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The increasing use of intensive agricultural practices can lead to damaging consequences for the atmosphere through enhanced emissions of air pollutants. However, there are few direct measurements of the surface-atmosphere exchange of trace gases and water–soluble aerosols over agricultural grassland, particularly of reactive nitrogen compounds. In this study, we present measurements of the concentrations, fluxes and deposition velocities of the trace gases HCl, HONO, HNO3, SO2 and NH3, and their associated water-soluble aerosol counterparts Cl-, NO2-, NO3-, SO42-, NH4+ as determined hourly for one month in May–June 2016 over agricultural grassland near Edinburgh, UK, pre- and post- fertilisation. Measurements were made using the Gradient of Aerosols and Gases Online Registration (GRAEGOR) wet–chemical two–point gradient instrument. Emissions of NH3 peaked at 1460 ng m-2 s-1 three hours after fertilisation, with an emission of HONO peaking at 4.92 ng m-2 s-1 occurring five hours after fertilisation. Apparent emissions of NO3- aerosol were observed after fertilisation which, coupled with a divergence of HNO3 deposition velocity (Vd) from its theoretical maximum value, suggested the reaction of emitted NH3 with atmospheric HNO3 to form ammonium nitrate aerosol. The use of the conservative exchange fluxes of tot-NH4+ and tot-NO3- indicated net emission of tot-NO3-, implying a ground source of HNO3 after fertilisation. Daytime concentrations of HONO remained above the detection limit (30 ng m-3) throughout the campaign, suggesting a daytime source for HONO at the site. Whilst the mean Vd of NH4+ was with 0.93 mm/s in the range expected for the accumulation mode, the larger average Vd for Cl- (3.65 mm/s), NO3- (1.97 mm/s), SO42- (1.89 mm/s) reflected the contribution of a super-micron fraction and decreased with increasing PM2.5/PM10 ratio (a proxy measurement for aerosol size), providing evidence – although limited by the use of a proxy for aerosol size – of a size-dependence of aerosol deposition velocity for aerosol chemical compounds, which has been suggested from process orientated models of aerosol deposition.

International audience; Chemical absorption with alkanolamines processes are commonly applied for natural gas purification. The knowledge of CO 2 , H 2 S, hydrocarbons and mercaptans solubilities in aqueous alkanolamine solutions is important in acid gas removal process simulation and design. In previous works, alkanes, aromatics and mercaptans solubilities in different aqueous alkanolamine solutions have been successfully represented by using the PR-CPA EoS. In this work, the PR-CPA EoS with a pseudo-chemical reaction approach is developed and applied to describe the solubility of acid gases in aqueous alkanolamines solutions. The results are in good agreement with a wide range of experimental data. Other relevant properties such as water content, electrolytes speciation and enthalpy of absorption are accurately predictd by PR-CPA EoS.

Gaseous and particulate emissions from the combustion of coal have been associated with adverse effects on human and environmental health, and have for that reason been subject to regulation by federal and state governments. Recent regulations by the United States Environmental Protection Agency have further restricted the emissions of acid gases from electricity generating facilities and other industrial facilities, and upcoming deadlines are forcing industry to consider both pre- and post-combustion controls to maintain compliance. As a result of these recent regulations, dry sorbent injection of trona to remove acid gas emissions (e.g. HCl, SO2, and NOx) from coal combustion, specifically 90% removal of HCl, was the focus of the current investigation. Along with the measurement of HCl, SO2, and NOx, measurements of particulate matter (PM), elemental (EC), and organic carbon (OC) were also accomplished on a pilot-scale coal-fired combustion facility. Gaseous and particulate emissions from a coal-fired combustor burning bituminous coal and using dry sorbent injection were the focus of the current study. From this investigation it was shown that high levels of trona were needed to achieve the goal of 90% HCl removal, but with this increased level of trona injection the ESP and BH were still able to achieve greater than 95% fine PM control. In addition to emissions reported, measurement of acid gases by standard EPA methods were compared to those of an infrared multi-component gas analyzer. This comparison revealed good correlation for emissions of HCl and SO2, but poor correlation in the measurement of NOx emissions.

