of the authors with a textile industry, which has already carried out some fruitful EC measures. Then it highlights the EC potential availability and suggests some practicable environmental friendly EC policies suitable for the Indian context to achieve the estimated potential, and finally it highlights the Government's role in the EC endeavour.
0502320 Selective solar photodegradation of organopollutant mixtures in water Robert, D. et al. Solar Energy, 2005, 77, (5), 553 558.
338 Fuel and Energy Abstracts September 2005
Heterogeneous photocatalysis in a water solution is recognized as a method of totally el iminating most recalcitrant organic pollutants found in such solutions. The current work has tried to show that the heterogeneous photocatalysis process can also be a selective elimin- ation method in the case of the mixture: 4-hydroxybenzoic acid (4- HBz) and benzamide (Bz) at semi-pilot plant scale (190 dm 3) under conditions of solar irradiation. The photocatalysis experiments per- formed by us were done at the 'Plataforma Solar de Almeria' and were carried out in the compound parabolic collectors' CPC system. The study investigated in particular the influence of TiO2 loading, the effect of 4-HBz concentration and the effect of the presence of chloride anions and pH on the selectivity of the reaction process.
0502321 Solar photocatalysis, photodegradation of a commercial detergent in aqueous TiO2 dispersions under sunlight irradiation Oyama, T. et al. Solar Energy, 2005, 77, (57, 525 532. A commercial detergent whose major components are an anionic surfactant and a fluorescent whitening agent can be photodegraded in aqueous TiO2 dispersions under irradiation with concentrated sunlight in the presence of air. The degradation process followed apparent first- order kinetics in terms of the total sunlight energy impinging on the photoreactive system. The effects of (a) TiO2 loading, (b) circulation flow rate, and (c) pH of the reactant solution on the kinetics of decomposit ion of the detergent were examined. Under the prevail ing conditions, the optimal operational parameters for this detergent were,
1 1 respectively: TiO 2 loading, 6 g 1 ; circulation flow rate, 4.9 1 min ; and pH, 4.9. The rate of increase of the surface tension was greater than the rate of decrease of the concentration of the detergent. This study adds to our knowledge base in the effective use of sunlight irradiation to detoxify wastewaters containing undesirable detergents.
0502322 Technology assessment of thermal treatment technologies using ORWARE Assefa, G. et al. Energy Conversion and Management, 2005, 46, (57, 797 819. A technology assessment of thermal treatment technologies for wastes was performed in the form of scenarios of chains of technologies. The Swedish assessment tool, ORWARE, was used for the assessment. The scenarios of chains of thermal technologies assessed were gasification with catalytic combustion, gasification with flame combustion, incin- eration and landfilling. The landfil l ing scenario was used as a reference for comparison. The technologies were assessed from ecological and economic points of view. The results are presented in terms of global warming potential, acidification potential, eutrophication potential, consumption of primary energy carriers and welfare costs. From the simulations, gasification followed by catalytic combustion with energy recovery in a combined cycle appeared to be the most competitive technology from an ecological point of view. On the other hand, this alternative was more expensive than incineration. A sensitivity analysis was done regarding electricity prices to show which technology wins at what value of the unit price of electricity (SEK/kW h). Within this study, it was possible to make a comparison both between a combined cycle and a Rankine cycle (a system pair) and at the same time between flame combustion and catalytic combustion (a technology pair). To use gasification just as a treatment technology is not more appeal ing than incineration, but the possibility of combining gasification with a combined cycle is attractive in terms of electricity production. This research was done in connection with an empirical R&D work on both gasification of waste and catalytic combustion of the gasified waste at the Division of Chemical Technology, Royal Institute of Technology (KTH), Sweden.
0502323 The Brazilian air transportation sector in the context of global climate change: CO2 emissions and mitigation alternatives Simges, A. F. and Schaeffer, R. Energy Conversion and 3lanagement, 2005, 46, (47, 501 513. The purpose of this study is to discuss the participation of Brazil ian air transportation within the context of global climate change. It first briefly presents an inventory of COz emissions caused by airborne activities in Brazil and then shows a trend projection through to 2023, indicating the progress of these emissions, with eight possible mitigation strategies. The abatement potential for each of these strategies is also investigated. It is estimated that joint implementat ion of all these strategies within a typical projection of broad based sustainabil ity (based on renewable energy sources with fair social, economic and technological development) could result in an annual reduction in CO2 emissions caused by airborne activities in Brazil up to 28.5% (compared to the trend projection for 2023). It is also estimated that the emissions avoided through joint implementat ion of the mitigation alternatives analysed may well reach 82,000 Gg (or 109 g) of CO2 from 2003 through 2023.