Integrated systems for bioenergy and agriculture in a future without fossil resources (BioCulture)
Synergies emerge when integrating bioenergy production and the agricultural industry. The integration ensures a potential for a very efficient and flexible energy system that moreover recovers valuable and potentially scarce nutrients and carbon to maintain soil fertility and soil carbon sequestration. Developing and analyzing specific energy system concepts of possible integrations of bioenergy and agriculture are needed to explore and map the most efficient integrations. Together with communication to relevant stakeholders, the energy system analyses should push the development towards optimal utilization of valuable resources.
Bregentved Estate is one of Europe’s largest agricultural businesses and because of its strategic interests in a sustainable business of food and energy production, Bregentved Estate has developed an overall concept for a combined energy and agriculture system in a future without fossil resource consumption. The concept is called Bregentved CleanTech System.
Based on the overall Bregentved CleanTech System, we will determine specific energy system concepts for further investigation. A well-structured definition of relevant concept ideas followed by a generation and selection of key system concepts will be completed. The aim is to limit the number of specific system concepts, which will undergo a thorough analysis and assessment. Further investigation of the selected key energy system concepts will be conducted using simulation models to do system analyses. The best performing systems will undergo an assessment of their business potential. The results will be communicated to all stakeholders including the system analyses, identified technology gaps and overall project conclusions.
Combined soil carbon sequestration and crop nutrient supply using thermal conversion technology residuals (INSURANCE)
The cycling of matter is fundamental in all ecosystems, but in the present urbanized society, such cycles are broken and carbon and valuable nutrients are often not brought back to the soil where the original biomass was exported from. Closing the cycles again is especially important since the society has to adapt to limitations in fossil oil supply and climate change and to shift towards an optimized use of biomass for food and energy purposes in the coming decades. The combination of flexibility and efficiency in biomass conversion has in recent years attracted increasing attention to the thermal gasification technology, but concepts to recycle the nutrient-rich ash material resulting from the process still have to be elaborated.
Mitigation of CO2 to reduce the impact of climate change requires immediate action and the involvement of several measures. However, technologies for combined energy production and residual recycling of crop nutrients and recalcitrant carbon to soils have only been developed to a limited degree. Likewise, business concepts including both energy and fertilizer production are still scarce even though countries, companies and consumers show increasing interest in intelligent whole system solutions for improved utilization of a range of biomass and waste streams. This applies also to Bregentved, one of Europe's largest agricultural companies with strategic interests in long term sustainable food and energy production. DTU and Dong Energy are at the forefront of the development of thermal conversion technologies adapted to a wide range of biomass feedstocks, which do not only provide energy with high efficiency but also a valuable ash residual. The focus on ash quality and applicability has, however, been limited so far.
The overall hypothesis of the proposed project is that the ash fraction resulting from thermal conversion can be developed into an attractive soil amendment for agricultural purposes. Blending ashes from different thermal conversion processes can furthermore be a tool to obtain a final product that provides the optimal amount of plant nutrients in an available form, with a simultaneously low content of heavy metals and other potentially toxic components (e.g. PAHs). Information about the fertilizer value acquired through the project will encourage the end-users (farmers) to take advantage of integrating such products into their fertilization strategies to maintain soil quality and reduce climate change impacts. In that way, the project will open a new venue for innovative energy and environmental technologies with promising new business opportunities.
To further test this hypothesis, the project will:
• Characterize ash materials after thermal conversion in terms of their content of PAHs, heavy metals, macro nutrients (phosphorous, potassium, calcium, magnesium, sulfur) and residual carbon
• Determine the short-term effects and mechanisms on soil fertility, nutrient dynamics and plant growth related to ash amendments
• Analyze effects of ash amendments on the potential soil carbon sequestration
• Develop suggestions for the use of ash as a fertilizer as well as soil improver for future agricultural systems, including economic feasibility and overall sustainability of the energy + fertilizer concept.
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