07 Alternative energy sources (bioconversion energy)

00/02656 Nonintrusive load disaggregation computer program to estimate the energy consumption of major end uses in residential buildings Marceau, M. L. and Zmeureanu, R. Energy Convers. Manage., 2000, 41, (13), 1389-1403. This paper presents a new computer program for non-intrusive disaggrega- tion of the total electricity consumption of a house into the major end uses. The computer program has two modes: (1) sampling and (2) evaluation. In the sampling mode, the operating characteristics of each end use are determined from data collected over a period of several days using at least one current sensor per appliance. In the evaluation mode, only the main electric entrance of the house is monitored and the electric signal is analysed to disaggregate the total energy consumption. The errors in estimating the energy shares of three major end uses (water heater, baseboard heater and refrigerator) are less than 10% for most evaluation scenarios,

00102657 Real electricity price reductions at last Spears, B. Energ,~ World. 2000, May, (279), 8-9. Electricity prices have fallen steadily for all but the largest consumers over the last few years, but the falls to date have been limited by lack of competition in power generation. Now, starting from the April electricity contract round, buyers have seen substantial price reductions as more CCGTs get on-line, plant divestment starts to bite and NETA approaches.

00102656 The (pseudo-) liberalisation of Russia’s power sector: the hidden rationality of transformation Opitz, P. Energy Policy, 2000, 28, (3) 147-155. This paper discusses the problems of adjustment of the Russian power sector to the challenges for building up a new institutional structure according to political and market requirements and uncovers the reasons why the implementation of a pool regulation model initiated in 1992 was not successful. It identifies the purely formal nature of implementation of the model as well as demonetarization and the non-payment problem as the special conditions in Russia which were important for shaping the regulation model which evolved in recent years instead. In two phases of the power sector’s institutional development, different incentives led to the emergence of a dual economic regulation model, in which elements of the Soviet command and supply system co-exist with elements of market and entrepreneurship. Prospects of further regulatory reform are expected to result not from political decisions, as was characteristic for regulatory reform in other countries, but from economic interest of the already established players in the power market.

00102659 UK electricity-a snapshot Hodgson, S. Energy World, 2000, May, (279), 16-17. Standards of service to customers have reached record levels and electricity networks are more reliable than ever, according to tbe fourth annual Electricity Industry Review, published by the Electricity Association.

00102660 Uncertainty analysis in life cycle inventory. Application to the production of electricity with French coal power plants Maurice, B. Journnl gfC/eaner Pro&c/ion, 2000, 8, (2), 95-108. Uncertainty assessment in LCAs is an important aspect for decision-makers to judge the significance of differences in product or process options. Stochastic models (e.g. Monte Carlo) are tools used in Life Cycle Inventory (LCI) to compute the uncertainty of cumulative emissions and resource requirements. However, one main problem when applying such models is the large number of unit processes that make up a product system. In this paper a combination of qualitative and quantitative approaches in uncertainty assessment is proposed for an efficient assessment of uncertainty. The qualitative assessment of data quality relies on data quality indicators, whereas the quantitative assessment uses Monte Carlo simulation. The effort to select accurate probability functions concentrates on data with a significant contribution to the cumulative results and/or with a high uncertainty. The probability function of selected data is estimated using different techniques, depending on the amount of information available. Some results are presented by applying the method on selected French coal-based electricity.

00/02661 Yorkshire prepares large customers for NETA Energy World, 2000, May, (279), 12-I 3. The Utilities Bill, currently undergoing parliamentary scrutiny, contains proposals that have the capacity to fundamentally alter the way electricity is bought and sold. According to the representation manager at Yorkshire Electricity, the new electricity trading arrangement will have significant implications for industrial consumers.

07 ALTERNATIVE ENERGY SOURCES

Bioconversion energy

00/02662 Assessing plantation biomass for co-firing with coal in Northern Indiana: A linear programming approach Nienow, S. Biomass and Bioenerg~, 2000, IX, (2) 125-135. Tightening environmental regulations and the signing of the Kyoto Protocol have prompted electric utilities to consider co-firing biomass with coal to reduce the levels of COz, SOz and NO, in stack emissions. This analysis examines the cost competitiveness of plantation produced woody biomass and waste wood with coal in electricity production. A case study of woody biomass production and co-firing in northern Indiana is presented. A Soli.~ (willow) production budget was created to assess the feasibility of plantation tree production to supply biomass to the utility for fuel blending. Co-firing with waste wood from primary and secondary wood processing activities and local municipalities also is considered. A linear programming model was developed to examine the optimal co-firing blend of coal and biomass while minimizmg variable cost, including the cost of ash disposal and material procurement costs. This model was used to examine situations where coal is the primary fuel and waste wood, willow trees, or both are available for fuel blending. The results indicate that co- firing woody biomass is cost-effective for the power plant. Sensitivity analysis explored the effect of waste wood prices on co-firing cost.

