The eucalyptus tree has excellent potential for wood production. The rate of eucalyptus forest plantation has sharply improved in the last decade, as it is a productive resource for bio-energy and activated carbon (AC) production. Some works have reported on the environmental impacts of eucalyptus wood valorization via slow or fast pyrolysis to produce bio-oil/AC, but the comparison between their environmental burdens using Life Cycle Assessment (LCA) is yet to be made and examined. Hence, the purpose of this study was to identify the most eco-friendly product from eucalyptus wood through LCA methodology. Three scenarios were evaluated: bio-oil production via fast pyrolysis (denoted by bio-oil), AC production via slow pyrolysis (denoted by AC), and AC production using two activating agents: ZnCl2 and H3PO4 (defined by activating agent). The functional unit was 1 kg of pyrolysis product of eucalyptus wood. Three LCA methods were applied: CML 2 baseline 2000, Cumulative Energy Demand (CED) and Product Environmental Footprint (PEF) to quantify, assess, and compare the potential environmental impacts of bio-oil and AC. The findings indicated that the bio-oil scenario had lower indicator values across all impact categories than the AC scenario. AC production using zinc chloride as the activating agent had higher environmental burdens for most of the impact categories compared to that with H3PO4. Meanwhile, the total energy demand for the production of 1 kg of AC using ZnCl2 (AC-ZnCl2), AC using H3PO4 (AC-H3PO4), and bio-oil was 118.6, 153.8, and 16 MJ, respectively. Nevertheless, renewable energy represents 11.8%, 16.2%, and 84.1% of the total energy consumption during the AC-ZnCl2, AC-H3PO4, and bio-oil production, respectively. This study demonstrated that the eco-friendly option for eucalyptus wood waste management is bio-oil, as well as biochar production using a fast pyrolysis process, is. In addition, the chemicals activating agent played a crucial role in creating the environmental impacts of AC production in slow pyrolysis.

Keywords