Avaliação da produção de biodiesel de algas- análise exergética, exergoeconômica e exergoambiental

Abstract

Due to the environmental impacts caused by fossil fuels, such as air pollution, contributing to climate changes, among others, alternatives to these fuels are needed. Algae biodiesel is a renewable alternative to diesel. Algae promote carbon dioxide capture during production, reproduce quickly and do not compete for land use, indicating that the fuel produced by raw material is environmentally advantageous. In the present work, an algal biodiesel production plant was analyzed from an exergetic, exergoeconomic and exergoenvironmental point of view. The Specific Exergy Costing (SPECO) methodology was utilized to define fuel and products. The cost of biodiesel and glicerin produced was 459.42 $/ton and 331.84 $/ton, respectively. A life cycle analysis (LCA) was developed by applying the eco-indicator 99 method, it was calculated that the environmental impact of biodiesel produced was 182.55 mPt/kg, and the glycerin was 133.84 mPt/kg. The PBR showed the worst exergetic of exergetic efficiency (11.46%) and the highest exergy destruction (2,123.66 GJ). In addition to it, the PBR presented the greatest relative difference in cost (6,706.06%) and environmental impacts (859.62%). The lowest exergoeconomic factor was obtained in mixer #1 (0.18%). The exergoenvironmental factors of the equipment in general were low, indicating that exergy destruction is the dominant factor in the environmental impacts of the plant. The exergetic, exergoeconomic and exergoenvironmental analyses show that there is scope for optimizing the plant in order to minimize its costs and environmental impacts. Thus, the biodiesel produced would have lower cost and environmental impacts. It could turn more viable the production of a fuel, which is accessible, renewable, cleaner than diesel and it could help in climate changing fight.