00102663 Bioenergy conversion studies of the organic fraction of MSW: assessment of ultimate bioenergy production potential of municipal garbage Rao, M. S. Applied Energp, 2000, 66, (I), 75-87. Batch digestion of municipal garbage was carried out under room temperature conditions (26 f 4°C) for 240 days. The ultimate biogas production potential of municipal garbage was found to be 0.661 m3/kg volatile solids. The experimental and ultimate gas yields obtained from municipal garbage compared well with the yields obtained from other types of solid wastes. A mathematical model was developed to predict both ultimate biodegradable substrate concentration as well as ultimate biogas production. The ultimate bioenergy yield, ultimate anaerobic biodegrad- ability of the substrate and the overall bioprocess conversion efficiency were evaluated from observations to be 18,145 kJ/kg volatile solids, 89.79 and 95.44%, respectively. The total biogas yield from municipal garbage per kg dry matter was observed to be 0.5 m3 and the average methane content of the biogas was observed to be 70 %vol.

00/02664 Biomass equations for determining fractions of common and grey alders growing on abandoned farmland and some practical implications Johansson, T. Biomass und Bioenerg)?, 2000, 18, (2) 147-159. A study was conducted in order to construct functions for above-ground biomass of fractions of young common alders (Alms glurinosa (L.) Gaertn.) and grey alders (Alms incuna (L.) Moench.). The constructed functions were designed to be used to predict the amount of biofuel produced from small areas. Biomass production was estimated in IO stands of common alder and I5 stands of grey alder, growing on abandoned farmland. The common alder stands were located in Sweden at latitudes ranging from 58O to 60” N and their total age varied from 4 to 36 years. Grey alder stands were located at latitudes ranging from 60” to 66” N and their total age varied from 5 to 35 years. A modified ‘mean tree technique’ was used to estimate biomass production, i.e. the tallest tree was chosen for sampling. The mean total dry weight above the stump level for common alder stands was 39 tonnes ha -’ with a range of 5 to 140 d.w. ha ’ and 61 tonnes ha with a range of 3 to 140 tonnes d.w. ha for grey alder stands. The mean annual increment for common alder stands was 3.1 I tonnes ha ’ y ’ (0.50- 7.71) and 4.38 tonnes ha-’ y -’ (0.6G9.32) for grey alder stands. In addition to estimating conventional dry weights of trees and tree components, specific leaf area, total surface area and leaf area index (LAI), among other measures, were estimated. The mean LA1 for common alder stands was 3. I6 and 2.03 for grey alder stands. The specific leaf area per tree for common alder was 16.1 m2 kg ’ and 14.4 m2 kg-’ for grey alder. Practical implications of the findings are discussed.

00102665 Biomass production and detoxification of wastewaters from the olive oil industry by strains of Penicillium isolated from wastewater disposal ponds Robles, A. Bioresource Tech&., 2000, 74, (3), 217-221. Olive mill wastewater (OMW) usually has to be diluted before biological treatment. In the present work seven strains of Penicilliuim isolated from OMW disposal ponds were tested for biomass production and biodegrada- tion of undiluted OMW. Best results were obtained by using strain P4, which formed 21.50 g (dry weight) of biomass per litre of undiluted wastewater after 20 days of cultivation. This and other strains also carried out an outstanding reduction of the chemical oxygen demand (COD) and

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07 Alternative energy sources (bioconversion energy)

the phenolic content of OMW, as well as a pH raise. The process could be accelerated by agitation. OMW fermented with Penicillium P4 was devoid of its initial antibacterial activity against Bacillus megarerium ATCC 25848.

00102666 Biomethanation of white rotted and brown rotted rice straw Ghosh, A. and Bhattacharyya, B. C. Bioprocess Eng., 1999,20, (4) 297-302. Biomethanation of white rotted and brown rotted rice straw was taken for the present investigation and their efficiency on biomethanation has been tested. White rot fungus Phonerochrrere chrysosporium (PC) and brown rot fungus Polyporus oswe$oformis (PO) was used to treat the rice straw. Approximately 34.73% and 46.19% in PO-treated straw and 21.12% and 31.94% in PC-treated straw increased biogas and methane production respectively. VFA production has also been increased in PC and PO treated straw compared to control straw which were 76.73% and 30.69%, respectively. During biomethanation, it has also been shown that reduction of COD occurs.

