In large scale industrial processes, such as iron production, or in gasification based process chains (coal/biomass to synthesis gas, fuel, or power, etc.), the separation of CO2 (Carbon Capture-CC) can lead to ecological and procedural benefits. Chemical absorption of CO2 is a well proved technology for CC with comparatively low electrical energy demand. However, the high heat demand, absorption kinetics, CO2 capacity and sorbent degradation are limiting factors for the industrial application. Further investigation and development of sorbent-solutions in relation to specific gas conditions are necessary for optimisation. For testing different sorbent-solutions a mobile test plant was designed and built up. Focus of this work was the evaluation of process key data for CC in blast furnace gas under real conditions. The tests have been carried out continuously up to 300 hours. Aqueous monoethanol-amine (MEA), diethanol-amine (DEA) and methyl-diethanol-amine (MDEA) solutions have been investigated. Detailed analyses of the process gas, analyses of used liquids (chemical properties, degradation products) and the examination of process data lead to further development in process design, control strategies for specific applications and give routes for an efficient implementation of CC to increase the benefit in the overall process chain.

Global trade of biomass-related products is growing exponentially, resulting in increasing 'teleconnections' between producing and consuming regions. Sustainable management of the earth's lands requires indicators to monitor these connections across regions and scales. The 'embodied human appropriation of NPP' (eHANPP) allows one to consistently attribute the HANPP resulting from production chains to consumers. HANPP is the sum of land-use induced NPP changes and biomass harvest. We present the first national-level assessment of embodied HANPP related to agriculture based on a calculation using bilateral trade matrices. The dataset allows (1) the tracing of the biomass-based products consumed in Austria in the year 2000 to their countries of origin and quantifying the HANPP caused in production, and (2) the assigning of the national-level HANPP on Austria's territory to the consumers of the products on the national level. The dataset is constructed along a consistent system boundary between society and ecosystems and can be used to assess Austria's physical trade balance in terms of eHANPP. Austria's eHANPP-trade balance is slightly negative (imports are larger than exports); import and export flows are large in relation to national HANPP. Our findings show how the eHANPP approach can be used for quantifying and mapping the teleconnections related to a nation's biomass metabolism. © 2012 Elsevier B.V.

Because of the limited resources of fossil fuels the efficient use of renewable energy is gaining importance. Renewable energy from biomass reduces CO2 emissions, which is a necessity to protect the global climate. In the dual fluidised bed steam gasifier wood chips are converted to heat, power and other products very successfully. This work presents alternative feedstocks for this process: biomass wastes, such as waste wood, bark and reed. Waste wood and bark have been gasified successfully and first results of these experiments in the pilot plant are presented in this paper. It has been assessed that reed is also an interesting feedstock suitable for the use in fluidised bed gasifiers.

The increasing demand for biomass fuels leads to the introduction of new biomass fuels into the market. These new biomass fuels (e.g., wastes and residues from agriculture and the food industry, short rotation coppices, and energy crops) are usually not well-defined regarding their combustion behavior. Therefore, fuel characterization methods with a special focus on combustion-related problems (gaseous NO_x, HCl, and SO_x emissions, ash-melting behavior, and PM emissions) have to be developed. For this purpose, fuel indexes are an interesting option. Fuel indexes are derived from chemical fuel analyses and are checked and evaluated regarding their applicability by measurements performed at lab- and real-scale combustion plants for a large variety of fuels. They provide the possibilities for a pre-evaluation of combustion-relevant problems that may arise from the use of a new biomass fuel. A possible relation to describe the corrosion risk is, for instance, the molar 2S/Cl ratio. The N content in the fuel is an indicator for NO_x emissions, and the sum of the concentrations of K, Na, Zn, and Pb in the fuel can give a prediction of the aerosol emissions, whereas the molar (K + Na)/[x(2S + Cl)] ratio provides a first indication regarding the potential for gaseous HCl and SO_x emissions. The molar Si/K ratio can supply information about the K release from the fuel to the gas phase. The molar Si/(Ca + Mg) ratio can give indications regarding the ash-melting temperatures for P-poor fuels. For P-rich fuels, the (Si + P + K)/(Ca + Mg) ratio can be used for the same purpose. The fuel indexes mentioned can provide a first pre-evaluation of combustion-relevant properties of biomass fuels. Therefore, time-consuming and expensive combustion tests can partly be saved. The indexes mentioned are especially developed for grate combustion plants, because interactions of the bed material possible in fluidized-bed combustion systems are not considered.

Global climate change will make it necessary to transform transportation and mobility away from what we know now towards a sustainable, flexible, and dynamic sector. A severe reduction of fossil-based CO₂ emissions in all energy-consuming sectors will be necessary to keep global warming below 2 °C above preindustrial levels. Thus, long-distance transportation will have to increase the share of renewable fuel consumed until alternative powertrains are ready to step in. Additionally, it is predicted that the share of renewables in the power generation sector grows worldwide. Thus, the need to store the excess electricity produced by fluctuating renewable sources is going to grow alike. The “Winddiesel” technology enables the integrative use of excess electricity combined with biomass-based fuel production. Surplus electricity can be converted to H₂ via electrolysis in a first step. The fluctuating H₂ source is combined with biomass-derived CO-rich syngas from gasification of lignocellulosic feedstock. Fischer-Tropsch synthesis converts the syngas to renewable hydrocarbons. This research article summarizes the experiments performed and presents new insights regarding the effects of load changes on the Fischer-Tropsch synthesis. Long-term campaigns were carried out, and performance-indicating parameters such as per-pass CO conversion, product distribution, and productivity were evaluated. The experiments showed that integrating renewable H₂ into a biomass-to-liquid Fischer-Tropsch concept could increase the productivity while product distribution remains almost the same. Furthermore, the economic assessment performed indicates good preconditions towards commercialization of the proposed system.

