Environmental life cycle assessment of olive pomace utilization in Turkey

Abstract

Turkey is one of the top five producers of olive oil in the globe. Olive pomace, a by-product of olive oil production, has several environmental impacts on the ecosystem when untreated. In this study we compared five different scenarios for the treatment and utilization olive pomace in terms of their life cycle environmental impacts. These scenarios include i) traditional, ii) two-phase, and iii) three-phase production of olive oil followed by producing biofuel pellets from the olive pomace, iv) producing fodder additives from olive pomace, and v) composting the olive pomace. The functional unit was chosen as olive pomace produced as a result of the production of 1 kg of olive oil. The following impacts were calculated by using CCaLC software and CML2001 method, with a gate-to-grave approach: global warming potential, acidification potential, eutrophication potential, ozone layer depletion, photochemical smog formation potential, and human toxicity potential. An overall impact calculation was also performed by normalizing the individual impacts and assigning equal weights to them. The first three scenarios were observed to have significantly lower impacts, and in many cases even impact credits for the system, mainly due to the fact that utilizing the biofuel pellet eliminates the consumption, thus the production of natural gas, which has especially high environmental impacts in case of Turkey. Traditional olive oil production was found to have a lower overall impact compared to two-phase and three-phase production. For most of the impacts, operational processes and utilization emerged as the hotspots. This study is considered to be a valuable guide for the olive oil sector in Turkey in terms of reducing its environmental footprint while getting economic gain. This particular study is novel in the sense that to the best of our knowledge, it is the first study conducted in Turkey in which a comprehensive life cycle assessment of utilizing olive pomace has been conducted. Future studies on this topic should focus on the consequential life cycle assessment of the nation-wide implementation of the scenarios analyzed in this work.