- Email: [email protected]
02696 Using lime pretreatment to facilitate the enzymic hydrolysis of corn stover
07 Alternative energy sources (bioconversionenergy) 00102685 Promising industrial energy crop, Cynara cardunculus: a potential source for bromass production and alternative energy Piscioneri. 1. Energy Conversion & Managemenr, 2000, 41, (IO), 1091-I 105. The aim of the research work performed on Cynara carciunculus was to develop knowledge about growing this plant in Italy and the possibility of utilising it as an alternative raw material for the paper industry, energy or other valuable products. To achieve the objective, a set of experiments using a germplasm collection of nine genotypes has been conducted. The experimental results obtained have been reported in the present research paper 00102666 Properties of rapeseed oil for use as a diesel fuel extender McDonnell, K. er al. J. Am. Oil Che. Sot., 1999, 76, (5), 539-543. Rape-seed oil (referred to as SRO, i.e. semi-refined rape-seed oil) was analysed both chemically and thermally by being degummed and filtered in order to determine its suitability as a diesel fuel extender. The upper rate for inclusion of SRO with diesel fuel was 25%. This fuel blend had a phosphorus level of 2.5 ppm, which was comparable to rape Me esters (1.0 ppm phosphorus). Thermogravimetric analyses were used to estimate the cetane ratings of the fuels. A 25% SRO/diesel blend had an estimated cetane index of 32.4 compared to 38.1 for diesel fuel only. Differential scanning calorimetry and thermogravimetric analyses were used to compare the volatility ranges of the fuels. SRO needed higher temperatures for volatilization (i.e. 70-260” for diesel fuel versus 280-520” for SRO). This indicated poorer cold-starting performance of SRO compared with diesel fuel. SRO has a more favourable emissions profile than pure diesel fuel due to its low-sulfur, high-oxygen content. 00/02667 Pyrolysis of forestry biomass by-products in Greece Zabaniotou, A. A. Energy Sources, 1999, 21, (5), 395403. The technical characteristics of a biomass pyrolysis pilot plant recently constructed in central Greece are summarized in this article. The considerations involved in achieving successful pyrolysis technology and environmental and developmental goals are highlighted by reviewing technical and non-technical barriers associated with biomass treatment technology in Greece. Data from the start-up phase of the plant operation are presented and some aspects of the process are outlined. The capacity of the plant is 12OC-1450 kg/h, based on wet biomass (Arhu!us Unedo) and the pyrolysts temperature is approximately 400°C. Char yield is 1418% wt on dry basis and is of good quality consisttng of 76% carbon with heat content 6760 kcal/kg. Bio-oil includes 63% carbon and has a heat content of 6250 kc&kg. The limits of modelling. Experiences with bioenergy 00/02688 in practice-could models have predicted this outcome? Roos, A. and Rakos, C. Biomass and Bioenergy, 2000, 18, (4) 331-340. and Factors that complicate bioenergy model building ‘are presented discussed. Important aspects of ‘real-life’ energy systems that are difficult to represent in modelling are: the cost structure of energy production, information asymmetry, socioeconomic factors, household economics, strategic considerations and policy uncertainties. The modeller can employ different strategies in dealing with these problems. Complicating aspects can be quantified and integrated in the model, mentioned when the implications of the model are discussed or they may merit separate quantitative or qualitative investigations. The authors make some recommendations as to how these aspects could be considered in the modelling work to improve model accuracy. 00102689 The potential of biomass and animal waste of Turkey and the possibilities of these as fuel in thermal generating stations Acaroglu, M. el al. Energy Sources, 1999, 21, (4), 339-345. This paper studied the potential of biomass energy sources and animal solid wastes in Turkey as a source of fuel in thermal generating stations to produce electricity. The effects of biomass and lignite coal usage on the environment were reported comparatively. Considering total cereal products and fatty seed plants, approximately 50-65 million tons/year of biomass and 11,051 million tons of solid matter animal waste are produced, and 60% of biomass is seen as possible to use for energy purposes. The primary energy of applicable biomass was evaluated as 467-623 Peta Joule (PJ) and the energy of animal residues as 50,172 PJ, equal to 22-27% of Turkey’s annual primary energy consumption. 00102690 Thermochemical conversion of biomass Minowa, T. Nippon Enerugi Gakkaishi, 1999, 78, (4), 252-258. (In Japanese) The focus of this review is on thermochemical conversion technologies, such as flash pyrolysis of wood, high-pressure liquefaction, gasification and low-temperature gasification. They have been developed for the production of energy from biomass. This report describes the present status of the technologies on thermochemical conversion of biomass. 00102691 Thermodynamic evaluation for combined combustion of wastes in coal-fired furnaces Born, M. and Arnold, T. B&r. Ahfallwirfsch, 1999, 9, 141-158. (In German)
The problems encountered in the use of alternative fuels affecting the combustion process are pointed out based on thermodynamic calculations. It is shown that using the calculations, predictions can be made regarding the expected corrosion problems caused by the use of alternative fuels for brown coal. 00102692 Towards a sustainable Russian forest sector Carlsson, L. Nar. Rex. Forum, 2000, 24, (I ), 3 l-37 Russia’s forest resources are enormous, but despite almost ten years of transition, problems are still immense, in terms of commercial output and with respect to forest management. This arttcle suggests that one way of changing the situation is to introduce community management of forests. Using the Swedish forest commons as an example, this article argues that such a change in property rights will provide an alternative to massive privatization of the forests and to the undesirable continuation or strengthening of state forest management. Finally, it is concluded that such an introduction of new property rights regimes will not provide the solution to the problems, but rather will contribute to the establishment of a better institutional framework in the Russian forest sector. 00102693 Transesterification of heated rapeseed oil for extending diesel fuel Mittelbach, M. and Enzelsberger, H. J. Am. 011 Chem. ,Soc., 1999. 76, (5), 545-550. Biodiesel consists of fatty acid methyl esters and is well established as an alternative fuel. For economic reasons, used frying oil is an interesting alternative feedstock for biodiesel production. The chemical changes that occur during heating of rapeseed oil, in p’articular the formation of polymers, were investigated. Heated rapeseed oil samples were transesterified with methanol and analysed by size-exclusion chromatography during heating, the amount of polymers in the starting oil increased up to 15 wt%, but only up to 5 wt% in the transesterified samples. So during transesterification, dimeric and trimeric triglycerides in the starting oil were primarily converted into monomeric and dimeric fatty acid methyl esters. The amount of polymeric fatty acid methyl esters had a negative influence on fuel characteristics. After 6 hours of heating, the amount of carbon residue and after 16 hours the viscosity exceeded that of the existing specifications for biodiesel. It is possible to determine whether a waste oil is suitable for the production of biodiesel by the amount of polymers it contains. 00102694 Use of oil from sludge (OFS) technology for treatment of sewage sludges Bien, J. B. et al. Ga:. Wuda Tech. Sanit.. 1999, 73. (I). 19-22. (In Polish) Oil from sludge technology was used to study pyrolysis of sewage sludges. Similar calorific values were found in the pyrolysis chars to that of brown coal, however, they were composed of a substantial quantity of inorganic components, such as ashes. There was a significant amount of HaS and lower hydrocarbons in the gas product. It is necessary for the raw condensate to be processed further prior to its use, for example as a fuel oil. 00102695 Using cotton plant residue to produce briquettes Coates, W. Biomass and Bioenergy, 2000, lg. (3), 201-208. In Arizona, cotton (Gossypium) plant residue left in the field following harvest must be buried to prevent it from servtng as an over-wintering site for insects such as the pink bollworm. Most tillage