Izdvajanje kiselih plinova iz prirodnog plina trenutno je jedan od globalnih problema svih proizvođača plina. Razni projekti proizvodnje prirodnog plina širom svijeta susreću se sa sve većim izazovima u izdvajanju kiselih plinova, što kreće od povećanja koncentracija kiselih plinova do sve strožih tržišnih specifikacija i emisijskih standarda u zaštiti okoliša. Zbog toga je u proizvodnji prirodnog plina od velike važnosti učinkovito i jednostavno izdvajanje CO2, H2O, H2S, RSH, COS i organskih sulfida. Procesi koji koriste fizička otapala za izdvajanje kiselih plinova, kao što su Selexol, Purisol, Rectisol i fluorosolventni proces postaju sve popularniji, naročito u postrojenjima za uplinjavanje ugljena. U slučaju visokih koncentracija kiselih plinova u prirodnom plinu, prednost se daje primjeni procesa koji koriste fizička otapala. U ovom su radu opisani jednostavni procesi izdvajanja kiselih plinova iz prirodnog plina koji koriste fizička otapala i procesi s miješanim fizičkim i kemijskim otapalima., Removal of acid gases from natural gas is currently a global issue for gas producers. Various gas development projects face growing challenges from increasingly contaminated resources and tightening sales specifications to stricter environmental standards. It is there for important to produce natural gas as efficiently possible, while removing CO2, H2O, H2S, RSH, COS and organic sulfides. Physical solvents such as Selexol, Purisol, Rectisol and Fluor Solvent are becoming increasingly popular as gas treating solvents, especially for coal gasification applications. Physical solvents tend to be favored over chemical solvents when the concentration of acid gases is very high. In this thesis simple physical solvent processes and mixed physical/chemical solvent processes are described.

In this study, the physical solubilities of CO2 in several amine solutions at different concentrations and pressures were determined using the nitrous oxide N2O analogy. The solubilities of N2O in four aqueous amine solutions, including Monoethanolamine (MEA), Diethanolamine (DEA), Diethylenetriamine (DETA), and Tetraethylenepentamine (TEPA) were determined experimentally at different concentrations and pressures ranging from 1 to 4 kmol/m3 and 101.3-405.3 kPa, respectively. The solubility of N2O and CO2 for a few amines were compared with data available in the literature. The experimental data agreed well with those published in the literature. The CO2 solubility values obtained experimentally as well as other values from the literature were correlated to the concentrations of the amino groups in the amine. The physical solubility of CO2 was found to be inversely proportional to the number of amino groups in the amine. The simple correlation can give reasonable predictions with an average error of less than 10% for CO2 solubility at 298 K and 101.3 kPa. 2016 Elsevier B.V. The authors gratefully acknowledge the financial support provided by the Japan Cooperation Center, Petroleum (JCCP) and the technical support of JX Nippon Research Institute Co., Ltd (JX-NRI). Scopus

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 LCA 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 CO2 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.

In recent years, several waste-to-energy plants in Italy have experienced an increase of the concentration of acid gases (HCl, SO2 and HF) in the raw gas. This is likely an indirect effect of the progressive decrease of the amount of treated municipal waste, which is partially replaced by commercial waste. The latter is characterised by a higher variability of its chemical composition because of the different origins, with possible increase of the load of halogen elements such as chlorine (Cl) and fluorine (F), as well as of sulphur (S). A new dolomitic sorbent was then tested in four waste-to-energy plants during standard operation as a pre-cleaning stage, to be directly injected at high temperature in the combustion chamber. For a sorbent injection of about 6 kg per tonne of waste, the decrease of acid gases concentration downstream the boiler was in the range of 7-37% (mean 23%) for HCl, 34-95% (mean 71%) for SO2 and 39-80% (mean 63%) for HF. This pre-abatement of acid gases allowed to decrease the feeding rate of the traditional low temperature sorbent (sodium bicarbonate in all four plants) by about 30%. Furthermore, it was observed by the plant operators that the sorbent helps to keep the boiler surfaces cleaner, with a possible reduction of the fouling phenomena and a consequent increase of the specific energy production. A preliminary quantitative estimate was carried out in one of the four plants.

