07 Alternative energy sources (bioconversion energy) named a pressurization factor. The relation between gas dynamic pressure and total system pressure was clarified from the related flow equations. 02/01532 Thermoeconomic optimization method as design tool in gas-steam combined plant realixation Attala, L. et al. Energy Conversion and Management, 2001, 42, (18). 2163-2172. In modern power plants design, not only high performances but also low capital investments have to be assured so that the final product proposed on the market could be competitive. Starting from this concept, in this work, we have realized a tool for a thermoeconomic evaluatton and optimization of thermal power plants which could give solutions to problems connected with the design of real systems. The model, using three programs and a set of cost correlations (obtained from collaboration with Nuovo Pignone-General Electric), can estimate the realization costs of a combined power plant as a function of the constructive and operation parameters. A test to verify the capacity of our model has been performed by simulating an existing plant. the results seem very good, and this tool be soon used also in the industry. 03/01533 Understanding the dynamics of electricity supply, resources and pollution: Pakistan’s case Qudrat-Ullah, H. and Davidsen, PI. Energy, 2001, 26, (6). 595406. To meet the compelling demand for electricity, the government of Pakistan introduced reforms in 1990-1991 that provide incentives for private sector investments, particularly in the electric power industry. In response to these incentives, most of the independent power producers (IPPs) offers included oil, coal and/or gas power plants. Hydroelectric generation, despite its rich resource base in the country, did not gain much attraction. This research provides an assessment of the existing policy subject to the constraints of environment concerns and available, but limited, resources. A dynamic simulation model that captures the dynamics of the sectors underlying the electricity system is built using system dynamics methodology. The policy assessment has been carried out in a three-dimensional context: the electricity supply; the resource import dependency; and the evolution of CO2 emissions. This research finds that the unchanged prolongation of the existing policy seems to effectively attract IPPs investments but not without potentially adverse consequences for the environment and the economy. 07 ALTERNATIVE ENERGY SOURCES Bioconversion energy Of!/01534 An alternative energy source from palm wastes industry for Malaysia and Indonesia Mahlia, T.M.I. et al. Energy Conversion and Management, 2001, 42, (IQ, 2109-2118. Malaysis and Indonesia are the largest producers of palm oil products. The palm oil industry has contributed the largest percentage income to the countries for many years. Moreover, palm oil has emerged as one of the world’s most important oils. About 90% of palm oil is used in food- related products world-wide, and the other 10% is used for basic raw material for soap. There are more than 100 palm oil processing mills in the two countries. As such, savings can be made by using the fibre and shell from the processing wastes as an alternative fuel for electricity generation for this industry. This paper deals with energy conversion from the fibre and shell of the industry wastes as an alternative energy source for the palm oil mill industry in the two countries mentioned. The study concentrates on using the fibre and shell obtained from the processing of palm oil as fuels for the boiler instead of fossil fuel. In addition, the possibility of excess air and fuel air ratio for the fibre and shell combustion process is also discussed. Furthermore, it has been found that the shell and fibre alone can supply more steam and electricity than is required. Some palm oil mills in Malaysia and Indonesia have applied this strategy successfully. The FELDA palm oil mill, with the capacity 30-60 tons FFB/h, in Sungai Tengi, Selangor, Malaysia has been selected for this research. 02/01535 An initial assessment of spent mushroom compost as a potential energy feedstock Williams, B.C. et al. Bioresource Technology, 2001, 79, (3). 227-230. The Irish mushroom industry has expanded rapidly in the last decade, particularly in the border counties. Its success has generated concern, however, as the production of spent mushroom compost (SMC) has increased. Until recently, SMC as an agricultural waste has been disposed of without due consideration to the environment. As County Councils increasingly address river pollution, restrictions will prevent expansion of the mushroom industry without an SMC waste manage- ment solution. This paper looks at the availability and composition of SMC and considers its potential as an energy feedstock. Variability in SMC composition was investigated by sampling from various locations over several months. Analyses showed that, on a dry ash free basis, SMC has a calorific value equivalent to sewage sludge which has been successfully fired for many years. Compositional analysis confirmed the dry fuel as consistent in make-up and showed the moisture content to vary within 60-77%, on an as-received basis. 