Fischer-Tropsch (FT) synthesis is one option to produce liquid transportation fuels from carbon-containing feedstocks. In the past, FT synthesis was used mainly to convert coal or natural gas to diesel and gasoline. In the last decade, much R&D effort has been made to use this technology to convert biomass to a high-quality transportation fuel. In this chapter, the technology for BtL (conversion of biomass to liquid transportation fuels over FT synthesis) is described, from synthesis gas production including requirements on the gas quality to a detailed description of the FT synthesis itself. The main focus of this chapter is to give an overview of the types of catalysts, also including their preparation, reduction, and aging; the types of FT reactors; and also the reaction conditions including kinetic laws and mechanistic proposals.

The global warming, the increasing CO2 emission, the combustion and dependency on fossil fuels, as well as the high-energy prices have resulted in an increasing demand in renewable energy sources. Biomass, as a renewable energy source, has the potential to contribute to the future energy mix in many countries. In this thesis the so-called low temperature or slow pyrolysis is chosen to convert biomass into energy rich products. Pyrolysis is a process to convert biomass directly into solid, liquid and gaseous products by thermal decomposition in absence of oxygen. The goal of the pilot plant Dürnrohr is to generate a combustible gas to substitute fossil fuels in the thermal power plant Dürnrohr. The complete process consists of individual steps. First of all the biomass is pyrolysed and pyrolysis gas and pyrolysis char are produced. The obtained pyrolysis gas is combusted in a fluidized bed combustion chamber implemented as afterburner. The following step is fluidized bed combustion of
the intermediate-stored pyrolysis char. Due to the use of different biomasses and adjustment of the individual steps, the process should be optimized for the application for the power plant Dürnrohr. One major point of the production of the pyrolysis gas is the amount of tar. The tar amount was analyzed during pyrolysis operation to find out how much tar is produced at which process settings with a main focus on the temperature. The gravimetric
analysis included gravimetric tar, dust, entrained char, water content and ph-value, as well as the GC/MS tars of the pyrolysis gas. All these data was sampled, analyzed and evaluated as well as discussed.

This study aims to determine the fate of P during fluidized bed co-combustion of chicken litter (CL) with K-rich fuels [e.g., wheat straw (WS)] and Ca-rich fuels (bark). The effect of fuel blending on phosphate speciation in ash was investigated. This was performed by chemical characterization of ash fractions to determine which phosphate compounds had formed and identify plausible ash transformation reactions for P. The ash fractions were produced in combustion experiments using CL and fuel blends with 30% CL and WS or bark (B) at 790–810 °C in a 5 kW laboratory-scale bubbling fluidized bed. Potassium feldspar was used as the bed material. Bed ash particles, cyclone ash, and particulate matter (PM) were collected and subjected to chemical analysis with scanning electron microscopy–energy-dispersive X-ray spectrometry (SEM–EDS) and X-ray diffraction. P was detected in coarse ash fractions only, that is, bed ash, cyclone ash, and coarse PM fraction (>1 μm); no P could be detected in the fine PM fraction (<1 μm). SEM–EDS analysis showed that P was mainly present in K–Ca–P-rich areas for pure CL as well as in the ashes from the fuel blends of CL with WS or B. In the WS blend, P was found together with Si in these areas. The crystalline compound containing P was hydroxyapatite in all cases as well as whitlockite in the cases of pure CL and WS blend, of which the latter compound has been previously identified as a promising plant nutrient. The ash fractions from CL and bark blend only contained P in hydroxyapatite. Co-combustion of CL together with WS appears to be promising for P recovery, and ashes with this composition could be further studied in plant growth experiments

Zum Erreichen der Ziele der österreichischen Klimastrategie leisten Biomassefeuerungen einen entscheidenden Beitrag. Um dabei die Luftgüte nicht außer Acht zu lassen, wird in diesem Factsheet der aktuelle und zukünftige Status (bis 2050) von Staubemissionen in Österreich basierend auf Literaturdaten und eigenen Messungen dargelegt, und der aktuelle Kenntnisstand zu Emissionen aus Biomasse-Kleinfeuerungen zusammengefasst.

There is a need to reduce NO_x emissions, which can only be achieved through a detailed understanding of the mechanisms for their formation and reduction. In this work the release of the NO_x precursors, NH₃ and HCN, for different fuels is experimentally analysed and modelled in typical fixed-bed combustion conditions. It is shown that NH₃ and HCN are released during the main devolatilization phase and the NH₃/HCN ratio increases for fuels with a higher nitrogen content. A simplified two-steps model for their release is presented. The model can predict with a reasonable accuracy the release for fuels with a low nitrogen content, however deviations are present for fuels with a high nitrogen content, which probably arise due to a reduction of NH₃ and HCN taking place already in the bed.