00102667 Carbon dynamics subsequent to establishment of switchgrass Ma, Z. Biomass and Bioenergy, 2000, 18. (2), 93-104. It is necessary to develop new, clean and renewable biofuels to mitigate the greenhouse effect and reduce dependence on non-renewable fossil fuels. Switchgrass (Panicum virgarum L.) has been chosen by the US Department of Energy as its model herbaceous energy crop in the Southeast due to high yields, low production costs, economic benefits and little competition from existing enterprises. However, knowledge of its influence on soil carbon dynamics is limited, as no systematic study of soil carbon dynamics in switchgrass culture has been conducted. The objective was to determine carbon dynamics subsequent to switchgrass establishment and the impact of cultural practices (row spacing and harvest frequency) on carbon biogeochemical characteristics in a sandy loam soil (Typic Paleudult) and a clay loam soil (Typic Hapludult). Results indicated that soil carbon characteristics changed over time after switchgrass establishment. Carbon mineralization, microbial biomass carbon, carbon turnover and percentage microbial biomass carbon in organic carbon was generally higher approximately two years after switchgrass planting than after its initial establishment in a sandy loam soil. Specifically, carbon mineralization increased by II2 and 254% at depths of O-15 cm and 15-30 cm, respectively; microbial biomass carbon increased by 168% in the top I5 cm of soil; and carbon turnover increased by I I6 and 255% at O-l 5 cm and 15-30 cm, respectively. Microbial biomass comprised 0.76 i 0.09% and 0.75 f: 0.19% of soil organic carbon in O-IS cm and 15-30 cm depths, respectively, of sandy loam soil, while it made up 1.37 ?z 0.22% and I.1 I rt 0.19% of soil organic carbon in the same soil depths in clay loam soil. Harvesting once resulted in more carbon turnover than harvesting twice in the sandy loam soil. Linear regression between soil carbon characteristics and switchgrass root weight, root carbon and root nitrogen returned to soil support the conclusion that soil carbon accumulation is positively related to root input. It appears that switchgrass establishment may have dual benefits as a source of renewable energy and as a means of improving soil quality. However, longer periods of study will be required to elucidate substantial gains in soil quality owing to switchgrass culture.

00102668 Characteristics of some biomass briquettes prepared under modest die pressures Ooi, C. C. and Siddiqui, K. M. Biomass and BioenergJ, 2000. 18. (3) 2233 228. Biomass material, including sawdust, rice husks, peanut shells, coconut fibres and palm fruit fibres, was densified into briquettes at modest pressures of 5-7 MPa using a piston and die type of press. The briquettes were tested to evaluate their relaxation behaviour, mechanical strength and burning characteristics. The sawdust briquettes were found to have better overall handling characteristics. But briquettes of different biomass materials required different optimum conditions of fabrication and generally showed a promising potential for further development.

00102669 Co-pyrolysis of coal/biomass and coal/sewage sludge mixtures Storm, C. el al. J. Eng. Gas Turbines Power, 1999, 121. (1). 55-63. Increasing interest is being focussed on biomass and sewage sludge in power plant technology as a source of carbon-dioxide-neutral fuels. A new way to reduce the consumption of fossil fuels could be the co-combustion or co-gasification of coal and biomass or coal and sewage sludge. In both cases, pyrolysis is the first step in the technical process. In order to obtain detailed information about the pyrolysis of coal/biomass and coal/sewage sludge mixtures as well as unblended fuels, investigations were carried out using an electric heated entrained flow reactor. The test runs provided information about fuel conversion efficiency, pyrolysis gas and tar yield, and composition of pyrolysis gas and tar. Besides gas and tar analysis investigations regarding the path of trace elements, like heavy metals, alkali, chlorine and nitrogen components, during the pyrolysis process varying different parameters have been carried out. The release of mineral components during pyrolysis has been obtained by the analysis of the fuel nitrogen distribution between pyrolysis gas, tar, and char, along with the ash composition.

