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Dynamic pressure measurements are introduced as a powerful tool to detected filter failures at early stage. Filter failures such as leakages and blockages can be detected during back pressure recleaning pulses. High frequency sensors enable the recording of the recleaning pressure pulse. Patchy cleaning and depth filtration can be detected much faster with dynamic pressure measurements than with differential pressure measurements. Parameters derived from dynamic pressure data can be observed over time and compared with reference data. The method complements conventional pressure difference measurements and is applied at a hot gas filter that implements coupled pressure pulse (CPP) technology. Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 837-843

With an increasing share of regenerative wind and solar energy in electricity supply, the aspect of load flexibility will gain importance, i.e. there is an increasing need for buffer capacities and / or power plants must be able to react more flexibly to changes of the demand. As an alternative or in addition to the new construction of peak­load power plants (pump storage systems, gas power plants), load-flexible dust burner technologies can be used in existing incinerators to increase the load flexibility and the fuel flexibility when using especially local regenerative fuel sources. Flexibility of the burner concept means an increase in changing fuel composition and non-stationary operation, which may cause changes of the combustion behavior and, hence, of the emission behavior. Flexibility in fuel sources changes the combustion and emission behavior, too, especially with regard to low rank fuels with high ash contents containing chlorine and alkali species. To control these non-stationary processes in the burner and downstream boiler area for an efficient operation, contact-free optical measurement methods are applied in addition to the measurement systems existing in the furnace chamber and furthermore control methods based on computational intelligence. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 1334-1337

Biomass-based pyrolysis oils are complex mixtures of mainly organic compounds and water. The determination of their physical and chemical properties and chemical composition is a challenge for researchers. Characterisation of biomass pyrolysis oils has been studied at many universities in North America and Europe in the 1980s and 1990s. The existing literature on the analytical methods used for these oils is reviewed in this report. The physico-chemical properties, such as water content, acidity, density, viscosity, heating value and stability, are important in terms of utilisation, storage and handling of oils. In the analyses, standard methods as such or as modified and, in addition, self-developed methods have been used. Standard fuel oil analyses are not often suitable as such for biomass-based pyrolysis oils. For characterising the chemical composition, the bio-oils have first been mainly fractionated into different classes. Solvent extraction and adsorption chromatography are the most general methods used. In solvent extraction, the oils have often been divided into acidic, phenolic, basic, hydrocarbon and aqueous fractions or water-soluble and -insoluble fractions. In adsorption chromatography, the oils have been fractionated into different hydrocarbon and polar fractions. The fractions obtained have been analysed with various chromatographic and spectroscopic methods. Gas chromatography/mass spectrometry (GC/MS) technique is the analytical method most widely used and well adaptable for the fractions. For high-molecular-mass and highly polar compounds liquid chromatographic (LC) techniques as well as infrared (FT-IR) and nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopies are more suitable due to the low volatility of pyrolysis oils. For whole pyrolysis oils, LC techniques, primarily size exclusion chromatography and FT-IR and FT-NMR spectroscopies have proved to be useful methods, giving information on molecular weight, functional groups and aliphatic and aromatic structures and ratios. Direct mass spectrometric techniques (MS), such as molecular-beam MS and MS/MS, are rapid and interesting tools for the characterisation of the oils and for the investigation of the pyrolysis process. In-depth characterisation of the complicated organic composition of pyrolysis oils requires the use of various techniques. The oils contain organic compounds such as acids, aldehydes, anhydrosugars, alcohols, phenolic compounds, esters and hydrocarbons, and, in addition, high-molecular, apparently lignin-derived substances, depending on feedstock, process conditions and recovery techniques.

The objective of this study is to determine analytically the actual potential of large-scale biomass-based electricity production technologies in the mid-term future in a large geographical area.A case study over a ten-year period was carried out for the United States state-by-state analysing potentials of commercial large power generation using fluidised bed technology.The time period is chosen to be consistent with the commitments of the Kyoto Protocol on greenhouse gas emissions.Technologies considered are (1) cofiring (CF) of biomass in existing coal fired power plants, (2) a new fluidised bed boiler for cofiring, (3) conversion of an existing boiler to fluidised bed combustion (FBC) and (4) an atmospheric biomass gasifier connected to existing boiler. All the concepts have been demonstrated and are in the commercial operation in Europe but their poor competitiveness has prevented a significant market penetration to date in the United States.Additionally, a novel concept of integra ting a flash pyrolysis unit to a fluidised bed boiler is evaluated.Cogeneration is also included in the study.Mill residues and municipal wood waste from construction, demolition and yard trimmings are the most low-cost fuels and they could generate in cofiring the electricity production capacity of 2000 MW and 8000 MW respectively.Agricultural and logging residues have large potential of 19000 MW and 6000 MW, but their costs are not so competitive.Dedicated energy crops and residues from silvicultural operations could manifold available resources in the future.Cofiring is the lowest-cost alternative for utilities to start use of biomass.Tax credits for cofiring during five years would make use of biomass in coal-fired boilers competitive 2000 MW with 0.5-cent/kWh-tax credit and 6000 MW with 1.0 cent/kWh.The willingness to invest is estimated to be small without obligations or high tax credits, because risks are large compared to benefits.FBC technologies are feasible if low-cost, low - quality fuels are available, SO2 or NOx emissions have been reduced, or boilers need repowering.A tax credit of 1.5 cent/kWh for 10 years would crate economic prerequisites for 8000 MW of atmospheric gasifiers and FBC boilers.Renewable portfolio standard (RPS) with a price level of 25 USD/MWh of renewable energy would create possibilities for the generation of 8000 MW by biomass, and with price level of 40 USD/MWh over 30 000 MW, and the probability of investments is estimated to be high.Possibility to increase cogeneration with very high over-all efficiencies in the forest industry is about 5000 MW, but special incentives for cogeneration would be needed.Tax credits could create active fuel markets for biomass and reliability of concepts could be tested, and learning curves would reduce investment costs.RPS-type of incentives would ensure the increase of renewable energy with a certain amount very effectively because operators are free to choose the most cost-effective measures for th em.Increase of the biomass-based electricity production could be 5% of the electricity demand and reduce 3% of CO2 emissions by 2010 based on low-cost biomass residues.