Turning Waste into Value: Technoeconomic Analysis and Life Cycle Assessment of Biodiesel-Derived Crude Glycerol Electrooxidation

The U.S. biodiesel industry faces significant economic challenges, exacerbated by declining glycerol coproduct values and rising feedstock costs and leading to numerous plant closures. In this study, we investigate the technoeconomic and environmental viability of electrochemically upcycling low-value industrial-grade crude glycerol (50 wt % glycerol) and methanol-depleted crude glycerol (80 wt % glycerol) into formic acid, a valuable chemical commodity. Through process modeling, we assess purification processes and electrochemical oxidation pathways for these waste glycerol streams. Our findings indicate that utilizing low-value crude glycerol can produce formic acid at competitive costs, contingent upon advancements in catalyst efficiency and reactor design. Life cycle assessments reveal that this approach could reduce environmental impacts compared to traditional formic acid production, especially as the U.S. electricity grid decarbonizes through additional renewable energy deployment. State-level analyses highlight the influence of regional electricity prices, water costs, policies, and incentives on economic feasibility. By enabling the circular use of biodiesel-derived waste, this work supports more resilient renewable fuel systems and advances sustainable chemical manufacturing.