(471g) Optimal Selection and Location of Nutrient Recovery Systems Considering Standalone and Coordinated Strategies

Human farming and agricultural activities have altered nutrient cycles; this has been the result of the technification and intensification of production processes, which decreases the mobility and availability of nitrogen and phosphorus. Among the anthropogenic activities, the agricultural sector is the main source of phosphorus emissions [1]. Livestock farming generates substantial amounts of organic waste, being linked with an in-excess nutrient concentration in soils and water [2]. The implementation of sustainable nutrient management processes aids the recycling of non-renewable resources essential to supporting life and mitigating nutrient pollution of waterbodies and soil degradation [3].

In this work, the selection, implementation, and performance evaluation of different state-of-the-art nutrient recovery technologies at livestock facilities are assessed from both standalone and logistics network perspectives and are coupled with electricity production through anaerobic digestion of manure [4]. On the one hand, following a standalone approach, the individual facilities are evaluated considering their characteristics regarding size, type, as well as its location to reflect local environmental and nutrient pollution conditions due to legacy and new inputs of nutrients. In addition, the location and choice of nutrient recovery systems are evaluated using a logistics network framework where the potential coordination between facilities for nutrient recovery is included in the analysis. Allowing scenarios in which there is coordination is beneficial due to the economies of scale by transporting organic waste to centralized facilities for energy and nutrient recovery. The evaluation of both approaches allows studying the economic feasibility of operating nutrient recovery facilities, determining if the concentrated animal feeding operations can operate nutrient recovery processes in a standalone mode or, conversely, they should be centralized in large management facilities, even if this accounts for transportation costs of high-water content livestock waste. Besides, the effect of different policy incentives for installing nutrient and energy recovery technologies, including RECs (Renewable Energy Credits) and hypothetical nutrient credits, are evaluated.

The developed framework is applied to a series of real case studies of cattle facilities in the U.S. by considering the location and size of livestock farms. Therefore, this determines the optimal distribution of nutrient and energy recovery processes. Finally, this framework develops heuristic rules that can be used as guidelines by the stakeholders involved in the decision-making process for designing and implementing coordinated nutrient management systems.

References

[1] Dzombak, D. A. (2011). Nutrient Control in Large-Scale U.S. Watersheds. The Bridge, 41 (4), 13–22.

[2] Sampat, A., Martı́n, E., Martı́n, M., & Zavala, V. (2017). Optimization formulations for multi-product supply chain networks. Comput. Chem. Eng., 104 , 296-310.

[3] Cervantes, Francisco J. Environmental Technologies to Treat Nitrogen Pollution. IWA Publishing, 2009.

[4] Martín-Hernández, E., Sampat, A., Zavala, V., & Martı́n, M. (2018). Optimal integrated facility for waste processing. Chem. Eng. Res. Des., 131 , 160-182.