Environmental impact assessment of different pretreatment processes for high phenolic bio-oil production through fast-pyrolysis of olive pomace

Abstract

Sustainable phenol production from agricultural waste as a valorization process was conducted in this study. The study assesses the environmental performance of multiple production scenarios of high phenolic bio-oil from olive pomace. Multiple pretreatment combined with fast pyrolysis is chosen as a transformational process from olive pomace into high phenolic bio-oil. A life cycle assessment (LCA) was conducted using a functional unit of 100 kg/h of phenol and a gate-to-gate approach to compare each scenario's environmental impacts, aiming to mitigate ecological damage and identify the eco-friendly production route for phenolic bio-oil. Experimental data from previous studies were used to perform simulations using Aspen Plus® for material and energy balance calculations and SimaPro software to evaluate the environmental performance of all processes. This study highlights three major environmental impact categories related to human health, resource depletion, and ecosystem damage were identified as well as human health as the main impact. Acid and hydrothermal carbonization pretreatment routes massively consume resources and energy, producing significant emissions that adversely affect human health. On the other hand, torrefaction shows remarkable environmental performance indicated by lower emissions, high bio-oil yield, and lower resource consumption compared to other processes. The result premises the potential of torrefaction pretreatment scenarios as an environmentally friendly process for producing high phenolic bio-oil from olive pomaces.