EXERGY AND EMERGY: COMPLEMENTARY TOOLS FOR ASSESSING THE ENVIRONMENTAL SUSTAINABILITY USE OF BIOSOLIDS GENERATED IN WASTEWATER-TREATMENT PLANT FOR ENERGYPRODUCTION

• Published in: Química nova 2022
• Main Authors: Cano, Natalia, Céspedes-Zuluaga, Santiago, Guerrero-Martin, Camilo, Gallego, Darío
• Format: Article
• Language: English
• ISSN: 0100-4042; 1678-7064
• DOI: 10.21577/0100-4042.20170806

Taking advantage of the energy contained in the biosolids generated in a wastewater treatment plant (WWTP) is one of the processes of greatest interest due to the opportunity to obtain an energy resources from a waste. The aim of this research was to analyze the environmental sustainability use of biosolids generated in a wastewater-treatment plant for energy-production by fluidized-bed gasification under exergy analysis. The energy-production system was based on previous studies of sustainable-emergy alternatives using biosolids. Sustainability of the process was evaluated by identifying stages in the energy-production system (from drying application to electricity generation) where it is possible to reduce useful energy losses as well as identifying the value of waste streams within the system through exergy analysis. It was illustrated the destroyed exergy and the efficiency by stage and by product in order to assess the effects of inefficiencies in the process sustainability. The mixture of biosolids with coal was identified as a highly sustainable stage of the process, as it presents the highest index of exergy sustainability (0.99), in contrast to the stages of energytransformation (turbine) and gas-cleaning, which efficiencies are 0.17 and 0.4, respectively. Energy-transformation and gas-cleaning stages are of interest in terms of an improved energy recovery process, making it more efficient by applying new technologies and/or using the waste streams that have high energy potentials.