Synthesis gas from biomass can be produced and utilized in different ways. Conversion of biomass to synthesis gas can be done either in fluidized bed or entrained flow reactors. As gasification agent oxygen, steam, or mixtures are used. The most common use of biomass gasification in the last decades has been for heat and/or power production. Nowadays, the importance of transportation fuels from renewables is increased due to environmental aspects and growing fossil fuels prices. That is why the production of Fischer-Tropsch (FT) liquids, methanol, mixed alcohols, substitute natural gas (SNG), and hydrogen from biomass is now in focus of view. The most innovative and interesting ways of synthesis gas utilization and projects, BioTfueL or GoBiGas, BioLiq, Choren, etc. are discussed here. Further the microchannel technology by Oxford Catalysts and distributed production of SNG in decentral small scale are presented. The synthesis platform in Güssing, Austria is also presented. The FT liquids, hydrogen production, mixed alcohols, and BioSNG, these are the projects associated with the FICFB gasification plant in Güssing. Also the principle and examples of sorption-enhanced reforming to adjust H₂/CO ratio in product gas during the gasification is described. Finally, in the conclusion also an outlook for the thermochemical pathway to transportation fuels is given. WIREs Energy Environ 2014, 3:343-362. doi: 10.1002/wene.97 For further resources related to this article, please visit the WIREs website. © 2013 Wiley Periodicals, Inc.

Trace nutrients significantly affect the microbial metabolic activity within anaerobic digestion processes but always imply the risk of overdosing of heavy metals. In this study the applicability of a sequential extraction scheme established for soil and sediment samples on biogas slurries with different compositions was tested and compared to an adapted version of this extraction method. The analytical results proved the successful applicability of the developed analytical technique for the speciation of trace nutrients in anaerobic digestion systems. The procedure fulfills the basic requirements of reproducible data, a time-saving analytical approach and economic feasibility. Recovery rates of 90-110% were obtained for the most important trace elements Fe, Co, Cu, Mo, Ni and Zn. However, it was demonstrated that the adapted method provides more reliable information about the bioavailable fractions and it is considered the more appropriate approach. Data on fractionation indicated that up to 76% of these essential trace nutrients might be present in an insoluble state. Depending on the specific trace element a significant fraction, from 30% to more than 70%, is not directly bioavailable. This important aspect should be considered to guarantee sufficient supply of the microbial consortium with trace elements and at the same time to avoid overdosage. © 2014 Elsevier Ltd.

The production of higher alcohols over a sulfidized molybdenum catalyst (MoS₂) using a biomass-derived synthesis gas has been studied at Güssing for several years. The mixed alcohol (MA) pilot plant uses synthesis gas provided by the biomass-based combined heat and power plant (CHP) Güssing. Parameter variations were carried out wherein temperature, space velocity and gas composition were varied to evaluate the impact on CO conversion, product distribution and yield. The influence of side reactions to hydrocarbons was also a research objective. A sufficient amount of experimental data was obtained during these experiments. Evidence for the influence of various reaction parameters was found, but the mass balance could not be closed. A mathematical model of the MA synthesis reactor was developed using the stationary equation-orientated flow sheet simulation software IPSE_pro. This publication gives an overview of modeling the MA reactor and condenser unit and testing the model with example calculations. Validated experimental results from 2012 parameter variation are shown and a comparison between experimental and validated quantities is carried out. A comparison with literature data shows that the observed tendencies are in good correlation to literature. The developed reactor model was enabling the possibility for carrying out a validation of the experimental data. IPSE_pro uses the method of least-squares to obtain the approximate solution of the overall determined system. The established model was very close to the actual MA pilot plant. The model is very accurate about MA liquid product compositions and all measured flows.

A novel hybrid gas phase combustion model suitable for low as well as high turbulent combustion conditions is proposed. In particular, in the region above the fuel bed of small-scale biomass combustion plants, gas phase mixing is highly influenced by laminar and low turbulence zones. Here, the eddy break-up combustion models are not valid because they were originally developed for highly turbulent flows. Therefore, a CFD gas phase reaction model applicable over the whole Reynolds range from laminar to turbulent flows is developed. It is a hybrid Eddy Dissipation Concept/finite rate kinetics model which calculates the effective reaction rate from laminar finite rate kinetics and the turbulent reaction rate and weights them depending on the local turbulent Reynolds number of the flow. To validate the proposed model, comparisons are made with experimental data for a series of jet flames covering laminar, transitional, and turbulent flow conditions. The simulation results show that the prediction of flame can be improved with the proposed hybrid combustion model. © 2014 Elsevier Ltd. All rights reserved.

Since batch-wise operated biomass roomheaters are claimed to cause high amounts of gaseous and particulate emissions effective measures for a reduction of these emissions especially in real life operation have to be implemented in the future. For a verification of the real life operation performance as well as for a better product differentiation of biomass room heating appliances on the market advanced testing methods will be necessary in the future. Therefore a new test method for roomheaters called “Stove Testing 2020” (ST2020) was developed. According to the new test method the emission and efficiency performance of roomheaters is determined under operating conditions that are closer to real life. Compared to the existing EN 13240 standard also transient combustion phases are included. For a final evaluation of the test method the reproducibility as well as the real life relevance was analysed by a Round-Robin-Test as well as by field tests. The results showed sufficient reproducibility as well as a high real life relevance of the ST2020 test method. However, due to the strong impact of user behavior on emission and efficiency performance in real life operation further technological improvements of biomass roomheaters have to be strongly supported by effective measures to guarantee a correct operation.

