[Paper Review] Can we improve the environmental benefits of biobased PET production through local 1 biomass value chains? A life cycle assessment perspective

Carlos García-Velásquez, Yvonne van der Meer|arXiv (Cornell University)|Jul 12, 2021

Bioeconomy and Sustainability Development23 references21 citations

TL;DR

This study evaluates the environmental performance of 30% and 100% biobased PET production using local European biomass feedstocks—sugar beet, wheat, and Miscanthus—via life cycle assessment (LCA) and global sensitivity analysis (GSA). It demonstrates that Miscanthus-based biobased PET offers the lowest greenhouse gas emissions and environmental impacts, outperforming imported feedstocks like Brazilian sugarcane and Indian molasses, and positions GSA-LCA integration as a key early-stage decision-support tool for optimizing sustainable bioplastics supply chains in Europe.

ABSTRACT

The transition to a low-carbon economy is one of the ambitions of the European Union for 2030. Biobased industries play an essential role in this transition. However, there has been an on-going discussion about the actual benefit of using biomass to produce biobased products, specifically the use of agricultural materials (e.g., corn and sugarcane). This paper presents the environmental impact assessment of 30% and 100% biobased PET (polyethylene terephthalate) production using EU biomass supply chains (e.g., sugar beet, wheat, and Miscanthus). An integral assessment between the life cycle assessment methodology and the global sensitivity assessment is presented as an early-stage support tool to propose and select supply chains that improve the environmental performance of biobased PET production. From the results, Miscanthus is the best option for the production of biobased PET: promoting EU local supply chains, reducing greenhouse gas (GHG) emissions (process and land-use change), and generating lower impacts in midpoint categories related to resource depletion, ecosystem quality, and human health. This tool can help improving the environmental performance of processes that could boost the shift to a low-carbon economy.

Motivation & Objective

• To assess the environmental impacts of 30% and 100% biobased PET production using local European biomass feedstocks (sugar beet, wheat, Miscanthus) versus imported alternatives.
• To evaluate whether local biomass value chains can enhance the environmental benefits of biobased PET production compared to current global supply chains.
• To integrate life cycle assessment (LCA) with global sensitivity analysis (GSA) as an early-stage decision-support tool for identifying optimal supply chain configurations.
• To identify key parameters influencing environmental performance, such as energy sources, agricultural practices, and allocation methods, to guide sustainable process design.

Proposed method

• Conducts a comparative life cycle assessment (LCA) of biobased PET production pathways using different feedstocks and supply chain configurations.
• Applies global sensitivity analysis (GSA) to quantify the influence of key parameters—such as energy matrix, fertilization practices, and allocation methods—on environmental impact results.
• Uses midpoint impact categories (e.g., climate change, resource depletion, ecosystem quality) to evaluate environmental performance across different scenarios.
• Incorporates biogenic carbon accounting within system boundaries to assess net greenhouse gas (GHG) emissions.
• Performs hotspot analysis to identify critical stages in the supply chain with the highest environmental impact.
• Integrates LCA and GSA as a decision-support framework to prioritize environmentally superior supply chain alternatives during early design phases.

Experimental results

Research questions

• RQ1 How do the environmental impacts of 30% and 100% biobased PET production compare when using local European biomass (sugar beet, wheat, Miscanthus) versus imported feedstocks (sugarcane from Brazil, molasses from India)?
• RQ2 Which biomass feedstock—first-generation (sugar beet, wheat) or second-generation (Miscanthus)—delivers the lowest environmental impact in biobased PET production?
• RQ3 How does the choice of energy source for biobased TPA production (e.g., coal vs. renewable electricity) affect the overall environmental performance?
• RQ4 What role do agricultural management practices (e.g., fertilization) and allocation methods play in determining the environmental impact of ethanol and MEG production?
• RQ5 Can the integration of LCA and global sensitivity analysis (GSA) serve as an effective early-stage tool for identifying and prioritizing environmental improvement strategies in biobased PET supply chains?

Key findings

• Miscanthus emerges as the optimal feedstock for biobased PET production, delivering the lowest greenhouse gas (GHG) emissions and environmental impacts across all midpoint impact categories.
• 100% biobased PET using Miscanthus reduces GHG emissions by up to 40% compared to fossil-based PET, primarily due to biogenic carbon sequestration and low land-use change emissions.
• Local European supply chains for biobased PET significantly outperform global supply chains relying on imported sugarcane or molasses in terms of environmental performance.
• The use of renewable energy sources (e.g., in Belgium, Germany, France) for biobased TPA production reduces GHG emissions more effectively than coal-based energy, highlighting the importance of clean energy integration.
• Global sensitivity analysis (GSA) identifies fertilization practices in sugar beet cultivation and the choice of allocation method in sugarcane molasses production as critical parameters influencing environmental impact uncertainty.
• The integrated LCA-GSA framework effectively identifies hotspots and key levers for improvement, enabling data-driven, early-stage decisions to enhance sustainability in biobased PET supply chains.