In Europe, the thermal treatment in dedicated waste-to-energy facilities is a widespread method to avoid landfilling and achieve energy recovery from unrecyclable waste fractions. The flip side of the process is the emission of waste-related airborne contaminants, like acid gases (mainly, HCl and SO2). Currently, control of acid gas emissions is regulated by the Industrial Emissions Directive (Directive 2010/75/EU) and dry acid gas removal systems, based on the injection of solid sorbents like calcium hydroxide or sodium bicarbonate, are particularly valued for coupling compliance to emission limit values with cost-effectiveness and ease of operation. However, the modern holistic approach to environmental protection goes beyond regulatory compliance and calls for due consideration of indirect environmental burdens other than the bare stack emissions at plant. Despite boasting the same acid gas removal efficiency, two flue gas cleaning technologies might give rise to different environmental impacts related to the supply of reactants and the management of process residues. The evaluation of life cycle impacts has to support traditional economic decision-making in order to define the soundness of a flue gas cleaning technology in terms of overall sustainability. In the present study, single-stage and multi-stage process alternatives for dry acid gas removal were put in comparison, following a methodology which included the quantification of the indirect environmental burdens, arisen along the supply and disposal chain of reactants and residues, and the evaluation of the economic performance in terms of operating and capital costs. The analysis allowed to identify the sustainability profile of alternatives for different operating conditions (waste composition, required acid gas removal efficiency). A properly operated multi-stage treatment system resulted more cost-effective without introducing indirect environmental impacts. A sensitivity analysis confirmed the robustness of the results even in presence of broad uncertainties in the input data.
Alessandro Dal Pozzo, D.G. (2017). ACCOUNTING FOR THE INDIRECT ENVIRONMENTAL BURDENS IN WASTE-TO-ENERGY FLUE GAS CLEANING: A SUSTAINABILITY ASSESSMENT OF DRY ACID GAS REMOVAL SYSTEMS.
ACCOUNTING FOR THE INDIRECT ENVIRONMENTAL BURDENS IN WASTE-TO-ENERGY FLUE GAS CLEANING: A SUSTAINABILITY ASSESSMENT OF DRY ACID GAS REMOVAL SYSTEMS
Alessandro Dal Pozzo;Daniele Guglielmi;Giacomo Antonioni;Alessandro Tugnoli
2017
Abstract
In Europe, the thermal treatment in dedicated waste-to-energy facilities is a widespread method to avoid landfilling and achieve energy recovery from unrecyclable waste fractions. The flip side of the process is the emission of waste-related airborne contaminants, like acid gases (mainly, HCl and SO2). Currently, control of acid gas emissions is regulated by the Industrial Emissions Directive (Directive 2010/75/EU) and dry acid gas removal systems, based on the injection of solid sorbents like calcium hydroxide or sodium bicarbonate, are particularly valued for coupling compliance to emission limit values with cost-effectiveness and ease of operation. However, the modern holistic approach to environmental protection goes beyond regulatory compliance and calls for due consideration of indirect environmental burdens other than the bare stack emissions at plant. Despite boasting the same acid gas removal efficiency, two flue gas cleaning technologies might give rise to different environmental impacts related to the supply of reactants and the management of process residues. The evaluation of life cycle impacts has to support traditional economic decision-making in order to define the soundness of a flue gas cleaning technology in terms of overall sustainability. In the present study, single-stage and multi-stage process alternatives for dry acid gas removal were put in comparison, following a methodology which included the quantification of the indirect environmental burdens, arisen along the supply and disposal chain of reactants and residues, and the evaluation of the economic performance in terms of operating and capital costs. The analysis allowed to identify the sustainability profile of alternatives for different operating conditions (waste composition, required acid gas removal efficiency). A properly operated multi-stage treatment system resulted more cost-effective without introducing indirect environmental impacts. A sensitivity analysis confirmed the robustness of the results even in presence of broad uncertainties in the input data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
