New Life-Cycle Assessment research evaluates greenhouse gas emission and environmental impact of 15 promising biochemicals
Combatting climate change means finding fossil fuel alternatives wherever possible. Biochemicals are a promising alternative, but chemicals today are still mainly produced from fossil fuels such as crude oil and natural gas.
Researchers from Northwestern University and Argonne National Laboratory recently set out to evaluate the sustainability benefits of biochemicals that can aid in their prioritization and expedited use based on their greenhouse gas or energy savings compared to conventional fossil-fuel derived chemicals.
The team profiled 15 biochemicals that may be able to reduce the carbon footprint of everyday products from fuels to food stabilizers to cosmetics and medicines. The study builds on growing consumer demand for more sustainable materials and products and new government incentives for renewable fuels research and development.
The research is a part of a collaborative initiative, known as Responsible Innovation for Highly Recyclable Plastics, or ‘ResIn’, which is funded by the U.S. Department of Energy (DOE).
Biochemicals can be made using different types of biomass, such as agricultural residue from corn fields or algae. They can be produced in integrated biorefineries that also produce fuels from biomass. Shifting the composition of fuels and chemical products towards biobased options means reducing reliance on fossil fuels. Because there are many up-and-coming biochemicals, the research team took a closer look at 15 options that have the greatest market potential.
“Our analysis of these chemicals covers their full supply chain from raw materials through manufacturing and considers energy and water consumption alongside greenhouse gas emissions,” remarked Jennifer B. Dunn. The team’s analysis is grounded in life-cycle assessment, a robust and structured method to account for all inputs and emissions involved in making a given product.
One of the four researchers on the team, Dunn is an associate professor of chemical and biological engineering at Northwestern’s Robert R. McCormick School of Engineering and Applied Science and Associate Director of Northwestern’s Center for Engineering Sustainability and Resilience (CESR). She also is a member of the Program on Plastics, Ecosystems and Public Health (PEPH) at the Institute for Sustainability and Energy at Northwestern (ISEN). Chao Liang, postdoctoral scholar at ISEN, is the study’s lead author. Co-authors hailing from Argonne National Laboratory are Troy R. Hawkins, group manager of fuels and products, and Ulises R. Gracida-Alvarez, energy systems analyst.
Our analysis of these chemicals covers their full supply chain from raw materials through manufacturing and considers energy and water consumption alongside greenhouse gas emissions.”
Switching from fossil-fuel-based chemicals to biobased alternatives could prevent 120 million metric tons of CO2 emissions every year. This change is, “a reduction of greenhouse gas emissions equivalent to removing 26 million cars from the road annually. [That’s] approximately 10% of the cars currently on the road in the U.S.,” shared lead author Chao Liang. While promising, the full transition to bio-based alternatives is up against a well-oiled machine: the fossil fuel industry. “The fossil fuel supply chain is so efficient after decades of being used and developed,” explained Dunn.
This fall, the analysis of the 15 biochemicals included in the study will be made publicly available in Argonne National Laboratory’s Greenhouse Gases Regulated Emissions and Energy Technologies (GREET) model, which houses data about the energy and environmental impacts of fossil and biobased products. “We hope it will be helpful for the life-cycle assessment community, companies that make products from these biomaterials, and researchers thinking about where to start,” said Dunn.
The GREET model is widely used by over 40,000 people worldwide. It has informed policy development around renewable fuels and was mentioned several times in the 2022 Inflation Reduction Act, which set targets for environmental performance and life-cycle thinking. “Having work included in GREET is a great way to enhance our broader impacts,” Dunn reflected.
One important element of the study was an assessment of which biochemicals make the most strategic co-products for biofuels in integrated biorefineries that produce both fuels and chemicals, much like today’s petrochemical refineries. Co-producing biofuels and bioproducts may enhance biorefinery economics and can overall boost society’s shift to a more bio-based economy. Bioproducts that have large market potential, a high selling price, and large greenhouse gas reductions are particularly promising as co-products.
Dunn and Liang imagine a future where the cost of greenhouse gas emissions as well as fossil fuel and water consumption are part of chemical product evaluation. “If there were carbon credits available for reducing greenhouse gas emissions by producing a chemical from biomass versus fossil fuels, the cost of [biochemicals] could go down,” Dunn shared. Even more, Liang sees carbon credits as a “powerful incentive that could generate revenue, offset costs, and increase the marketability of biochemicals.”
Better understanding the true economic cost of bioproducts may help bring them to market more quickly in hopes of speeding up the transition to fuels and chemicals with a minimal environmental footprint.
Within ResIn, life-cycle assessment will continue to be used as a tool to evaluate different technologies and materials. “Sometimes life-cycle assessment results vary depending on the methodology used which can cause confusion among stakeholders of the bioeconomy,” said Dunn. The hope is that research will provide a consistent LCA method for biochemicals that can be used by the broader scientific community.
Published on February 6, 2023, the study “Life-Cycle Assessment of Biochemicals with Clear Near-Term Market Potential,” was supported by the Office of Energy Efficiency and Renewable Energy of the U.S. Department of Energy (DOE) under contracts DE-EE0008928 and DE-AC02-06CH11357.