Life cycle assessment of torrefied microalgae biomass using torrefaction severity index

• Main Author: Rivera, Diana Rose T.
• Format: text
• Language: English
• Published: Animo Repository 2019
• Subjects: Microalgae; Algal biofuels; Life cycle costing; Thermochemistry; Global warming; Energy Systems
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/7032
• Institution: De La Salle University

Torrefaction is a thermochemical process for upgrading raw biomass into a more energy dense fuel. In this study, a life cycle assessment was conducted to understand and assess the potential environmental impacts associated with the production of torrefied microalgal biomass, using a cradle-to-gate scope. Using different scenarios of torrefied microalgal biomass production, this study identifies the contribution of the torrefaction process to the overall environmental impacts. Using experimental data, the study was able to analyze the impact of the torrefaction severity index on the resulted environmental emissions. Result of the study shows that the torrefaction process had a minimal contribution of 1-20% to the resulted overall environmental impacts. The analysis revealed that the cultivation method had the highest contribution to the resulted environmental emissions when the cultivation is done using a photobioreactor while the drying process for the open pond method. For the upscaling production, regardless of the cultivation type, a decrease in the resulted environmental impacts was recorded. Moreover, the open pond has a lesser impact, 60% lower than the photobioreactor system. The inclusion of the torrefaction severity index (TSI) shows that there was a strong relationship between the TSI on the resulted GWP. It revealed that the influence of the torrefaction temperature was higher as compared to the torrefaction duration.