07 AltemaHve energy souses (bioconversion energy)

of electricity production using an improved steam cycle based on low energy gas and natural gas. At the same time the feasibility and the operability of a high temperature low energy gas cleaning is demonstrated on an industrial scale.

9amQ61 Options for biomass drying: What’s feasible? What’s practical? Turnbull, J. H. et al. BioenerRy ‘96, Proc. Natl. Bioeneqy Conf., 7th, 1996, 1, 557-564. Fuel drying can make an important difference in the energy balance of a power plant. Combustion efficiency decreases and the amount of flue gas passing through the boiler increases if the moisture content is high. Thus, if the fuel is dried before firing, some boiler components are smaller in a new plant, whereas for some existing boiler facilities, the steam generation can be increased. Fuel drying technologies are assessed and an inventory of high moisture feedstocks that would most benefit from drying is presented. Some interesting drying technology developments close to commercializa- tion are presented.

90to3082 Options for thermochemical processing of biomass Spath, P. and Tyndail, D. Proc. Biomass Conf. Am.: Energy, Environ., Agric. Ind., 2nd, 1995, 607-616. Transportation fuels and fuel additives such as methanol, mixed alcohols, hydrogen, ethers, gasoline, diesel and jet fuel can all be produced by thermochemical processing of biomass. These products are produced by technologies involving biomass gasification or pyrolysis. A synthesis gas consisting primarily of hydrogen, carbon monoxide, carbon dioxide and water is produced by gasification technology. This syngas can be used to make a wide range of products including alcohols, hydrogen and hydrocarbon fuels. Biomass pyrolysis technology produces high molecular weight pyrolysis vapours that can be converted into either a refinery feedstock or a thermobiodiesel product. At the National Renewable Energy Laboratory, stand alone biomass systems, as well as the integration of biomass thermochemical conversion technology with existing facilities, are being examined. Possibilities exist for integrating with petroleum refineries, natural gas-to-methanol plants, ethanol plants, coal gasification facilities and pulp and paper mills.

98lO3083 Overview of fast pyrolysis of biomass for the production of liquid fuels Diebold, J. P. and Bridgwater, A. V. Dev. Thermochem. Biomass Cowers., 1997, 1, S-23. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK. This work aims to provide a brief overview of the fast pyrolysis of biomass for the production of liquid fuels. The basic pertaining to the realization of fast pyrblysis in research, bench, and pilot scales are dkscribed. In addition, a description of the products and potential uses is included.

98/930&t Performance study of biomass gasification with oxygen-rich air Wu, C. et al. Taiyangneng Xuebao, 1997, 18, (3), 237-242. (In Chinese) The paper studies the performance of a circulating fluidized-bed gasifier for geneiaiing medium-hkating-value fuel gas by biomass gasific&ion with oxygen-rich air under varying oxygen concentration and equivalence ratio. Optimum operating conditions were determined; oxygen concentration was 85-90% and gasification equivalence ratio was 0.15. The process has advantages of small shell size and convenient control.

90lo3Qas Plans for the production and utilization of bio-oil from biomass fast pyrolysis Trebbi, G. et al. Dev. Thermochem. Biomass Comers., 1997, 1, 378-387. Edited by Bridgwater, A. V. and Boocock, D. G:B., Blackie, London, UK. The Thermal Research Centre of Pisa has realized a R&D plant for bio-oil production, through vegetable biomass flash pyrolysis process. Conducted in close collaboration with the Umbria Region. the oroiect is oartiallv financed by the EU. The plant has been ericted at (he ‘ENEL thermd- electric power plant of Bastard0 (Perugia). The process unit (RTP-rapid thermal processing) has been developed by the Canadian Ensyn Company, whereas ENEL has designed and constructed the auxiliarv facilities. With a caoacitv of orocessine 13 t/d of drv feedstock and 10 t/d-of liauid fuel. the &nt is the’largest 07 this type in’Europe. The technical chaiacteristics of the plant and the aims of the tests that will be performed with hardwood sawdust and other feedstocks are described. The iests are finalized to assess the techno-economic feasibility of the flash-pyrolysis process, a step necessary for the commercialization of the technology.