operations employed to incorporate the residue into the soil are energy intensive and often degrade soil structure. Trials showed that cotton plant residue could be incorporated with pecan shells to produce commercially acceptable briquettes. Pecan shell briquettes containing cotton residue rather than waste paper were slightly less durable, when made using equivalent weight mixtures and moisture contents. Proximate and ultimate analyses showed the only difference among briquette samples to be a htgher ash content in those made using cotton plant residue. Briquettes made with paper demonstrated longer flame out time and lower ash percentage. compared to those made with cotton plant residue. 00102696 Using lime pretreatment to facilitate the enzymic hydrolysis of corn stover Kaar, W. E. and Holtzapple, M. T. Biomass and Biornerg,v, 2000, 18, (3), 189-199. Corn stover is an abundant, potential fermentation substrate. The most efficient means to produce fermentable sugars from corn stover is by enzymic hydrolysis, which is facilitated by thermochemical pre-treatment of the corn stover. Pre-treatment with slake lime (calcium hydroxide) increased the enzymic hydrolysis of corn stover nine times compared to untreated corn stover. The recommended pre-treatment conditions are: lime loading 0.075 g Ca(OH)a (g dry biomass) ‘; water loading 5 g Ha0 (g enzyme dry biomass) ‘; and heating for 4 h at 120°C. The recommended loading for the enzymi; saccharification of pre-treated corn stover is 10 and the recommended hydrolysis temperature is FPU (g dry biomass) 40°C. The enzymic conversion of the corn stover to monosaccharides, when pre-treated and saccharified as prescribed for 72 h, was about 60% cellulose, 47% xylan and 53% total available pplysaccharide. Increasing the and the hydrolysis time to enzyme loading to 25 FPU (g dry biomass) 7 days produced conversions of 88.0, 87.7 and 92.1% for the glucan, xylan and arabinan, respectively. These high conversions indicate that pre-
Fuel and Energy Abstracts
September 2000
299
07 Alternative
energy sources (solar energy)
treatment with lime can lead to corn stower polysaccharide conversions approaching 100%; the success of the saccharification after lime pretreatment depends on the enzyme loading. 00102697 Wastes with caloric content-a potential alternative fuel for manufacture of portland cement clinker Nedelescu, E. Morer. Consrr. (Bucharesr), 1999, 29. (I), 6669. (In Romanian) The results of chemical and energy investigations of the potential of wastes with caloric content, such as electrode waste and scrap tires as alternative fuels for manufacture of portland cement clinker. The characteristics of the wastes and the heavy metal emissions are provided. In addition, the feed points for these wastes in the burning line are described. 00102698 Willow growers in Sweden Rosenqvist, H. Biomms und Bioenergy. 2000, 18, (2), 137-145. The number of willow plantations on Swedish farmland increased considerably between 1991 and 1996. The main driving forces behind this development were: (1) The introduction in 1991 of a new agricultural policy in Sweden which, through deregulation, created lower grain prices and simultaneously introduced compensation for set-aside land as well as subsidies for willow plantations on surplus arable land; (2) higher taxes on fossil fuels; and (3) the existence of a biofuel market in Sweden based on forest fuels. This paper presents a statistical study of willow growers in southern and central-eastern Sweden. Data about willow growers and a stratified random sample of non-willow growers were acquired from the 1995 Farm Register compiled by Statistics Sweden. Willow growers are described according to geographical distribution, willow parcel sizes, farm sizes and farm types. Comparisons are also made with the population of farmers who are not growing willow. A high concentration of willow growers is recorded for central Sweden around Lake Malaren. Willow growers are more often in the age span 50-65 years and as compared to non-willow growers, have larger farms. They are less often focused on animal and milk production and more often on cereal and food crop production, when compared with other farmers. Implications of the Swedish experience for policy making in the fields of energy and agriculture are discussed.