International audience; This study focuses on the chemical compositions of volcanic gases and aerosols emitted by Lascar volcano (Northern Chile). The sustained volcanic plume was sampled in April 2009, April 2011 and November 2012 through filter packs and analyzed for major gaseous species (SO2, HCl, and HF) and trace elements. During fieldwork, SO2 flux measurements were also performed by UV spectrometry (DOAS). The Lascar volcano is a significant and sustained emitter of SO2 (between 150 and 940 t/d), HCl (between 170 t/d and 210 t/d) and HF (up to 100 t/d). Combining the SO2-normalized trace element concentrations and the SO2 emission rates, we evaluate that the quiescent degassing of Lascar is an important local source of trace metals to the atmosphere with contributions to global volcanic fluxes generally less than 2%.Our data were used to infer the origin of the gas emitted at Lascar. Two major degassing sources were identified: a deep magmatic reservoir and a shallow hydrothermal system. The variable interaction between these two sources is the most likely scenario for explaining the compositional ranges in acid gases but also in a volatile and fluid–mobile trace element such as B. These variations are related to changes in volcanic activity: an extensive interaction between the hot ascending magmatic gases and the shallow aquifer occurred in 2009, possibly due to a long period of quiescence, before magmatic activity renewed in 2011 and 2012. Our study highlights, therefore, that filter-pack measurements may be used to study changes in subsurface processes that probably play a key role in triggering volcanic eruptions.

Direct analysis techniques have greatly simplified analytical methods used to monitor analytes at trace levels in air samples. One of these methods, Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS), has proven to be particularly effective because of its speed and ease of use. The range of analytes accessible using the SIFT-MS technique has been extended by this work as it introduces five new negatively charged reagent ions (O−, OH−, O2−, NO2−, and NO3−) from the same microwave powered ion source of moist air used to generate the reagent ions traditionally used (H3O+, NO+, and O2+). Results are presented using a nitrogen carrier gas showing the linearity with concentration of a number of analytes not readily accessible to positive reagent ions (CO2 from ppbv to 40,000 ppmv, sulfuryl fluoride and HCl). The range of analytes open to the SIFT-MS technique has been extended and selectivity enhanced using negative reagent ions to include CCl3NO2, SO2F2, HCN, CH3Cl, PH3, C2H4Br2, HF, HCl, SO2, SO3, and NO2.

This summary is a project of the Institute for Community Engaged Scholarship (ICES) at the University of Guelph, with project partners: the Business Development Office (BDO), SPARK Program at the University of Guelph, and Knowledge Mobilization Unit at York University. This project is part of the Pan-Canadian Research Impact Network. http://csahs.uoguelph.ca/pps/Clear_Research Commercial chicken facilities release pollutants into the environment. These pollutants can be harmful to human health and the environment. The researchers determined the average emission rates of pollutants from the chicken houses. The emission rates were influenced by the chickens’ activity and the season. As the chickens grew, the pollutant emissions increased (except for ammonia). Project support by Agri-Food and Rural Link, Mobilizing Agri-food and Rural Research Knowledge. A program of the OMAFRA-U of G Partnership. http://www.uoguelph.ca/research/omafra/ partnership/KTT_and_IP.shtml

This summary is a project of the Institute for Community Engaged Scholarship (ICES) at the University of Guelph, with project partners: the Business Development Office (BDO), SPARK Program at the University of Guelph, and Knowledge Mobilization Unit at York University. This project is part of the Pan-Canadian Research Impact Network. http://csahs.uoguelph.ca/pps/Clear_Research Commercial broiler chicken facilities release pollutants into the atmosphere. Broiler chickens are chickens raised specifically for meat production. There are some variables (data) that are typically known at broiler chicken facilities. The researchers used math models to develop correlations between these variables and pollutant emissions. These can be used to predict the emissions of pollutants. Project support by Agri-Food and Rural Link, Mobilizing Agri-food and Rural Research Knowledge. A program of the OMAFRA-U of G Partnership. http://www.uoguelph.ca/research/omafra/ partnership/KTT_and_IP.shtml