98lO3086 Potential contribution of the forest sector to carbon sequestration in Finland Pussinen, A. et al. Biomass and Bioenergy, 1997, 13, (6), 377-387. Increasing amounts of carbon have been sequestered by forests as the size of the total volume of the growing stock in Finland has grown since the mid- 1960s. The net sequestration by forests has also been substantial when compared with the CO2 emissions resulting from energy generation and consumption based on fossil fuels and peat. In mitigating the effects of climate change, it is important to assess how the sequestration capacity of forests may change under changing climatic conditions. This paper presents the results of a study assessing the development of the forest and wood- product carbon budget for Finland, based on regionally measured data, detailed dynamic models, and recent predictions concerning the changing

climate. At the starting point for the simulation (1990), nearly 90% of the forest sector’s carbon storage was found in the forest. Regular management transferred carbon from forests to wood products. Under the current climatic conditions, the simulated forest carbon storage increased 45% by the year 2100, and the wood-product storage by 320%. as a consequence of continuous production. Under changing climate conditions, the forest carbon storage increased, but started to decline when the temperature increase exceeded 2S”C within 40 years.

96m3087 Predicting sustainability of forest bioenergy pro- duction in the face of changing paradigms Kimmins, J. P. Biomass and Bioenergy, 1997, 13, (4/5), 201-212. Great environmental advantages of providing a renewable energy source and displacing fossil fuels are offered by short rotation, even-aged, monoculture, intensively managed bioenergy plantations, but they face a problem. They are increasingly at odds with the environmental movement’s paradigm of what forests should be: late succession, long rotation, uneven- aged. partially harvested, with retention of much of the net primary production as soil carbon. snags and coarse woody debris. International pressure to certify forests as being sustainably managed is having a major and generally positive effect on forests managed for conventional forest products. However, if this movement expands to encompass bioenergy forests, these alternative energy production systems will face new challenges. For example, how to maintain the efficiency of the systems while at the same time satisfying ‘criteria and indicators’ that are being established to define ‘sustainability’. Prediction methods for the sustain- ability of bioenergy systems are discussed and it is concluded that multi- value, ecologically-based ecosystem management models of the hybrid simulation type will be needed to design sustainable management systems that will satisfy the emerging set of criteria and indicators of sustainability. The second and third generation hybrid simulation models FORECAST and FORCEE, which had their origins in the FORCYTE models develooed specifically to evaluate the sus&nability of bioenergy plantations, are briefly reviewed. Strategies combining biological and technological approaches, which conserve soil organic matter and nutrients, and which utilize organic wastes, are expected to have the greatest chance of attaining sustainability.

98/03088 Pressurized combustion of biomass-derived, low caiorific value, fuel gas Andries, J. et al. Dev. Thermochem. Biomass Comers., 1997, 2, 1026-1030. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK. As part of the JOULE 3 programme, the EU partially funded a 3-year (1996-1998) project. Experimental and theoretical research has been done on the pressurized combustion of biomass-derived, LCV, fuel gas. European Gas Turbines Ltd will design, manufacture and supply a pressurized high temperature combustor for the biomass derived, LCV, fuel gas matched to the Delft gasifier. The combustor will be installed in the Delft test rig and experiments carried out to gather experimental data on the steady state and dynamic behaviour of the combustor. To simulate the steady state and dynamic behaviour of the combustor, mathematical models will be developed. The refined and validated steady state and dynamic combustor models will be used by European Gas Turbines Ltd to develop a gas turbine model which will be incorporated in a plant layout for an advanced biomass-fuelled IGCC plant. The project objectives, the intended test rig and the time schedule of the project are described.

98/03989 methods

Properties of fast pyrolysis liquids: status of test

Meier, D. et al. Dev. Thermochem. Biomass Cowers., 1997, 1, 391-408. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK.

9m3090 The pyrolytic decomposition and subsequent com- bustion of rice husks Connor, M. A. et al. Dev. Thermochem. Biomass Convers., 1997, 1, 67-81. Edited by Bridgwater, A. V. and Boocock, D. G. B., Blackie, London, UK. In many third world countries, waste rice husks are a potential, but often little-used fuel source. Rice husks contain up to 24% silica, in the form of a three-dimensional skeleton. It is therefore harder to achieve complete combustion compared to other, preferred fuels. More efficient rice husk combustion equipment design requires a better understanding of the pyrolytic and combustion steps in the overall combustion process. Fundamental studies of these steps have, to date, usually employed thermogravimetric techniques. However, work undertaken on the oxidation kinetics of crude oil suggested that an effluent gas analysis (EGA) technique could provide information both supplementary and complemen- tary to that obtained by thermogravimetry. This technique involves heating the material under study at a pre-set rate and gas with a known oxygen content is simultaneously passed through the material. The composition of the exit gas is measured. Rice husk was employed in a series of EGA experiments, which not only demonstrated the potential of the EGA approach as a means for learning more about biomass pyrolysis, but also provided insights into the effects of variations in pressure, oxygen partial pressure and particle size on rice husk combustion.

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