Biomass gasification as a key technology to reduce the environmental impact of virgin olive oil production: a Life Cycle Assessment approach

Abstract

The olive oil value chain faces nowadays important challenges toward environmental sustainability, both in terms of waste management and energy efficiency improvement. This research work proposes an integrated gasification plant fueled with olive pomace for combined heat and power (CHP) generation and biochar production, which can be installed directly at oil mills. An alternative scenario for olive oil production incorporating the gasification technology was compared to a baseline scenario based on traditional olive oil production. The environmental impacts of producing 1 kg of unpacked virgin olive oil at the farming and industrial phases were estimated for both scenarios by following the Life Cycle Assessment (LCA) methodology under a “cradle-to-gate” approach. The gasification technology applied to the olive oil industry is able to manage all the pomace from the oil extraction process on site, avoiding transportation to pomace oil extraction plants. The proposed gasification plant generates 0.88 kWh of renewable electricity per kg of olive oil and enough heat to abandon the current practice of burning a significant part of the olive pit production. As a result, the alternative scenario contributes to a 8.25% reduction in the normalized environmental impact of olive oil production. In terms of climate change, the environmental impact of the functional unit is reduced from 2.21 to 1.74 kg CO2 eq. (−21%) and the industrial phase becomes a major carbon sink with −0.51 kg of CO2 eq. per kg of olive oil. In this regard, the integrated gasification plant is viewed as an attractive option for most olive oil mills to invest in sustainability through waste management and recovery.