Exergo-environmental life cycle assessment of biodiesel production from mutton tallow transesterification

The results obtained show that approximately 83.3% of the exergy fed to the process is recovered in the useful product (biodiesel). The transesterification reactor should have the highest priority for process improvement from the thermodynamic point of view. However, the environmental improvements of the entire biodiesel production system should be focused on minimizing methanol consumption. The net energy ratio of the system is approximately 2.3. Therefore, the biodiesel system presents a net energy gain. Using economic allocation instead of the mass-based approach leads to an increase in the life cycle indicators by approximately 11%. However, this difference is only 6.7% when considering energy allocation.