Is anaerobic digestion a feasible alternative to the combustion of olive mill solid waste in terms of energy production? A critical review

The use of olive mill solid waste (OMSW) for energy production has mainly been promoted through combustion processes. However, the EU is promoting the substitution of combustion in favor of greener alternatives. Several publications have stated that the energy obtained from anaerobic digestion (AD) is a feasible waste-to-energy technology for OMSW. However, these studies lack reliable energy balances that can assess this statement. The present research work aims to address this issue by evaluating the energy potential of the biomethanization of OMSW in comparison with the current combustion technology, based on a review of the available scientific literature. The present analysis demonstrates that the AD of OMSW can generate a net energy production in the same range as that obtained from the OMSW combustion, qualifying AD as an alternative to combustion but not clearly offering a surplus of energy production. (c) 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd