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Title: High temperature abatement of acid gases from waste incineration. Part II: Comparative life cycle assessment study

Highlights: • Two scenarios of acid gases removal in WTE plants were compared in an LCA study. • A detailed inventory based on primary data has been reported for the production of the new dolomitic sorbent. • Results show that the comparison between the two scenarios does not show systematic differences. • The potential impacts are reduced only if there is an increase in the energy efficiency of the WTE plant. - Abstract: The performances of a new dolomitic sorbent, named Depurcal®MG, to be directly injected at high temperature in the combustion chamber of Waste-To-Energy (WTE) plants as a preliminary stage of deacidification, were experimentally tested during full-scale commercial operation. Results of the experimentations were promising, and have been extensively described in Biganzoli et al. (2014). This paper reports the Life Cycle Assessment (LCA) study performed to compare the traditional operation of the plants, based on the sole sodium bicarbonate feeding at low temperature, with the new one, where the dolomitic sorbent is injected at high temperature. In the latter the sodium bicarbonate is still used, but at lower rate because of the decreased load of acid gases entering the flue gas treatment line. The major goal of the LCAmore » was to make sure that a burden shifting was not taking place somewhere in the life cycle stages, as it might be the case when a new material is used in substitution of another one. According to the comparative approach, only the processes which differ between the two operational modes were included in the system boundaries. They are the production of the two reactants and the treatment of the corresponding solid residues arising from the neutralisation of acid gases. The additional CO{sub 2} emission at the stack of the WTE plant due to the activation of the sodium bicarbonate was also included in the calculation. Data used in the modelling of the foreground system are primary, derived from the experimental tests described in Biganzoli et al. (2014) and from the dolomitic sorbent production plant. The results of the LCA show minor changes in the potential impacts between the two operational modes of the plants. These differences are for 8 impact categories in favour of the new operational mode based on the addition of the dolomitic sorbent, and for 7 impact categories in favour of the traditional operation. A final evaluation was conducted on the potential role of the dolomitic sorbent in enhancing the electric energy production efficiency of the plant, thanks to the better cleaning of the heat exchange surface that can be achieved. If such improvement is accounted for, all the potential impacts are considerably decreased (e.g. the Climate change by 28%), and in the comparison with the traditional operation 17 impact categories out of 19 are reduced.« less
Authors:
 [1] ;  [1] ;  [2] ;  [1]
  1. Politecnico di Milano, Department of Civil and Environmental Engineering, Piazza L. da Vinci 32, 20133 Milano (Italy)
  2. Unicalce S.p.A., R and D Department, Via Tonio da Belledo 30, 23900 Lecco (Italy)
Publication Date:
OSTI Identifier:
22443604
Resource Type:
Journal Article
Resource Relation:
Journal Name: Waste Management; Journal Volume: 35; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; CARBON DIOXIDE; CLIMATIC CHANGE; COMBUSTION; COMBUSTION CHAMBERS; ENERGY EFFICIENCY; FLUE GAS; LIFE CYCLE ASSESSMENT; RESIDUES; SIMULATION; SODIUM CARBONATES; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0400-1000 K; WASTE INCINERATORS