Michel Vedrenne

Emission inventories and modeling requirements for the development of air quality plans. Application to Madrid (Spain).

Modeling is an essential tool for the development of atmospheric emission abatement measures and air quality plans. Most often these plans are related to urban environments with high emission density and population exposure. However, air quality modeling in urban areas is a rather challenging task. As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality exceedances, common in large urban areas across Europe, particularly for NO₂. This also implies that emission inventories must satisfy a number of conditions such as consistency across the spatial scales involved in the analysis, consistency with the emission inventories used for regulatory purposes and versatility to match the requirements of different air quality and emission projection models. This study reports the modeling activities carried out in Madrid (Spain) highlighting the atmospheric emission inventory development and preparation as an illustrative example of the combination of models and data needed to develop a consistent air quality plan at urban level. These included a series of source apportionment studies to define contributions from the international, national, regional and local sources in order to understand to what extent local authorities can enforce meaningful abatement measures. Moreover, source apportionment studies were conducted in order to define contributions from different sectors and to understand the maximum feasible air quality improvement that can be achieved by reducing emissions from those sectors, thus targeting emission reduction policies to the most relevant activities. Finally, an emission scenario reflecting the effect of such policies was developed and the associated air quality was modeled.

Advancements in the design and validation of an air pollution integrated assessment model for Spain

Abstract This paper describes the design and application of the Atmospheric Evaluation and Research Integrated model for Spain (AERIS). Currently, AERIS can provide concentration profiles of NO 2 , O 3 , SO 2 , NH 3 , PM, as a response to emission variations of relevant sectors in Spain. Results are calculated using transfer matrices based on an air quality modelling system (AQMS) composed by the WRF (meteorology), SMOKE (emissions) and CMAQ (atmospheric-chemical processes) models. The AERIS outputs were statistically tested against the conventional AQMS and observations, revealing a good agreement in both cases. At the moment, integrated assessment in AERIS focuses only on the link between emissions and concentrations. The quantification of deposition, impacts (health, ecosystems) and costs will be introduced in the future. In conclusion, the main asset of AERIS is its accuracy in predicting air quality outcomes for different scenarios through a simple yet robust modelling framework, avoiding complex programming and long computing times.

An integrated assessment of two decades of air pollution policy making in Spain: Impacts, costs and improvements.

This paper analyses the effects of policy making for air pollution abatement in Spain between 2000 and 2020 under an integrated assessment approach with the AERIS model for number of pollutants (NOx/NO2, PM10/PM2.5, O3, SO2, NH3 and VOC). The analysis of the effects of air pollution focused on different aspects: compliance with the European limit values of Directive 2008/50/EC for NO2 and PM10 for the Spanish air quality management areas; the evaluation of impacts caused by the deposition of atmospheric sulphur and nitrogen on ecosystems; the exceedance of critical levels of NO2 and SO2 in forest areas; the analysis of O3-induced crop damage for grapes, maize, potato, rice, tobacco, tomato, watermelon and wheat; health impacts caused by human exposure to O3 and PM2.5; and costs on society due to crop losses (O3), disability-related absence of work staff and damage to buildings and public property due to soot-related soiling (PM2.5). In general, air quality policy making has delivered improvements in air quality levels throughout Spain and has mitigated the severity of the impacts on ecosystems, health and vegetation in 2020 as target year. The findings of this work constitute an appropriate diagnosis for identifying improvement potentials for further mitigation for policy makers and stakeholders in Spain.

Implementation of road dust resuspension in air quality simulations of particulate matter in Madrid (Spain)

An evaluation of the concentration levels of Particulate Matter (PM) was carried out in Madrid (Spain) by introducing the emissions from road dust resuspension. Road dust resuspension emission factors (EF) for different types of vehicles were calculated from EPA-AP42, a global resuspension factor of 0.097 g veh-1 km-1 as described in Amato et al. (2010) and a rain-dependent correction factor. With these resuspension EFs, a simulation at street canyon level was performed with the OSPM model without rainfall. Subsequently, a simulation using the CMAQ model was implemented adding resuspension emissions affected by the rain. These data were compared with monitored data obtained from air quality stations. OSPM model simulations with resuspension EFs but without the effect of rainfall improve the PM estimates in about 20 µg m-3 compared to the simulation with default EFs. Total emissions were calculated by adding the emissions estimated with resuspension EFs to the default PM emissions to be used by CMAQ. For the study in the Madrid Area, resuspension emissions are approximately of the same order of magnitude as inventoried emissions. On a monthly scale, rain effects are negligible for resuspension emissions due to the dry weather conditions of Spain. With the exception of April and May, the decrease in resuspension emissions is not greater than 3%. The predicted PM10 concentration increases up to 9 µg m-3 on annual average for each station compared to the same scenario without resuspension. However in both cases, PM10 estimates with resuspension are still underestimating observations. It should be noted that although that accounting for resuspension improves the quality of model predictions, other PM sources (e.g. Saharan dust) were not considered in this study.

Comparison of greenhouse gas emissions from different vehicles covering the entire life cycle

The aim of this paper is to compare the greenhouse gas (GHG) emissions from different types of vehicles, including electric and hybrid, during their entire life cycle. To estimate these emissions, a tool developed by the Technical University of Madrid (UPM), GlobalTRANS, was used. This tool integrates not only Tankto-Wheel emissions (exhaust), but also Well-to-Tank, vehicle manufacturing and disposal emissions. In this study a typical Battery Electric Vehicle (BEV) was compared with traditional internal combustion vehicles, such as gasoline, diesel or LPG cars as well as with hybrid vehicles (electric-gasoline) for the Spanish case. Finally, a sensitivity analysis was done to evaluate the influence of the BEV’s electric consumption on its GHG emissions. For this purpose, emissions were estimated using GlobalTRANS modifying the electric consumption of the vehicle within the range of 100–250 Wh/km, in accordance with BEV catalogue vehicles available in the Spanish market.

Ferrioxalate-Mediated Processes

Abstract Advanced oxidation processes have been successfully applied for wastewater treatment at a laboratory pilot and semi-industrial scale. Sustainable alternatives such as photo-Fenton processes have been scarcely applied due to technical, environmental, and economic barriers. Photo-Fenton intensification with organic complexes appears to be an important alternative to overcome two important disadvantages of Fenton processes, i.e., catalyst regeneration and operation at acidic pH. The addition of organic ligands is critical in improving process performance because it makes operation at circumneutral conditions possible, increases •OH radicals production rate, the regeneration of the iron catalyst, and allows the formation of additional radicals. Although Fenton intensification with organic ligands requires the addition of more reagents, technical and economic advantages such as near neutrality operation, reduction of chemical auxiliaries consumption (acid and base), and reaction time can enhance the environmental performance of Fenton and photo-Fenton processes.

Modeling and model performance evaluation of sewage sludge gasification in fluidized-bed gasifiers using Aspen Plus

ABSTRACT A model was developed to simulate the sewage sludge gasification in an atmospheric fluidised bed gasifier using Aspen Plus. The model here presented was based on the Gibbs free energy minimisation and the restricted equilibrium method was used to calibrate it against previously published experimental data obtained in a lab-scale gasification plant. A sensitivity analysis of the model was carried out by modifying parameters such as the temperature, equivalence ratio (ER) and the steam-to-biomass ratio. The modeled results were in good agreement with the experimental data (especially when air was used as gasifying agent) and reproduced satisfactorily the experimental trends found for the gas composition, the carbon conversion (Xc) and the cold gas efficiency (CGE) under different gasification conditions. Operating at higher temperatures increased the production of H2 and CO, as well as the Xc and the CGE. The increase in ER produced higher Xc, yet the CGE experienced slight changes due to a decrease in the lower heating value of the resulting syngas, as well as the oxidation of combustible gases. The use of air+steam as gasifying agent increased the H2 content of the produced gases but decreased the accuracy of the model. Implications: Gasification is an available alternative to produce energy as well as several raw materials from sewage sludge. The syngas obtained from this technology totally depends on the type of gasifier and the operation conditions, which can be optimized with the help of models. In this work, a relatively simple model was built using ASPEN PLUS. Despite its simplicity, the outputs of the model are in good agreement with experimental results what makes its use interesting for assessing scaling-up possibilities from lab-scale to pilot-scale gasification processes.

Life Cycle Assessment of Road Vehicles

Life cycle assessment (LCA) is a methodology that supports decision making by quantifying the environmental impacts of products, processes or activities. Because of its holistic approach in the description of interactions, LCA is adequate for evaluating the sustainable character of different aspects of the road transport sector. This chapter provides an overview of LCA, its component stages and its application to road vehicles. Special emphasis is given to the processes and types of data that should be taken into consideration when describing the life cycle of vehicles. Finally, a discussion about the suitability of LCA as a complementary tool for addressing current policy issues, especially those related to air pollution, is provided.

Comparison And Assessment Of Two EmissionInventories For The Madrid Region

Emission inventories are databases that aim to describe the polluting activities that occur across a certain geographic domain. According to the spatial scale, the availability of information will vary as well as the applied assumptions, which will strongly influence its quality, accuracy and representativeness. This study compared and contrasted two emission inventories describing the Greater Madrid Region (GMR) under an air quality simulation approach. The chosen inventories were the National Emissions Inventory (NEI) and the Regional Emissions Inventory of the Greater Madrid Region (REI). Both of them were used to feed air quality simulations with the CMAQ modelling system, and the results were compared with observations from the air quality monitoring network in the modelled domain. Through the application of statistical tools, the analysis of emissions at domain and cell level, it was observed that the National Inventory showed better results for describing on–road traffic activities and agriculture, SNAP07 and SNAP10. The accurate description of activities, the good characterization of the vehicle fleet and the correct use of traffic emission factors were the main causes of such a good correlation. On the other hand, the Regional Inventory showed better descriptions for non–industrial combustion (SNAP02) and industrial activities (SNAP03). It incorporated realistic emission factors, a reasonable fuel mix and it drew upon local information sources to describe these activities, while NEI relied on surrogation and national datasets which leaded to a poorer representation. Off–road transportation (SNAP08) was similarly described by both inventories, while the rest of the SNAP activities showed a marginal contribution to the overall emissions.