Microalgae are seen worldwide as a new and promising feedstock for the energy supply chain.
Because of their high productivity and their ability to convert CO2 into biomass, microalgae are a
potential raw material for biorefineries, avoiding the food versus fuel conflict, and contributing to an
increased share of renewable energy. According to the current state of the art the utilization of algal
biomass for the production of fuel, energy and heat seems to be economically not competitive and the
life cycle assessment shows improvement possibilities in energy consumption (project
Algae&Energy:Austria). There are different options for utilization concepts which are technologically
and economically feasible. New concepts need to be developed and synergies with already existing
technologies need to be used.
Challenges along the value chain:
· Supply of water for cultivation
· Supply of nutrients for cultivation
· Energy consumption during cultivation
· Harvesting and processing of biomass
· Investment and operating costs
One possibility to cover the need of water and nutrients in a cost-effective way is the combination of
microalgae cultivation and waste water treatment. The cultivation of algae using different waste water
types common in Austria is technologically possible. In particular municipal waste water and effluents
from breweries and dairies are suitable as substrate. Due to the usage of this synergy the need for
fresh water and artificial fertilizer for algae cultivation decreases substantially and therefore operating
costs are reduced. Promising production concepts were developed and further research and
development needs were pointed out (project SAM).
After producing algal biomass the harvesting and processing steps for further utilization seem to be
difficult. In particular the high amount of water increases the energy expenditure in most of the
conversion pathways. Hydrothermal liquefaction seems to be promising to reduce the energy intensity
through two major factors: First, the conversion takes place in the liquid phase, and no energy
intensive drying of the algal biomass is needed. Second, the entire carbon which is fixed in the algae
can be used for energy production. The main product of hydrothermal liquefaction is a bio-oil, which
can be further processed in existing refinery processes into biogenic motor fuels, plastics and basic
chemicals (project microHTL).
In Austria many scientific research groups and companies are dealing with microalgae in the energy
system. These research and development efforts comprise different topics and approaches, like
different cultivation system designs (open pond, photobioreactor), biotechnological optimization of
microalgae species, the utilization of algal biomass in energetic and material pathways or the
combination of microalgae cultivation with existing technologies. It is of growing importance to
establish a network of Austrian experts and research groups for enhancement of cooperation and
research within the field of algae (project network biobased industry).
Through the optimization along the entire value chain with special regard to novel concepts of
cultivation, harvesting, processing, conversion and utilization, as well as an enhanced network of
Austrian experts and research groups, microalgae can serve as biogenic feedstock for the energy

Three mono-digestion experiments treating slaughterhouse waste with high TKN concentration (~11. g/kg) were applied in lab-scale at mesophilic and psychrophilic conditions to study the impact of high ammonia concentrations and additives. Precipitation of sulphur by addition of ferrous chloride did not influence process behaviour, whereas supplementation of trace elements significantly improved process stability by reducing volatile fatty acid concentration towards zero.The limit of NH₄-N concentration causing a rise of VFAs to 19,000mg/l and reduction of methane by 25% was found between 7.7 and 9.1g/kg which correspond to NH₃ concentrations of 830-1060mg/l.Psychrophilic operation (25°C) lowered inhibitory NH₃ concentration to 140mg/l, but process performance was stable only at low OLR of 0.4kgVS/m³d.Robust performance at highest possible NH₄-N concentration (7.7g/kg), low VFA accumulation and satisfying methane yield of about 280Nm3/t COD was observed at OLR of 2.5kgVS/m³d at 37°C. © 2014 Elsevier Ltd.

The current debate on biomass price volatility mainly refers to increased market dynamics and integration as well as renewable energy policy intervention. Higher price volatility leads to additional costs that are often transmitted along the supply chain to the final consumers. We empirically analyze whether or not price volatility of woody biomass commodities has increased in recent years. Results indicate that the price volatility of some woody biomass
commodities has increased, but it is still lower than of fossil fuels.

Producer gas from biomass gasification contains mainly hydrogen, carbon dioxide, carbon monoxide, methane and some other low molecular hydrocarbons like propylene. This paper reports mathematical simulation and experimental study of steam reforming of methane mixture with propylene in a packed bed reactor filled with nickel based catalysts. Due to the high heat input through the reformer tube wall and the endothermic reforming reactions, a two-dimensional pseudo-heterogeneous model that takes into account the diffusion reaction phenomena in gas phase as well as inside the catalyst particles has been used to represent temperature distribution and species concentration within the reactor. Steam reforming of propylene is faster and more selective than methane and it is shown that addition of propylene to the methane steam mixture reduces the conversion of methane. The obtained results play a key role in optimization and design of a commercial reactor. © 2014 Elsevier Ltd. All rights reserved.