International audience; This paper gives the first step of the development of a rigorous multicomponent reactive separation model. Such a model is highly essential to further the optimization of acid gases removal plants (CO2 capture, gas treating, etc.) in terms of size and energy consumption, since chemical solvents are conventionally used.Firstly, two main modelling approaches are presented: the equilibrium-based and the rate-based approaches.Secondly, an extended rate-based model with rigorous modelling methodology for diffusion-reaction phenomena is proposed. The film theory and the generalized Maxwell-Stefan equations are used in order to characterize multicomponent interactions. The complete chain of chemical reactions is taken into account. The reactions can be kinetically controlled or at chemical equilibrium, and they are considered for both liquid film and liquid bulk.Thirdly, the method of numerical resolution is described. Coupling the generalized Maxwell-Stefan equations with chemical equilibrium equations leads to a highly non-linear Differential-Algebraic Equations system known as DAE index 3. The set of equations is discretized with finite-differences as its integration by Gear method is complex. The resulting algebraic system is resolved by the Newton- Raphson method.Finally, the present model and the associated methods of numerical resolution are validated for the example of esterification of methanol. This archetype non-electrolytic system permits an interesting analysis of reaction impact on mass transfer, especially near the phase interface. The numerical resolution of the model by Newton-Raphson method gives good results in terms of calculation time and convergence. The simulations show that the impact of reactions at chemical equilibrium and that of kinetically controlled reactions with high kinetics on mass transfer is relatively similar. Moreover, the Fick’s law is less adapted for multicomponent mixtures where some abnormalities such as counter-diffusion take place.

International audience; In this work, vapor-liquid equilibrium (VLE) measurements of propyl mercaptan (PM) in pure water were performed at three different temperatures, (303, 323, and 365) K, with a pressure variation from (1 to 8) MPa. The total system pressure was maintained by CH4. The inlet mole fraction of propyl mercaptan in all experiments was the same, around 4.5 center dot 10(-4) in the liquid phase. The objective was to provide experimental VLE data points of the propyl mercaptan + methane + water system for modeling since there is a lack of available data. These data will allow the industrial modeling of sulfur emission. The thermodynamic model used for the description of VLE is the extended UNIQUAC model. The model parameters are valid in the temperature range similar to the measured data and a pressure range up to 8 MPa.

We have performed molecular dynamics simulations at constant temperature and pressure to calculate the solubility of carbon dioxide (CO2) and hydrogen sulfide (H2S) in water. The solubility of gases in water is important in several technological problems, in particular in the petroleum industry. The calculated liquid densities as function of temperature are in good agreement with experimental data. The results at the liquid-vapor equilibrium show that at low temperatures there is an important amount of gases at the interface. The adsorption of gases in the liquid phase decreases as temperatures increases.

National audience; Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the chimney such as condensation and dissolution of acid gases (in this particular case, sulphur dioxide SO2). The production of energy from fossil fuels (coal, petroleum, natural gas, etc.) brings about the emission of gas containing sulphur compounds (SO2, SO3) as well as chlorine and fluorine compounds. To avoid this atmospheric pollution and its harmful effects (acid rains, impact on the health) due to hydrochloric, sulphuric and hydrofluoric acids produced in the presence of air, it is necessary to steam these flue gases. Nevertheless, a considerable quantity of residual acid gases remains in the gas discharge which also contains large amounts of water vapour. Thus, condensation may occur and by the way an acid attack of the internal cladding of the chimney. This results in high costs of maintenance and a reduction of their structural stability. The knowledge of the phenomena of heat and mass transfer during the condensation of these acid gases in chimney is essential for their conception and materials choice.