This ambitious project relates well to the diversified and complementary RTD expertises of the partners involved in the project, and their longstanding experience: development, design and operation of fluidized bed biomass gasification installations, hot gas filtration systems, catalytic reforming of tars, chemical hot gas cleaning, development and testing of solid oxide fuel cells, comprehensive modeling of heterogeneous reaction systems. A considerable number of partners have established a fruitful cooperation in previous European Contracts (JOR3-CT97-0196 and ENK5-CT2000-00314) aimed at a catalytic gasification process yielding a medium LHV syngas by means of a pilot scale application of the FICFB gasifier, at that time under development in Vienna, and at the efficient coupling of this gasifier with a molten carbonate fuel cell (MCFC), via hot gas cleaning; in this sense, the UNIQUE consortium is itself representative of the current state of the art in the production, from biomass, of high purity fuel gas for efficient power generation in a distributed production market. Consortium members include also the stakeholders relevant to assure the necessary impact for dissemination and exploitation of the results at industrial level, and to promote in the medium term practical applications for the commercialization of the innovation. Moreover, all work packages are linked to each other by the overall aim to integrate complementary process sections into one advanced hot gas cleaning and conditioning technology to be implemented in the biomass gasifier vessel, in order to increase process conversion efficiency in a cost effective way. Europe's energy system needs to be adapted into a more sustainable one, based on a diverse mix of energy sources, in particular renewables, and among them biomass; enhancing power generation efficiency; addressing the pressing challenges of security of supply and climate change, whilst increasing the competitiveness of Europe's industries. In contrast to the centralized power generation systems established for fossil energy sources, bio-energy is amenable to distributed (local) production and output, close to areas of biomass availability; this approach blends well with that of power market deregulation and power generation decentralization. This project is addressed to the quite broad field of power, and combined heat and power (CHP) from biomass, more specifically to the route of advanced biomass gasification systems, with the aim to increase overall conversion efficiency and cost efficiency, to drive down the cost of electricity. Biomass gasification is a thermo-chemical conversion process utilizing air, oxygen and/or steam as gasification agents, which produces a fuel gas rich in hydrogen and carbon monoxide, with a significant content of methane; carbon dioxide, steam and nitrogen are also present in the producer gas, in addition to organic (tar) and inorganic (H2S, HCl, NH3, alkali metals) impurities, and particulate. Biomass gasification plants have been realized and are operating in different European countries, demonstrating the development of the integration among gasification, gas cleaning, heat and power generation, and the potential of these technologies to contribute significantly to sustainable energy production both, in developed and developing countries. Gas cleaning is normally done by filtration and scrubbing of the producer gas, to drastically reduce particulate and tar content: in this way the clean gas is made available at temperatures close to ambient, and the most immediate option for power generation is gas engine. Such process configuration does not allow high electric conversion efficiencies: reported values are close to 25%, that is what is also obtainable with modern combustion plants coupled with steam turbines. This penalizes notably the overall economic balance of the plant, which would benefit of an higher share of electricity against heat production, due also to the incentives for green electricity offered in most countries. In addition, tar separation is sometimes not as effective as it should be, reduces the gas yield, originates waste streams difficult to dispose or recycle properly. It is worth mentioning here that complications in the plant scheme originated by gas treatments required to obtain a tar-free product often contribute significantly to the overall investment and operating cost. This is even more negative when it is considered that small- to medium-scale gasification plants would fit optimally with the economic context of most regions, for a number of reasons ranging from the biomass transportation cost (biomass is a dilute energy source in comparison with fossil sources), to the need to establish a distributed power generation system, to scarce social acceptability of large thermal conversion plants. As a result, process simplification and intensification could play a very important role towards a real breakthrough in the utilization of biomass in general, and specifically of gasification plants. The detailed scientific and technical objectives and the major points of innovation characterising this RTD project against the present state of the art can be summarised as follows:

• Development of an innovative catalytic system for in-bed primary reduction of heavy hydrocarbons. In comparison with previously obtained Ni/olivine catalysts, this very low-cost material will remove completely the problem of heavy metals in the ashes to be disposed, and will assure similar reforming activity.



• Optimization of tar reforming catalytic filter elements, by screening new catalyst supports on laboratory scale, with regard to the adjustment of a high BET surface area at high temperature, by studying the catalytic activation process, and producing a high-performance catalyst system.



• Scale-up of the whole procedure to allow the manufacture of commercial-size catalytic candles, with characterized filtration properties.



• Choice and characterization of synthetic sorbents to be added properly to the gasifier to trap sulphur compounds and additional, detrimental trace elements in order to reduce their content in the hot gas to values compatible with downstream units, e.g. a high temperature fuel cell.



• Experimental check of the feasibility of the integrated arrangement proposed for the gasification reactor, and quantification of the performance of the gas conditioning and cleaning system at real process conditions, by means of a thorough test campaign at bench scale, in a bubbling fluidized bed gasifier with nominal load of 1 kg/h of biomass feedstock.



• Experimental check of the novel catalyst and the synthetic sorbents in the 100 kWth FICFB (dual fluidized bed steam blown biomass gasifier) pilot plant (Vienna Univ. of Technology).



• An industrial-scale benchmark of the effectiveness of the gas cleaning and conditioning system. This will be obtained by housing a couple of catalytic filter candles inside a commercial gasifier (Güssing plant, 8 MWth), to compare the producer gas quality in the slip stream passing through the innovative conditioning system, with that of the existing low temperature gas filtering and scrubbing system. Long duration tests to study aging or other time depending effects.



• Operation of a pilot scale unit (1 MWth) designed according to the principles illustrated above. Its realisation will be done by modifying the freeboard of an existing oxygen/steam, bubbling bed gasifier, in order to insert the candles needed for particulate filtration and tar reforming.



• "On-site" feasibility check of feeding the clean fuel gas finally obtained to a high efficient power generation system, by means of a bench scale, solid oxide fuel cell. As a result of laboratory work, a portable SOFC unit, suitable for tests with the producer gas on its anode side, will be assembled and arranged to be connected to a slip stream of the commercial and pilot scale gasifier, respectively.



• Modelling studies at different scales. Simulation of the complex heterogeneous reacting system inside the filtering medium, at contact times typically shorter than one second: catalytic reactions are favored by relatively low velocities in the filter and the influence of fine structure of the porous material for optimal operation needs to be studied in details, as well as that of a large pore size, characterizing the filter material, which on one hand reduces mass transfer limitations, on the other hand reduces also the specific active surface. CFD studies of the reactor freeboard, to optimise candles configuration in it. Process simulations of the whole energy conversion chain, to characterise the process flow-sheet and its overall thermal and chemical efficiency.