Solar energy
A new high-flux solar furnace for high temperature 00/02699 thermochemical research Haueter, P. er crl. J. Sol. Energy Eng., 1999, I2 I, (I), 77-80. The operation of a new high-flux solar furnace, capable of delivering up to 40 kW at peak concentration ratios exceeding 5000, has commenced at PSI. Its optical design characteristics, main engineering features, and operating performance are described. Primarily, this solar facility will be used for investigating the thermochemical processing of solar fuels at temperatures as high as 2500 K. A study of the U-factor of the window with a high00102700 reflectivity Venetian blind Fang, X. D. S&r Energy, 2000, 68, (2) 207-214. The study focuses on the heat transfer coefficient (U-factor) of a window with a long-wave high-reflectivity Venetian blind (LWHRVB). Two side-byside hot boxes are built in a room for testing the window U-factors. The tested window systems are 100% glass area without frames, which are equivalent to the centre-of-glass of common windows. The slat of Venetian blinds is made of plastic with aluminium film glued on each side and the long-wave reflectivity is 0.93. The two types of window systems tested are the single glazing and the double glazing with the LWHRVB, respectively. The effect of slat slope-angles of Venetian blinds on U-factors is also studied. The empirical equations of the centre-of-glass U-factors are derived from the experimental data. The corrections for effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical. equations can be easily used to estimate the U-factor of the practical window with the LWHRVB. An energy efficient hybrid system of solar powered 00102701 water heater and adsorption ice maker Wang, R. 2. Solar Energy, 2000, 68, (2) 189-195. A new hybrid system of solar powered water heater and adsorption ice maker has been proposed. The working principle of the combined cycles of solar refrigeration and heating is described, theoretical simulation to the thermodynamic processes has been made. Experiments have been performed in a developed prototype hybrid system; it is verified that the hybrid system is capable of heating 60 kg water to about 90°C as well as producing ice at 10 kg per day with a 2 mz solar collector. 00102702 Application of titanium containing amorphous hydrogenated carbon films (a-C: HITi) as optical selective solar absorber coatings Schiiler, A. Solar Energy Morrricrls & Solar Cells, 2000, 60, (3), 295-307.
300
Fuel and Energy Abstracts
September
2000
A combined PVDiPECVD process for the vacuum deposition of titanium containing, amorphous hydrogenated carbon films is described. Elemental compositions of the deposited films have been determined by in situ core level photoelectron spectroscopy (XPS). The long-term stability of the plasma process has been demonstrated. Target poisening has not been observed. Optical selective surfaces have been fabricated by the deposition of a-C: H/Ti multilayers onto aluminium substrates. Even though layer thicknesses and stoichtometries have not yet been optimized, the experimental results are promising. Accelerated aging tests of these coatings have demonstrated their ageing stabiltty: the service lifetime is predicted to amount to more than 25 years. Raman spectroscopy has been used to monitor changes in the structure of the aged coatings. Degradation mechanisms are being discussed. 00/02703 Artificial neural networks for the prediction of the energy consumption of a passive solar building Kalogirou, S. A. and Bojic, M. Energy, 2000, 25, (5) 479491. Artificial neural networks (ANNs) have been used for the prediction of the energy consumption of a passive solar building. The building structure conststs of one room with an inclined roof. Two cases were investigated, an all insulated building and a building with one wall made completely of masonry and the other walls made partially of masonry and thermal insulation. The investigation was performed for two seasons: winter, for which the building with the masonry-only wall is facing south and summer, for which the building with the masonry-only wall is facing north. The building’s thermal behaviour was evaluated by using a dynamic thermal building model constructed on the basis of finite volumes and time marching. The energy consumption of the building depends on whether all walls have insulation, on the thickness of the masonry and insulation and on the season. Simulated data for a number of cases were used to train an artificial neural network (ANN) in order to generate a mapping between the above easily measurable inputs and the desired output, i.e. the building energy consumption in kWh. The simulated buildings had walls varying from 15 cm to 60 cm in thickness. The objective of this work is to produce another simulation program, using ANNs, to model the thermal behaviour of the building. A multilayer recurrent architecture using the standard back-propagation learning algorithm has been applied. The results obtained for the training set are such that they yield a coefficient of multiple determination (RI value) equal to 0.9985. The network was used subsequently for predictions of the energy consumption for cases other than the ones used for training. The coefficient of multiple determination obtained in this case was equal to 0.9991, which is very satisfactory. The ANN model proved to be much faster than the dynamic simulation programs. 