00102670 Coal binder produced by liquefaction of biomass White, D. H. PCT Int. Appl. WO 99 29,812 (Cl. ClOL5/00), 17 Jun 1999, US Appl. 985,399, 5 Dee 1997. 53. The production of a coal agglomerate takes place due to the combination of coal fines with bio-binder base obtained from a biomass material sized in a shredder and processed by direct liquefaction in a liquefaction reactor in the absence of oxygen at typical temperatures ~230-370” and typical pressures 200-3000 psi, according to the known liquefaction process. The liquefied bio-binder base is mixed with fast pyrolysis tars in a mixer or is mixed with petroleum asphalt in the mixer, if desired, in order to modify its characteristics to meet specific needs of particular applications, and the resulting mixture is sprayed on coal fines preheated to 2120” and allowed to react at =150-205”. Combustible extenders and fillers, reinforcing fibres, and crosslinking agents may be mixed with the coal fines in the reactor/ mixer prior to combination with the bio-binder base to provide additional specific properties to the mixture. A conventional coal pelletizer is then used to pelletize the resulting mixed mass by the application of the necessary pressure.

00102671 Conflicting policies constrain residential biomass use Todd, J. So/or Progress, 2000, 21, (I), 2-4. Should we, or shouldn’t we, promote the use of firewood for residential space heating, cooking and water heating? On one hand, firewood, properly managed, is a renewable supply of energy, very cost competitive and with potential for multiple land uses during its growing period. On the other hand, incomplete combustion in open fireplaces and combustion in open fireplaces and wood-heaters means fine particles are released into the suburban atmosphere contributing to decreased air quality. These two aspects of residential firewood use are examined in the context of Australia’s greenhouse gas mitigation goals national air quality goals.

00102672 Cycle analyses of 5 and 20 MWe biomass gasifier based electric power stations in Hawaii Ishimura, D. M. PI al. J. Eng. Gas Turbines Power, 1999, 121, (I), 25-30. Process performance and viability assessments were made by thermodyn- amic cycle analyses of biomass gasifier-based electric power stations at two scales, nominally 5 and 20 MWe (net electric power output). Various configurations (Rankine, simple, steam-injected gas turbine and combined cycles) of a 5 MW standalone power station were modelled and a 20 MW biomass-based integrated gasifier combined-cycle cogeneration facility at a sugar factory was simulated. based on information gained from these analyses it will be determine whether biomass gasification-based electricity production is practicable in Hawaii and other sugar producing sites.

00/02673 Development of decision support system% for bioenergy applications Mitchell, C. P. Biomo.w and Bioenergy, 2000, 18, (4) 265-278. As the amount and complexity of information relating to the development of bioenergy systems increases so does the problem of how to handle the information in a manner which is helpful for decision making. Hypertext- based information systems and decision support systems are being developed to aid deployment of bioenergy systems. These approaches are discussed with reference to a short rotation forestry production information system and decision support systems for harvesting wood for energy from conventional forestry and short rotation forestry. The development of a model which integrates biomass production, conversion and electricity generation is discussed. Problems encountered when combining different models into an integrated model are addressed.

00102674 Ecological assessment of integrated bioenergy systems using the Sustainable Process Index Krotscheck, C. Biomass crnd Bioenergj, 2000, 18, (4) 341-368. Biomass utilization for energy production presently faces an uphill battle against fossil fuels. The use of biomass must offer additional benefits to compensate for higher prices: on the basis of a life cycle assessment (using BEAM to evaluate a variety of integrated bioenergy systems in connection with the Sustainable Process Index as a highly aggregated environmental pressure index) it is shown that integrated bioenergy systems are superior to fossil fuel systems in terms of environmental compatibility. The implemen- tation of sustainability measures provides additional valuable information that might help in constructing and optimising integrated bioenergy systems. For a set of reference processes, among them fast pyrolysis, atmospheric gasification, integrated gasification combined cycle (IGCC), combustion and steam cycle (CS) and conventional hydrolysis, a detailed impact assessment is shown. Sensitivity analyses of the most important ecological parameters are calculated, giving an overview of the impacts of various stages in the total life cycle and showing ‘what really matters’. Much of the ecological impact of integrated bioenergy systems is induced by feedstock production. It is mainly the use of fossil fuels in cultivation, harvesting and transportation as well as the use of fertilizers in short- rotation coppice production that impose considerable ecological pressure. Concerning electricity generation the most problematic pressures are due to gaseous emissions, most notably the release of NO,. Moreover, a rather complicated process (high amount of grey energy) and the use of fossil pilot fuel (co-combustion) leads to a rather weak ecological performance in contrast to other 100% biomass-based systems.

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