Benjamin Mast

Characterization of different biomasses based on their sugar profile with focus on their utilization for microbial biodiesel production.

The investigation and characterization of different biomasses as potential feedstocks for microbial lipid production was the aim of the present work. Twenty-eight biomasses were analyzed for total sugar content (glucose and xylose) and C/N-ratio as two major criteria for a suitable lipid production by oleaginous microorganisms. Considering both parameters, 9 out of 28 biomasses seemed to be suitable feedstocks for microbial lipid production. To allow for a broad evaluation of the suitability of the potential feedstocks, the estimated sugar and potential energy yield per area were calculated and the production costs and energy demand of the feedstock production were considered.

Bioenergy for regions - alternative cropping systems and optimisation of local heat supply.

In the frame of a research project for the energy supplier “Energie BadenWürttemberg AG” (EnBW) in Germany, the aim of the study is to evaluate the potentials of alternative substrates and their viability for biogas conversion based on current production regimes in the county of Biberach in the South-West of Germany. The project includes 5-yr field tests of optimized cropping systems leading to higher biodiversity and sustainability while ensuring a constant biomass supply for biogas production. Furthermore precise calculations and estimations of the heat demand of rural areas have been made on an object-based level (residential and tertiary/industry) using a geographic information system (GIS). On the basis of existing biogas plants, techno-economical analysis of heat and micro gas networks have been performed. Sustainability is mainly emphasized on the basis of the aspect of environmental influence on cropping systems (biodiversity, soil erosion, ground and surface water pollution). Biogas yield data at laboratory scale are used to evaluate the economy of alternative cropping systems with regard to energy production as compared to the reference (maize monoculture) in the whole chain ranging from field cultivation to energy use. The practical feasibility and the environmental effects are reviewed in comprehensive and multi-field tests and field trials.

Acrylamide Formation Potential of Organically and Conventionally Grown Cereals

As bakery products contribute considerably to the daily intake of the carcinogen acting substance acrylamide (AA), the aim of this study was to evaluate the impact of the cropping system (conventional vs. organic farming) on AA precursor levels of free asparagine (Asn) across different cultivars of the cereal species, namely winter wheat (Triticum aestivum), winter spelt (Triticum aestivum ssp. spelta) and winter rye (Secale cereale) with simultaneous consideration of gained grain yields and flour qualities. For this purpose, orthogonal field trials were established at two sites in Southwest Germany over two growing seasons (2006-2007 and 2007-2008). The results indicated a significant impact of the cropping system on free Asn contents. Across all species, free Asn contents in the flour were 26 % lower under organic compared to conventional farming. The impact of the cropping system on individual cultivars was obvious with a maximum reduction in free Asn contents of 50 % (e.g. for cultivars Ludwig, Privileg, Capo) if organically produced. For spelt, a significant impact of the cropping system was only found in 2008 with a reduction in free Asn of up to 25 % if organically produced. Across both cropping systems, cultivar Franckenkorn reached the lowest levels of free Asn. For rye, a significant impact of the cropping system was observed only in 2007 with 33 % higher Asn amounts in the conventional cropping system. Independent of the cropping system, rye reached the highest levels of free Asn followed by wheat and spelt. Across both cropping systems, species and cultivars, the amount of free Asn correlated with the AA content in heated flour with R2=0.63***. Furthermore, the results indicated that lower AA contents in bakery products can be achieved by proper selection of species (e.g. 66 % lower if rye is replaced by wheat) and cultivars. With an appropriate choice of the cultivar, a reduction of up to 65 % was possible within wheat, along with a reduction of 44 % within spelt and 12.5 % within rye. In summary, the results indicated that organically produced wheat especially offers the opportunity to significantly lower the AA potential of bread and bread rolls by the choice of raw materials low in free Asn.

Bioenergy For Regions: Alternative Cropping Systems And Optimisation Of Local Heat Supply

In the frame of a research project for the energy supplier “Energie BadenWurttemberg AG” (EnBW) in Germany, the aim of the study is to evaluate the potentials of alternative substrates and their viability for biogas conversion based on current production regimes in the county of Biberach in the South-West of Germany. The project includes 5-yr field tests of optimized cropping systems leading to higher biodiversity and sustainability while ensuring a constant biomass supply for biogas production. Furthermore precise calculations and estimations of the heat demand of rural areas have been made on an object-based level (residential and tertiary/industry) using a geographic information system (GIS). On the basis of existing biogas plants, techno-economical analysis of heat and micro gas networks have been performed. Sustainability is mainly emphasized on the basis of the aspect of environmental influence on cropping systems (biodiversity, soil erosion, ground and surface water pollution). Biogas yield data at laboratory scale are used to evaluate the economy of alternative cropping systems with regard to energy production as compared to the reference (maize monoculture) in the whole chain ranging from field cultivation to energy use. The practical feasibility and the environmental effects are reviewed in