00/02704 Bringing the sun to market Vale, B. A. and Vale, R. J. D. Solar Progress, 1999, 20, (4), 14. The paper compares and contrasts three examples of housing projects, which make use of solar design in an attempt to build, zero emissions housing. All three houses are in the United Kingdom, the Autonomous House, the Hockerton Housing Project and the Fiskerton Houses. The authors of this paper designed the three projects. All are attempts to make houses, which are more sustainable, in that they use no non-renewable energy in their day-to-day operation. Two of the examples, one urban and one rural, go further in their quest for sustainability in that they are designed to provide their own energy, water and sewage services on-site resources. The three projects show how radical ideas about performance can be tried out in one-off houses and refined to the point where they can be applied at no additional cost to conventional affordable homes. 00102705 Coal gasification by CO1 gas bubbling in molten salt for solar/fossil energy hybridization Matsunami, J. S&r Energy, 2000, 68, (3) 257-261. Coal gasification with CO1 (the Boudouard reaction: C + CO2 = 2C0. f&H” = 169.2 kJ/mol at 1I50 K), which can be applied to a solar thermochemical process to convert concentrated solar heat into chemical energy, was conducted in the molten salt medium (eutectic mixture of Na2COs and K>COs, weight ratio = l/l) to provide thermal storage. When CO2 gas was bubbled through the molten salt, higher reaction rates were observed compared to the case without CO* gas bubbling (CO* gas was streamed over the surface of the molten salt). Thus the coke formed by coal pyrolysis was well suspended in the molten salt by CO2 gas bubbling. When the CO2 flow rate was increased from I5 to 60 bmol/s, the CO evolution rate was increased (15-26 pmol/s). However, CO2 conversion efficiency was decreased (50-22%). Based on the maximum CO evolution rate (26 pmol/s), solar thermal energy from a solar farm (300 x 300 m2) could be converted to chemical energy at a rate of 50 000 kJ/s by the coal (23 ton as C) gasification process studied here. This assumes 50% solar heat to chemical energy conversion efficiency which can be generally obtained by the actual solar experiments. 00/02706 Compact linear fresnel reflector solar thermal powerplants Mills, D. R. Solrrr Energy, 2000, 68, (3), 263-283. This paper evaluates Compact Linear Fresnel Reflector (CLFR) concepts suitable for large-scale solar thermal electricity generation plants. In the CLFR, it is assumed that there will be many parallel linear receivers elevated on tower structures that are close enough for individual mirror rows to have the option of directing reflected solar radiation to two
The problems encountered in the use of alternative fuels affecting the combustion process are pointed out based on thermodynamic calculations. It is shown that using the calculations, predictions can be made regarding the expected corrosion problems caused by the use of alternative fuels for brown coal. 00102692 Towards a sustainable Russian forest sector Carlsson, L. Nar. Rex. Forum, 2000, 24, (I ), 3 l-37 Russia’s forest resources are enormous, but despite almost ten years of transition, problems are still immense, in terms of commercial output and with respect to forest management. This arttcle suggests that one way of changing the situation is to introduce community management of forests. Using the Swedish forest commons as an example, this article argues that such a change in property rights will provide an alternative to massive privatization of the forests and to the undesirable continuation or strengthening of state forest management. Finally, it is concluded that such an introduction of new property rights regimes will not provide the solution to the problems, but rather will contribute to the establishment of a better institutional framework in the Russian forest sector. 00102693 Transesterification of heated rapeseed oil for extending diesel fuel Mittelbach, M. and Enzelsberger, H. J. Am. 011 Chem. ,Soc., 1999. 76, (5), 545-550. Biodiesel consists of fatty acid methyl esters and is well established as an alternative fuel. For economic reasons, used frying oil is an interesting alternative feedstock for biodiesel production. The chemical changes that occur during heating of rapeseed oil, in p’articular the formation of polymers, were investigated. Heated rapeseed oil samples were transesterified with methanol and analysed by size-exclusion chromatography during heating, the amount of polymers in the starting oil increased up to 15 wt%, but only up to 5 wt% in the transesterified samples. So during transesterification, dimeric and trimeric triglycerides in the starting oil were primarily converted into monomeric and dimeric fatty acid methyl esters. The amount of polymeric fatty acid methyl esters had a negative influence on fuel characteristics. After 6 hours of heating, the amount of carbon residue and after 16 hours the viscosity exceeded that of the existing specifications for biodiesel. It is possible to determine whether a waste oil is suitable for the production of biodiesel by the amount of polymers it contains. 