Water Availability for Biorefineries in the Contiguous United States and the Implications for Bioenergy Production Distribution

Abstract

Renewable biofuel production depends on many factors, including feedstock availability, refinery and shipment infrastructure, and in particular, water availability. This study assesses water requirement and availability for mainstream biorefinery technologies in the contiguous United States (CONUS). The assessment is conducted in newly defined spatial units, namely, biorefinery planning boundaries, considering feedstock availability, transportation cost, and refinery capacity requirement for cost-effectiveness. The results suggest that the total biorefinery water use in the CONUS by 2030 will be low compared to the total water availability. However, biorefinery water requirements can aggravate the water stress situation in many regions, including the Great Plains, California Central Valley, and the upper Columbia-Snake River basin in Washington. Bioenergy productions in these regions can be largely constrained by water. It is projected that biofuel production will concentrate in Northern Plains, Lake States, and Corn Belt regions, which contribute 94.4% of the conventional, 86.1% of biodiesel, and 54.8% of cellulosic biofuel production mandated by the renewable fuel standard. If biorefineries are constrained to use less than 10% of the locally available water, up to 7% of planned cellulosic biofuel production will be affected. Findings from this study can aid the sustainable planning of national bioenergy production.

Design of a High-Rate Wastewater Treatment Process for Energy and Water Recovery at Biorefineries

“…Further, without on-site treatment, the biorefineries would not be able to reuse the process water, which would lead to higher water usage that could limit the available deployment sites for biorefineries. 63 However, as off-site wastewater treatment would reduce the physical footprint, capital cost, and operation and maintenance needs of the biorefinery, it could be a suitable option for some biorefineries (e.g., small biorefineries that are close to a wastewater treatment plant with available capacity). Although locality specific contextual parameters are outside the scope of this work, future studies may evaluate the implications of local context on the deployment of energy and water recovery at biorefineries.…”

“…This would substantially increase the life cycle GHG emissions of the 1G biorefineries because the conventional activated sludge would incur high aeration electricity usage with no energy recovery at the biorefinery. Further, without on-site treatment, the biorefineries would not be able to reuse the process water, which would lead to higher water usage that could limit the available deployment sites for biorefineries . However, as off-site wastewater treatment would reduce the physical footprint, capital cost, and operation and maintenance needs of the biorefinery, it could be a suitable option for some biorefineries (e.g., small biorefineries that are close to a wastewater treatment plant with available capacity).…”

“…Biorefineriesespecially 2G biorefineries leveraging cellulosic feedstockshave the potential to play a critical role in alleviating climate change and supporting the society’s transition toward a more sustainable future . However, their development has been impeded by uncertainty in their financial viability, and recent studies have also raised concerns regarding their requirements for resources, including water . Considering the large demand of freshwater and the high strength of generated wastewater, proper management of the water streams is crucial to the sustainability of biorefineries.…”

“…67 However, their development has been impeded by uncertainty in their financial viability, and recent studies have also raised concerns regarding their requirements for resources, including water. 63 Considering the large demand of freshwater and the high strength of generated wastewater, proper management of the water streams is crucial to the sustainability of biorefineries. In this study, we designed a high-rate WWT process using emerging high-rate anaerobic technologies tailored for the context of biorefinery, and we evaluated the economic and environmental implications of implementing this WWT process in seven biorefineries covering a range of feedstocks and products.…”