An environmental and economic sustainability assessment of novel rhamnogalacturonan-I pectin production from agricultural residues

This study presents for the first time an environmental and economic assessment of large-scale process configurations employing novel technologies for rhamnogalacturonan-I pectin production from sugar beet pulp (SBP) and discarded red beetroot (DRB). Three alternatives to conventional acidic extraction (CE) were compared. Alternatives 1 and 2 focused on pectin derived from SBP, combining acid-free microwave assisted extraction (MAE) or hydrothermal extraction (HE), respectively, whilst Alternative 3 considered pectin extraction from DRB using MAE. All alternatives shared a membrane filtration and freeze drying downstream processing. Prospective life cycle assessment (LCA) and techno-economic analysis (TEA) were performed using scaled-up data from own experimental extraction and purification results using process simulation. The assessment was from cradle-to-gate for the “production of 1 kg of pectin”, considering eight environmental impacts and six economic indicators including climate change (CC) and minimum selling price (MSP). The CC impacts were reduced by 89.3 – 94.4% in the alternatives compared to the Reference case because of introducing solvent-free downstream processing. The MSP ranged from 16.2 to 56.0 €/kg, with the alternative processes showing better economic feasibility, which can be further increased through the co-production of DRB juice based on the findings from a sensitivity analysis. The processes were ranked based on overall eco-efficiency scores as follows: A3 (0.91) > A1 (0.73) > A2 (0.62) >> Reference case (0.05), highlighting the environmental and economic advantage of MAE and valorization of DRB, emphasizing the promise of emerging technologies and alternative feedstocks for developing more sustainable and competitive pectin production processes. • Optimal conditions for POS recovery from SBP by HE found at 153 ºC and 59 minutes • Process configuration based on emerging technologies offer climate change reductions of up to 94% • Process configuration based on emerging technologies showed lowest production costs • DRB is the most economically viable feedstock for pectin production • The use of MAE and DRB feedstock scored highest overall eco-efficiency