Life Cycle Assessment of Raw and Fe-Modified Biochars: Contributing to Circular Economy

Abstract

Biochar is a carbonaceous material, which can be decorated with metals, that has been garnering attention to be used in the treatment of water due to its contribution to waste management and circular economy. This study presents the life cycle assessment (LCA) regarding the generation of Pinus patula raw biochar and its modification with iron (Fe-modified biochar). SimaPro 9.3.0.3 software was used to simulate the environmental impacts of both carbonaceous materials. The potential environmental effects obtained from the production of Pinus patula raw biochar were mainly ascribed to the source of energy utilized during this process. The potential impacts demonstrated that the generation of gases and polycyclic aromatic hydrocarbons are the main concern. In the case of Fe-modified biochar, the potential environmental effects differed only in the stage of the biomass modification with the metal. These effects are associated with the extraction of Fe and the generation of wastewater. These findings provide an insight into the environmental effects linked to the production of raw and Fe-modified biochar. However, further LCA research should be performed concerning other materials and compounds than can be generated during the biomass thermochemical conversion.

Life Cycle Assessment of Production of Hydrochar via Hydrothermal Carbonization of Date Palm Fronds Biomass

“…Removing carboxyl and -OH groups substantially reduces the O/C and the H/C atomic ratios to render the final product HTC "denser" [16] (Romano et al, 2023). In our HTC process [10], we observed that it followed a trend corresponding to a dehydration process with a minor occurrence of the decarboxylation process.…”

“…Similarly, Thornley and co-researchers [9] utilized LCA and indicated that biochar production systems can potentially deliver the highest greenhouse gas reductions per unit area of land in comparison with other bioenergy systems (electricity, heat and chemical). Recently, Gallego-Ramírez and co-researchers [10] conducted a life cycle assessment (LCA) on the generation of Pinus patula raw biochar and discovered that the predominant impacts were attributed to the generation of gases and polycyclic aromatic hydrocarbons.…”

“…It should be noted that hydrochar is synthesized from a slurry (i.e., a two-phase mixture of solid and liquid) using HTC while biochar can be synthesized as a solid by-product material in a dry carbonization process such as pyrolysis [13]. One of our previous studies [10] focused on utilizing the carbon microspheres for the adsorption of methylene blue, a common dye pollutant found in wastewater. The results highlighted the effectiveness of the carbon microspheres derived from palm biomass in removing methylene blue from aqueous solutions.…”