Uncovering the environmental and economic feasibility of an integral tomato-based biorefinery for obtaining pectin and seed oil

Abstract

The combination of life cycle assessment and techno-economic analysis enables the evaluation of a biorefinery’s viability from both environmental and economic perspectives. This is particularly relevant for valorising food industry by-products within the framework of a circular economy. This study focuses on the integral valorisation of tomato pomace by separating seeds and skins to obtain oil and pectin, respectively. For each valorisation route, two technologies were assessed: cold pressing and supercritical CO₂ extraction for seeds, and acid extraction and ultrasound-assisted extraction for peels. Of these, cold pressing and acid extraction were identified as the best options in terms of environmental performance and yield for seeds and for peels, respectively. The corresponding emissions were 33.6 kg CO₂ eq and 0.08 kg SO₂ eq per kg of oil, and 44.8 kg CO₂ eq and 0.12 kg SO₂ eq per kg of pectin, for global warming and terrestrial acidification respectively. These impacts could be significantly reduced by modifying the heat source, identified as the system’s main hotspot. Economically, the biorefinery with the best environmental performance was not profitable under current conditions. However, sensitivity analysis showed that improving oil yield by a factor of 2.6 through technological adjustments could lead to economic viability. These findings provide valuable insights for stakeholders and policymakers seeking sustainable solutions for food waste management, supporting both environmental responsibility and techno-economic feasibility.