Life-Cycle Sustainability Analysis of Renewable Drop-In Diesel Fuels Produced from Waste Feedstocks for Co-Optima Heavy-Duty Vehicles
Dr. Hao Cai, Principal Environmental Analyst, Argonne National Laboratory
Recent research and development effort of the U.S. Department of Energy Co-Optimization of Fuels & Engines (Co-Optima) initiative explores diesel-like drop-in renewable fuels designed to enable low-emission heavy-duty engines. Wet waste feedstocks, such as animal manure, fats, oils, and greases (FOG), among others, are being considered as alternative, lower-cost, and lower-environmental impact feedstock options to improve value proposition of Co-Optima diesel vehicles and to promote large-scale production of diesel-like renewable fuels with emission-reduction fuel properties for heavy-duty vehicle application. We present our life-cycle analysis work that evaluates sustainability performance of utilizing animal manure and FOG as two promising wet waste feedstocks for conversion via hydrothermal liquefaction (HTL) and hydrogenation/hydrocracking, respectively, for production of renewable diesel-like fuels with favorable fuel properties for heavy-duty vehicle application. We focus on these waste feedstocks based on our review and evaluation of resource availability, geographical distribution and logistics, quality characteristics, and current utilization status and potential for fuel production. Meanwhile, several feasible locations that offer production of renewable diesel fuels at scale with such waste feedstocks are identified, and a scenario to co-feed up to 50% soybean oil with FOG to expand the biorefinery capacity for economic viability is also being considered. We present and discuss results and key drivers of life-cycle greenhouse gas (GHG) emissions and fossil energy consumption of such waste-to-energy pathways. We also discuss sustainability implications of key issues such as common waste management practices in reference scenarios for these waste-to-energy pathways.
Dr. Hao Cai, is a Principal Environmental Analyst in the Systems Assessment Center at Argonne National Laboratory. He is a PI of multiple DOE-funded research projects addressing sustainability of technologies research and development for production of alternative fuels and products. He is part of the GREET development team and has been contributing to expansion and updates of the widely used LCA model with his research on the supply chain of transportation fuels including biofuels produced from waste resources. He has authored more than 40 journal articles and numerous peer-reviewed technical reports in the area of transportation fuels and products LCA.