00102694 Use of oil from sludge (OFS) technology for treatment of sewage sludges Bien, J. B. et al. Ga:. Wuda Tech. Sanit.. 1999, 73. (I). 19-22. (In Polish) Oil from sludge technology was used to study pyrolysis of sewage sludges. Similar calorific values were found in the pyrolysis chars to that of brown coal, however, they were composed of a substantial quantity of inorganic components, such as ashes. There was a significant amount of HaS and lower hydrocarbons in the gas product. It is necessary for the raw condensate to be processed further prior to its use, for example as a fuel oil. 00102695 Using cotton plant residue to produce briquettes Coates, W. Biomass and Bioenergy, 2000, lg. (3), 201-208. In Arizona, cotton (Gossypium) plant residue left in the field following harvest must be buried to prevent it from servtng as an over-wintering site for insects such as the pink bollworm. Most tillage operations employed to incorporate the residue into the soil are energy intensive and often degrade soil structure. Trials showed that cotton plant residue could be incorporated with pecan shells to produce commercially acceptable briquettes. Pecan shell briquettes containing cotton residue rather than waste paper were slightly less durable, when made using equivalent weight mixtures and moisture contents. Proximate and ultimate analyses showed the only difference among briquette samples to be a htgher ash content in those made using cotton plant residue. Briquettes made with paper demonstrated longer flame out time and lower ash percentage. compared to those made with cotton plant residue. 00102696 Using lime pretreatment to facilitate the enzymic hydrolysis of corn stover Kaar, W. E. and Holtzapple, M. T. Biomass and Biornerg,v, 2000, 18, (3), 189-199. Corn stover is an abundant, potential fermentation substrate. The most efficient means to produce fermentable sugars from corn stover is by enzymic hydrolysis, which is facilitated by thermochemical pre-treatment of the corn stover. Pre-treatment with slake lime (calcium hydroxide) increased the enzymic hydrolysis of corn stover nine times compared to untreated corn stover. The recommended pre-treatment conditions are: lime loading 0.075 g Ca(OH)a (g dry biomass) ‘; water loading 5 g Ha0 (g enzyme dry biomass) ‘; and heating for 4 h at 120°C. The recommended loading for the enzymi; saccharification of pre-treated corn stover is 10 and the recommended hydrolysis temperature is FPU (g dry biomass) 40°C. The enzymic conversion of the corn stover to monosaccharides, when pre-treated and saccharified as prescribed for 72 h, was about 60% cellulose, 47% xylan and 53% total available pplysaccharide. Increasing the and the hydrolysis time to enzyme loading to 25 FPU (g dry biomass) 7 days produced conversions of 88.0, 87.7 and 92.1% for the glucan, xylan and arabinan, respectively. These high conversions indicate that pre-
Fuel and Energy Abstracts
September 2000
299
07 Alternative
energy sources (solar energy)
treatment with lime can lead to corn stower polysaccharide conversions approaching 100%; the success of the saccharification after lime pretreatment depends on the enzyme loading. 00102697 Wastes with caloric content-a potential alternative fuel for manufacture of portland cement clinker Nedelescu, E. Morer. Consrr. (Bucharesr), 1999, 29. (I), 6669. (In Romanian) The results of chemical and energy investigations of the potential of wastes with caloric content, such as electrode waste and scrap tires as alternative fuels for manufacture of portland cement clinker. The characteristics of the wastes and the heavy metal emissions are provided. In addition, the feed points for these wastes in the burning line are described. 00102698 Willow growers in Sweden Rosenqvist, H. Biomms und Bioenergy. 2000, 18, (2), 137-145. The number of willow plantations on Swedish farmland increased considerably between 1991 and 1996. The main driving forces behind this development were: (1) The introduction in 1991 of a new agricultural policy in Sweden which, through deregulation, created lower grain prices and simultaneously introduced compensation for set-aside land as well as subsidies for willow plantations on surplus arable land; (2) higher taxes on fossil fuels; and (3) the existence of a biofuel market in Sweden based on forest fuels. This paper presents a statistical study of willow growers in southern and central-eastern Sweden. Data about willow growers and a stratified random sample of non-willow growers were acquired from the 1995 Farm Register compiled by Statistics Sweden. Willow growers are described according to geographical distribution, willow parcel sizes, farm sizes and farm types. Comparisons are also made with the population of farmers who are not growing willow. A high concentration of willow growers is recorded for central Sweden around Lake Malaren. Willow growers are more often in the age span 50-65 years and as compared to non-willow growers, have larger farms. They are less often focused on animal and milk production and more often on cereal and food crop production, when compared with other farmers. Implications of the Swedish experience for policy making in the fields of energy and agriculture are discussed.
