Objective Objectives and deliverables The acronym BIGTOE stands for Biomass Integrated Gas Turbine Operation Efficiency. The objectives of this study are to establish the optimum conditions under which a gasifier fed with a biomass fuel can be operated with the intention of producing the maximum quantity of gases of sufficiently high combustion quality for subsequent use to maximum effect as a fuel in an associated gas turbine in order to produce a power output. Rather than incur the expense of time and a considerable amount of money in designing, constructing and monitoring in a full-scale plant, the optimum conditions are being established through the use of sophisticated 3-dimensional mathematical modelling techniques for a universal gas turbine fired by an input fuel of which the characteristics have been identified from experiments undertaken using a pilot-scale gasifier. Both components of the technique have been well-validated in previous investigations and are being brought together in the BIGTOE project. In addition to the establishment of operating conditions in the gasifier for maximising gas yield from biomass fuel, there will be the need to reduce the emissions of nitrogen oxides (NOx) and trace elements (e.g. Na, K, Al, Cd and Fe2O3). The model that will be developed to simulate the combustion of a typical gas derived from a gasifier for use in the gas turbine will also incorporate an NOx emission model based on a simplified version of the numerous (120 or more) nitrogen chemistry reactions that occur during combustion. Operating parameters will then be varied to determine their effect on the emission and optimised to produce the lowest possible levels.In the BIGTOE project the Rankine (Steam ) cycle and the Brayton (Turbine) cycle are combined into an Integrated Gas Combined Cycle (IGCC) The chemical reactions that occur in the gasifier within this combined cycle are relatively simple. In the first of two steps the waste is thermally decomposed with air or oxygen, injected into the gasifier in order to provide the necessary heat. The product of this initial step is a gas with a low calorific value and a solid semi-coke residue. In order to further enhance the overall calorific value, the solid is then gasified with steam to produce CO and Hydrogen. A fluidised bed is being used to gasify to provide a uniform composition users of this technology, the fluidised bed has the advantage that low calorific feed stocks, such as biomass and waste, are readily assimilated into the process. These two technologies will be integrated through the art and craft of mathematical modelling. The simulated flow, combustion and thermal radiation in a universal turbine fired with the products from a pilot scale fluidised bed gasifier will be predicted. The mathematical code being used has already been applied to a combustor fired with the products of coal-gasification and validated against systematically collected experimental data. The runs with the biogas fuel will be simulated with the code with the aim of increasing the understanding of biomass combustion physics in a gas turbine. The operating parameters of the turbine will be varied in the mathematical code over a wide range and the relative effect of each on the performance and emissions, especially in regard to NOx, will be assessed. These studies will look at such changes as the orientation and position of dilution holes, the primary air momentum, the exit duct geometry and variations in the biogas fuel composition. At the same time, the main parameters governing the pyrolysis/gasification reactions in the fluidised bed gasifier will be identified. These include the operating conditions such as the temperature of the bed, the residence time of the biomass and the variation in the amount and pressure of steam that is introduced. Of equal importance will be a study of the quality, variation and origin of the biomass. Fields of science natural sciencesmathematicspure mathematicsgeometryengineering and technologyenvironmental engineeringenergy and fuelsagricultural sciencesagricultural biotechnologybiomassnatural scienceschemical sciencesnatural sciencesmathematicsapplied mathematicsmathematical model Programme(s) FP3-JOULE 2 - Specific research and technological development programme (EEC) in the field of non-nuclear energy, 1990-1994 Topic(s) 0303 - Biomass Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE EU contribution No data Address Exhibition Road SW7 2BX LONDON United Kingdom See on map Links Website Opens in new window Total cost No data Participants (2) Sort alphabetically Sort by EU Contribution Expand all Collapse all CINAR SA Greece EU contribution No data Address 4,H. Mexi Street 4 11528 ATHENS See on map Total cost No data NATIONAL LABORATORY FOR ENGINEERING AND INDUSTRIAL TECHNOLOGY Portugal EU contribution No data Address Estrada do Paco do Lumiar 22 1649-038 LISBOA See on map Total cost No data
