Application of life cycle assessment of integrated processes for organic waste valorization

Energy demand is one of the major significant contributors to environmental problems. This research aims to evaluate the environmental performance of a sustainable energy production pathway using the Life Cycle Assessment (LCA) methodology. The focus is on the integrated bio and electrochemical System (IBES), an innovative configuration of electrochemical cell combines with a dark fermentation process. The system was developed and experimentally tested in the environmental engineering laboratory at Sapienza University of Rome, Italy. IBES provided a self-sustained operational configuration produces enough electric current to derive a redox reaction for syngas (H2 +CO2) production. The research focuses mainly on addressing the complexity of IBES by evaluating the environmental impacts in relation to its key performance parameters such as hydrogen yield and maximum resource recovery benchmark with the conventional process, Anaerobic Digestion(AD). The LCA is conducted according to ISO14040:2006 and ISO14044:2006. The environment foot print 3.0(EF3.0) method is applied for impact calculations. The results showed that IBES outperformed in reduced impact of 2.94E+01kg CO2 eq/t.CW in climate change and 8.57E03kg. NMVOC eq/t.CW in photochemical ozone formation,as compared to baseline conventional AD process that is 2.02E+04kg CO2 eq/t.CW and 6.03E+00kg NMVOC eq/t.CW respectively. The IBES shows high freshwater ecotoxicity due to inorganic and metals pollutions, and resource demand in terms of energy use 7.00E+01MJ/t.CW and water use 3.51E+01 m3/t.CW. An insight into the handling of downstream degraded biomass feedstock and upgrading of produced syngas is applied while keepig the focus on Carbon Capture and Storage (CCS) to achieve potential benefits in terms of reduced impacts. The IBES is thus incorporated into an integrated biorefinery (IBR) approach converting biodegradable wastes into H2, carbonated residues, biochar, and many other by-products through an appropriate combination of bio, electrochemical and thermochemical processes. The environmental impact result showed reduced values over energy and water consumption, 2.80E+01MJ/t.CW and 3.28E+00 m3 depriv./t.CW, respectively. This concluded that the environmental implications do not reflect the operational and functional advantages that IBES offers over conventional AD such as improved waste treatment efficiency or increased energy recovery, unless IBES combined with downstream Integrated processes in an IBR and offers reduced impact effectively. This research identifies optimal solutions to reduced environmental impacts of various integrated process to provide a sustainable approach in IBR research practices.