02/01536 Biomass and nutrient removal by willow clones in experimental bioenergy plantations in New York State Adegbidi, H.G. er al. Biomass and Bioenergy, 2001, 20, (6), 399-41 I. The development of short-rotation intensive cultural (SRIC) willow systems as a source of bioenergy and bioproducts is growing in the northeastern and midwestern United States. Important data for sustainable management such as nutrient removal and nutrient use efficiency in willow bioenergy plantations is lacking. This study reports wood biomass production, annual removal of nutrients, and nutrient use efficiency in experimental plantings of SRIC willow and poplar at Tully, New York. Effects of clone, fertilization, irrigation, planting density, and harvest cycle were analysed. Annual biomass production of 15-22 dry Mg/ha removed 75-86, 10-11, 27-32, 52-79 and 4-5 kg/ha/ year of N, P, K, Ca and Mg, respectively. For all the variables studied, the responses depended on clone. Fertilization and irrigation increased rates of nutrient removal by means of increased biomass production. Unlike planting density, harvest cycle significantly affected rates of nutrient removal and nutrient use efficiency. For clone SVl (Salix dasyclados), an irrigated and fertilized planting with a density of 36,960 trees/ha harvested on a 3-year rotation had the highest biomass production and nutrient use efficiency, and the lowest rates of nutrient removal. The annual harvest cycle had the lowest nutrient use efficiency and the highest annual removal of nutrients suggesting that this choice would be most appropriate for biomass crops that are to be used as buffer strips to manage nutrient runoff from agricultural fields. An appropriate choice of clone, planting density, and harvest cycle could tailor the rates of nutrient removal and nutrient use efficiency to match the objective of the planting. 02101537 Biomass derived producer gas as a reciprocating engfne fuel-an experimental analysis Sridhar, G. er al. Biomass and Bioenergy, 2001, 21, (I), 61-72. This paper uncovers some of the misconceptions associated with the usage of producer gas, a lower calorific gas as a reciprocating engine fuel. This paper particularly addresses the use of producer gas in reciprocating engines at high compression ratio (17:1), which hitherto had been restricted to lower compression ration (up to 12:l). This restriction in compression ratio has been mainly attributed to the auto- ignition tendency of the fuel, which appears to be simply a matter of presumption rather than fact. The current work clearly indicates the breakdown of this compression ratio barrier and it is shown that the engine runs smoothly at compression ratio of 17:l without any tendency of auto-ignition. Experiments have been conducted on multi-cylinder spark ignition engine modified from a production diesel engine at varying compression ratios from 11.5:1 to 17~1 by retaining the combustion chamber design. As expected, working at a higher compression ratio turned out to be more efficient and also yielded higher brake power. A maximum brake power of 17.5 kWe was obtained at an overall efficiency of 21% at the highest compression ratio. The maximum de-rating of power in gas mode was 16% as compared to the normal diesel mode of operation at comparable compression ratio, whereas, the overall efficiency declined by 32.5%. A careful analysis of energy balance revealed excess energy loss to the coolant due to the existing combustion chamber design. Addressing the combustion chamber design for producer gas fuel should form a part of future work in improving the overall efficiency. 02lO1535 Biomass production of short-rotation bioen’ergy hardwood plantations affected by cover crops Malik, R.K. et al. Biomass and Eioenergy, 2001, 21, (1). 21-33. Effects of varying strip widths of four species of cover crops on the growth of sweetgum (Liquidamhar sryraciflua L.) seedlings planted as a short-rotation bioenergy woody crop were studied. Ryegrass (Lolium multiflorum L. a winter annual grass); tall fescue (Fesruca arundinacea Schreb a cool-season perennial grass); crimson clover (Trifolium incarnatum L. a winter annual legume); and Interstate sericea lespedeza 196 Fuel and Energy Abstracts May 2002