Abstract
Biodiesel is recognized as an important renewable energy source to fulfill global energy demand and resolve environmental issues. Despite its known advantages, it is still very critical to assess the sustainability of biodiesel production prior to the greater expansion for commercialization. The sustainability assessment can be conducted during process screening on the alternative biodiesel synthesis pathways. This is in line with Responsible Care, which commits chemical industries to consider safety, health and environmental (SHE) aspects when designing a new process. According to inherent safety principle, early hazard assessment offers greater benefits compared to the latter phases of lifecycle since the opportunity for making process modifications is higher yet requires lower cost. In this study, inherent SHE analysis is conducted for biodiesel production during the earliest design stage called process research and development (R&D) design. The inherent SHE assessment is done based on the fundamental information available, i.e. reaction chemistry and process condition. In this study, eight biodiesel production pathways via continuous transesterification process, such as catalyzed, supercritical and enzymatic transesterification, are identified and evaluated. Since multiple pathways need to be assessed based on multiple sustainability criteria, fuzzy optimization is used as the multi-criteria decision making tool in selecting the most optimum pathway. Based on the optimized result, pathway of enzymatic transesterification using fresh vegetable oil is identified as the optimum pathway which has least hazard in inherent SHE assessment.
