Life Cycle Energy of Renewably Produced Nitrogen Fertilizers
The Minnesota landscape supports over 14 million acres of grain production, which requires almost 600,000 tons of nitrogen fertilizers and costs over $400 million annually. Producing this fertilizer consumes the equivalent of 3,000,000 barrels of oil, which is a significant use of fossil fuels resulting in a considerable amount of greenhouse gas emissions. Minnesota has renewable technologies that are capable of the constant energy generation needed to produce ammonia, which would promote economic development, spur job creation in rural areas and improve the overall sustainability of agriculture. This project examined the viability of developing these baseload renewable energy sources for ammonia production.
Using life-cycle assessment and techno-economic modeling, the research examined ammonia production with three renewable energy options; gasification, anaerobic digestion and hydroelectric systems. The findings indicate that from both a technical and environmental standpoint, these renewable production systems can produce renewable ammonia fertilizer. However, the present economics make investing in renewable ammonia production unfeasible at this time. The current and continued low price of natural gas prices suggests that low cost fossil-based ammonia is a more economical option at this point. Past shortages and price spikes in ammonia fertilizers indicate that the economics and need for the systems might re-appear under different conditions. Yet, it is unlikely that these renewable ammonia systems would be viable in the short term without a significant consumer or other regulatory demand. Ammonia fertilizer is critical to Minnesota’s agriculture and the information from this study is available should alternative ammonia production need to be implemented on short notice.
Funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund* as recommended by the Legislative ‐ Citizen Commission on Minnesota Resources (LCCMR). Project Manager: Dr. Joel Tallaksen, Renewable Energy Scientist, University of Minnesota West Central Research and Outreach Center, Morris, Minnesota.
* The Trust Fund is a permanent fund constitutionally established by the citizens of Minnesota to assist in the protection, conservation, preservation, and enhancement of the state’s air, water, land, fish, wildlife, and other natural resources. Currently 40% of net Minnesota State Lottery proceeds are dedicated to growing the Trust Fund and ensuring future benefits for Minnesota’s environment and natural resources.
Dr. Christian Hulteberg, Department of Chemical Engineering, Lund University, Lund, Sweden
Dr. Serina Ahlgren, Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Modeling Anaerobic Digestion Based Ammonia Production (PDF)
- Gasification-Based Ammonia Ethanol Production Model (PDF)