Solar energy
A new high-flux solar furnace for high temperature 00/02699 thermochemical research Haueter, P. er crl. J. Sol. Energy Eng., 1999, I2 I, (I), 77-80. The operation of a new high-flux solar furnace, capable of delivering up to 40 kW at peak concentration ratios exceeding 5000, has commenced at PSI. Its optical design characteristics, main engineering features, and operating performance are described. Primarily, this solar facility will be used for investigating the thermochemical processing of solar fuels at temperatures as high as 2500 K. A study of the U-factor of the window with a high00102700 reflectivity Venetian blind Fang, X. D. S&r Energy, 2000, 68, (2) 207-214. The study focuses on the heat transfer coefficient (U-factor) of a window with a long-wave high-reflectivity Venetian blind (LWHRVB). Two side-byside hot boxes are built in a room for testing the window U-factors. The tested window systems are 100% glass area without frames, which are equivalent to the centre-of-glass of common windows. The slat of Venetian blinds is made of plastic with aluminium film glued on each side and the long-wave reflectivity is 0.93. The two types of window systems tested are the single glazing and the double glazing with the LWHRVB, respectively. The effect of slat slope-angles of Venetian blinds on U-factors is also studied. The empirical equations of the centre-of-glass U-factors are derived from the experimental data. The corrections for effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical. equations can be easily used to estimate the U-factor of the practical window with the LWHRVB. An energy efficient hybrid system of solar powered 00102701 water heater and adsorption ice maker Wang, R. 2. Solar Energy, 2000, 68, (2) 189-195. A new hybrid system of solar powered water heater and adsorption ice maker has been proposed. The working principle of the combined cycles of solar refrigeration and heating is described, theoretical simulation to the thermodynamic processes has been made. Experiments have been performed in a developed prototype hybrid system; it is verified that the hybrid system is capable of heating 60 kg water to about 90°C as well as producing ice at 10 kg per day with a 2 mz solar collector. 00102702 Application of titanium containing amorphous hydrogenated carbon films (a-C: HITi) as optical selective solar absorber coatings Schiiler, A. Solar Energy Morrricrls & Solar Cells, 2000, 60, (3), 295-307.
