Net Energy Analysis of Pyrolyzed Olive Pomace Using Life Cycle Assessment

This paper uses a life cycle assessment approach to conduct a net energy analysis of pyrolyzed olive pomace. The study establishes a system boundary called “cradle-to-bioenergy products” and utilizes a functional unit of 100 kilograms of olive pomace. The analysis uses the Cumulative Energy Demand method within SimaPro V9.5. The results indicate that the total energy consumption amounts to a total energy output of 638.33 MJ. Comparing the energy consumption during the whole life cycle, which is 3670.27 MJ, yields an energy ratio of 0.17. Although the use of pyrolyzed olive pomace shows a positive environmental impact, energy ratio revealed that it is an energy intensive process. The result shows the energy consumption's order from lowest to highest to lowest as cultivation and harvesting (28.3%), pyrolysis stage (34.4%), and oil extraction phase (37.3%). The percentage allocation of the impact category from highest to lowest are fossil (non-renewable) at 53.48%, nuclear (non-renewable) at 27.29%, biomass (renewable) at 6.74%, wind, solar, geothermal (renewable) at 6.68%, water (renewable) at 5.4%, and biomass (non-renewable) at 0.4%. To address environmental concerns and reduce energy consumption, shifting towards renewable energy sources can help lower electricity usage. Recommendation on technology innovation and process optimization are also recommended.

I. Introduction

Pyrolysis is a thermochemical process that convert biomass to produce biofuel. This process involves heating the feedstock at a temperature for 5 to 60 minutes, all in an oxygen-free environment. Pyrolysis also has the added benefit of increasing the heating value of biomass, making it a viable alternative to coal. It also offers advantages over green biomass, such as improved uniformity, higher energy density, and enhanced grindability. Studies show that it also reduces moisture levels and alters hygroscopic properties, which in turn helps extend the shelf life of biomass and mitigate storage issues [1], [2].