Enhanced modelling of heterogeneous gas–solid reactions in acid gas removal dry processes

Antonioni, Giacomo; Pozzo, Alessandro Dal; Guglielmi, Daniele; Tugnoli, Alessandro; Cozzani, Valerio

doi:10.1016/j.ces.2016.03.009

Cited by 22 publications

(14 citation statements)

References 51 publications

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“…1b). Various empirical models were used to account for these changes including a shrinking-core model 28 , a Crystallization and Fracture modeling framework 29 , a kinetic model 30 , and a surface solvation model 31 . None of these processes have been studied extensively under stratospheric conditions.…”

Section: Resultsmentioning

confidence: 99%

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

Dai

Weisenstein

Keutsch

et al. 2020

Commun Earth Environ

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Stratospheric solar geoengineering (SG) would impact ozone by heterogeneous chemistry. Evaluating these risks and methods to reduce them will require both laboratory and modeling work. Prior model-only work showed that CaCO3 particles would reduce, or even reverse ozone depletion. We reduce uncertainties in ozone response to CaCO3 via experimental determination of uptake coefficients and model evaluation. Specifically, we measure uptake coefficients of HCl and HNO3 on CaCO3 as well as HNO3 and ClONO2 on CaCl2 at stratospheric temperatures using a flow tube setup and a flask experiment that determines cumulative long-term uptake of HCl on CaCO3. We find that particle ageing causes significant decreases in uptake coefficients on CaCO3. We model ozone response incorporating the experimental uptake coefficients in the AER-2D model. With our new empirical reaction model, the global mean ozone column is reduced by up to 3%, whereas the previous work predicted up to 27% increase for the same SG scenario. This result is robust under our experimental uncertainty and many other assumptions. We outline systematic uncertainties that remain and provide three examples of experiments that might further reduce uncertainties of CaCO3 SG. Finally, we highlight the importance of the link between experiments and models in studies of SG.

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Section: Resultsmentioning

confidence: 99%

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

Dai

Weisenstein

Keutsch

et al. 2020

Commun Earth Environ

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“…DSI has the objective to neutralize the acid pollutants HCl and SO 2 (typically present in the raw flue gas of WtE plants in concentrations of 700–1200 and 20–100 mg/Nm 3 , respectively). Further details on the process are reported in the literature. − …”

Section: Methodsmentioning

confidence: 99%

CO₂ Uptake Potential of Ca-Based Air Pollution Control Residues over Repeated Carbonation–Calcination Cycles

et al. 2018

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The operation of dry processes for acid gas removal from flue gas in waste-to-energy plants based on the use of calcium hydroxide as a solid sorbent generates a solid waste stream containing fly ash, unreacted calcium hydroxide, and the products of its reaction with acid pollutants in the flue gas (HCl and SO2). To date, the fate of the solid waste stream is to be put into a landfill in the absence of commercially viable recycling approaches. The present study investigates the potential of these residues as CO2 sorbents in the calcium looping process. Samples collected in different waste-to-energy plants were tested over multiple carbonation–calcination cycles, comparing their performance to that of limestone. Although inferior, the CO2 sorption capacity of the residues resulted in values comparable to that of limestone and that steadily increased for a significant number of cycles. This peculiar behavior was attributed to the presence of a chlorinated phase, which enhances the CO2 uptake in the diffusion-controlled stage of carbonation by reducing the product layer resistance to CO2 diffusion. No significant release of acid gases was observed at the characteristic temperatures of calcium looping carbonation.

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“…The reference dry acid gas treatment technology considered here is a two-stage system, based on the injection and subsequent filtering of calcium hydroxide, Ca(OH) 2 , and sodium bicarbonate, NaHCO 3 , respectively, in the 1st and 2nd treatment stage (Figure 4). These sorbents react with the acid pollutants via gas-solid reactions [77]. The spent solid residues are collected by the fabric filters.…”

Section: Modeling and Scale-up Of The Processesmentioning

confidence: 99%

Integrating Life Cycle Inventory and Process Design Techniques for the Early Estimate of Energy and Material Consumption Data

et al. 2018

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Life cycle assessment (LCA) is a powerful tool to identify direct and indirect environmental burdens associated with products, processes and services. A critical phase of the LCA methodology is the collection of representative inventory data for the energy and material streams related to the production process. In the evaluation of new and emerging chemical processes, measured data are known only at laboratory scale and may have limited connection to the environmental footprint of the same process implemented at industrial scale. On the other hand, in the evaluation of processes already established at commercial scale, the availability of process data might be hampered by industrial confidentiality. In both cases, the integration of simple process design techniques in the LCA can contribute to overcome the lack of primary data, allowing a more correct quantification of the life cycle inventory. The present paper shows, through the review of case study examples, how simplified process design, modeling and simulation can support the LCA framework to provide a preliminary estimate of energy and material consumption data suitable for environmental assessment purposes. The discussed case studies illustrate the implementation of process design considerations to tackle availability issues of inventory data in different contexts. By evidencing the case-specific nature of the problem of preliminary conceptual process design, the study calls for a closer collaboration of process design experts and life cycle analysts in the green development of new products and processes.

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Enhanced modelling of heterogeneous gas–solid reactions in acid gas removal dry processes

Cited by 22 publications

References 51 publications

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

CO₂ Uptake Potential of Ca-Based Air Pollution Control Residues over Repeated Carbonation–Calcination Cycles

Integrating Life Cycle Inventory and Process Design Techniques for the Early Estimate of Energy and Material Consumption Data

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Enhanced modelling of heterogeneous gas–solid reactions in acid gas removal dry processes

Cited by 22 publications

References 51 publications

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

Experimental reaction rates constrain estimates of ozone response to calcium carbonate geoengineering

CO2 Uptake Potential of Ca-Based Air Pollution Control Residues over Repeated Carbonation–Calcination Cycles

Integrating Life Cycle Inventory and Process Design Techniques for the Early Estimate of Energy and Material Consumption Data

Contact Info

Product

Resources

About

CO₂ Uptake Potential of Ca-Based Air Pollution Control Residues over Repeated Carbonation–Calcination Cycles