300
Fuel and Energy Abstracts
September
2000
A combined PVDiPECVD process for the vacuum deposition of titanium containing, amorphous hydrogenated carbon films is described. Elemental compositions of the deposited films have been determined by in situ core level photoelectron spectroscopy (XPS). The long-term stability of the plasma process has been demonstrated. Target poisening has not been observed. Optical selective surfaces have been fabricated by the deposition of a-C: H/Ti multilayers onto aluminium substrates. Even though layer thicknesses and stoichtometries have not yet been optimized, the experimental results are promising. Accelerated aging tests of these coatings have demonstrated their ageing stabiltty: the service lifetime is predicted to amount to more than 25 years. Raman spectroscopy has been used to monitor changes in the structure of the aged coatings. Degradation mechanisms are being discussed. 00/02703 Artificial neural networks for the prediction of the energy consumption of a passive solar building Kalogirou, S. A. and Bojic, M. Energy, 2000, 25, (5) 479491. Artificial neural networks (ANNs) have been used for the prediction of the energy consumption of a passive solar building. The building structure conststs of one room with an inclined roof. Two cases were investigated, an all insulated building and a building with one wall made completely of masonry and the other walls made partially of masonry and thermal insulation. The investigation was performed for two seasons: winter, for which the building with the masonry-only wall is facing south and summer, for which the building with the masonry-only wall is facing north. The building’s thermal behaviour was evaluated by using a dynamic thermal building model constructed on the basis of finite volumes and time marching. The energy consumption of the building depends on whether all walls have insulation, on the thickness of the masonry and insulation and on the season. Simulated data for a number of cases were used to train an artificial neural network (ANN) in order to generate a mapping between the above easily measurable inputs and the desired output, i.e. the building energy consumption in kWh. The simulated buildings had walls varying from 15 cm to 60 cm in thickness. The objective of this work is to produce another simulation program, using ANNs, to model the thermal behaviour of the building. A multilayer recurrent architecture using the standard back-propagation learning algorithm has been applied. The results obtained for the training set are such that they yield a coefficient of multiple determination (RI value) equal to 0.9985. The network was used subsequently for predictions of the energy consumption for cases other than the ones used for training. The coefficient of multiple determination obtained in this case was equal to 0.9991, which is very satisfactory. The ANN model proved to be much faster than the dynamic simulation programs. 00/02704 Bringing the sun to market Vale, B. A. and Vale, R. J. D. Solar Progress, 1999, 20, (4), 14. The paper compares and contrasts three examples of housing projects, which make use of solar design in an attempt to build, zero emissions housing. All three houses are in the United Kingdom, the Autonomous House, the Hockerton Housing Project and the Fiskerton Houses. The authors of this paper designed the three projects. All are attempts to make houses, which are more sustainable, in that they use no non-renewable energy in their day-to-day operation. Two of the examples, one urban and one rural, go further in their quest for sustainability in that they are designed to provide their own energy, water and sewage services on-site resources. The three projects show how radical ideas about performance can be tried out in one-off houses and refined to the point where they can be applied at no additional cost to conventional affordable homes. 00102705 Coal gasification by CO1 gas bubbling in molten salt for solar/fossil energy hybridization Matsunami, J. S&r Energy, 2000, 68, (3) 257-261. Coal gasification with CO1 (the Boudouard reaction: C + CO2 = 2C0. f&H” = 169.2 kJ/mol at 1I50 K), which can be applied to a solar thermochemical process to convert concentrated solar heat into chemical energy, was conducted in the molten salt medium (eutectic mixture of Na2COs and K>COs, weight ratio = l/l) to provide thermal storage. When CO2 gas was bubbled through the molten salt, higher reaction rates were observed compared to the case without CO* gas bubbling (CO* gas was streamed over the surface of the molten salt). Thus the coke formed by coal pyrolysis was well suspended in the molten salt by CO2 gas bubbling. When the CO2 flow rate was increased from I5 to 60 bmol/s, the CO evolution rate was increased (15-26 pmol/s). However, CO2 conversion efficiency was decreased (50-22%). Based on the maximum CO evolution rate (26 pmol/s), solar thermal energy from a solar farm (300 x 300 m2) could be converted to chemical energy at a rate of 50 000 kJ/s by the coal (23 ton as C) gasification process studied here. This assumes 50% solar heat to chemical energy conversion efficiency which can be generally obtained by the actual solar experiments. 00/02706 Compact linear fresnel reflector solar thermal powerplants Mills, D. R. Solrrr Energy, 2000, 68, (3), 263-283. This paper evaluates Compact Linear Fresnel Reflector (CLFR) concepts suitable for large-scale solar thermal electricity generation plants. In the CLFR, it is assumed that there will be many parallel linear receivers elevated on tower structures that are close enough for individual mirror rows to have the option of directing reflected solar radiation to two