From Fossil to Bio-Based Acrylic Acid: A Techno-Environmental Comparison of Propylene and Glycerol Pathways

The growing demand for acrylic acid, driven by its widespread use in polymers and specialty chemicals, raises concerns regarding the environmental impact of its conventional fossil-based production. In this context, the present study evaluates the techno-environmental performance of a glycerol-based acrylic acid route compared to the conventional propylene pathway. Process simulations were carried out using CHEMCAD for an annual capacity of 50,000 tons. The environmental impact is assessed through Life Cycle Assessment (LCA) methodology and LCA for Experts software, following the ReCiPe 2016 (H) impact method. The results show that the glycerol-based route requires higher raw material input (1.90 kg/kg acrylic acid) than the propylene pathway (0.84 kg/kg acrylic acid), yet generates slightly lower liquid wastes (3.25 kg/kg acrylic acid vs. 3.60 kg/kg acrylic acid). From an environmental standpoint, the glycerol route performs better in 12 of 16 impact categories. The conventional process is dominated by the propylene supply chain, contributing up to 62% of the global warming impact, while electricity demand ranks second in the glycerol-based route. Scenario analysis based on future European electricity mixes (EU-2030 and EU-2050) further reduces climate and fossil depletion impacts, although with increased mineral resource use. Overall, the results highlight the potential of glycerol as an alternative feedstock and the key role of electricity sourcing.