Influence of organic and inorganic markers in the source apportionment of airborne PM10 in Zaragoza (Spain) by two receptor models

11 pages, 3 figures, 2 tables.- Published online October 23, 2012Improving knowledge on the apportionment of airborne particulate matter will be useful to handle and fulfill the legislation regarding this pollutant. The main aim of this work was to assess the influence of markers in the source apportionment of airborne PM10, in particular, whether the use of particle polycyclic aromatic hydrocarbon (PAH) and ions provided similar results to the ones obtained using not only the mentioned markers but also gas phase PAH and trace elements. In order to reach this aim, two receptor models: UNMIX and positive matrix factorization were applied to two sets of data in Zaragoza city from airborne PM10, a previously reported campaign (2003-2004) (Callén et al. Chemosphere 76:1120-1129, 2009), where PAH associated to the gas and particle phases, ions and trace elements were used as markers and a long sampling campaign (2001-2009), where only PAH in the particle phase and ions were analyzed. For both campaigns, positive matrix factorization was able to explain a higher number of sources than the UNMIX model. Independently of the sampling campaign and the receptor model used, soil resuspension was the main PM10 source, especially in the warm period (21st March-21st September), where most of the PM10 exceedances were produced. Despite some of the markers of anthropogenic sources were different for both campaigns, common sources associated to different combustion sources (coal, light-oil, heavier-oil, biomass, and traffic) were found and PAH in particle phase and ions seemed to be good markers for the airborne PM10 apportionment. © 2012 Springer-Verlag Berlin Heidelberg.Authors would like to thank Aula Dei-CSIC (R. Gracia) for providing the meteorological data and the CSIC for the Ramón y Cajal contract to J.M.L. Authors would also thank the Spanish Government (MICIIN) for the partial financial support of this work through the contract CGL2009-14113-C02-01 and the E plan for the co-funding.Peer Reviewe

Influence of organic and inorganic markers in the source apportionment of airborne PM10 in Zaragoza (Spain) by two receptor models

11 pages, 3 figures, 2 tablesImproving knowledge on the apportionment of airborne particulate matter will be useful to handle and fulfill the legislation regarding this pollutant. The main aim of this work was to assess the influence of markers in the source apportionment of airborne PM10, in particular, whether the use of particle polycyclic aromatic hydrocarbon (PAH) and ions provided similar results to the ones obtained using not only the mentioned markers but also gas phase PAH and trace elements. In order to reach this aim, two receptor models: UNMIX and positive matrix factorization were applied to two sets of data in Zaragoza city from airborne PM10, a previously reported campaign (2003-2004) (Callén et al. Chemosphere 76:1120-1129, 2009), where PAH associated to the gas and particle phases, ions and trace elements were used as markers and a long sampling campaign (2001-2009), where only PAH in the particle phase and ions were analyzed. For both campaigns, positive matrix factorization was able to explain a higher number of sources than the UNMIX model. Independently of the sampling campaign and the receptor model used, soil resuspension was the main PM10 source, especially in the warm period (21st March-21st September), where most of the PM10 exceedances were produced. Despite some of the markers of anthropogenic sources were different for both campaigns, common sources associated to different combustion sources (coal, light-oil, heavier-oil, biomass, and traffic) were found and PAH in particle phase and ions seemed to be good markers for the airborne PM10 apportionment. © 2012 Springer-Verlag Berlin Heidelberg.Authors would like to thank Aula Dei-CSIC (R. Gracia) for providing the meteorological data and the CSIC for the Ramón y Cajal contract to J.M.L. Authors would also thank the Spanish Government (MICIIN) for the partial financial support of this work through the contract CGL2009-14113-C02-01 and the E plan for the co-funding.Peer Reviewe

An integrated process for the production of lignocellulosic biomass pyrolysis oils using calcined limestone as a heat carrier with catalytic properties

4 figures, 2 tables.-- Supplementary information available.-- © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The production of upgraded bio-oils by an integrated process using a mixture of calcined limestone and sand as a heat carrier with catalytic properties was experimentally studied at pilot scale. The integrated process consisted of two main steps: biomass catalytic pyrolysis in an Auger reactor for bio-oil production and char combustion in a fluidised-bed combustor for heat carrier heating and regeneration. A temperature of 450 °C was fixed as an optimum value to carry out the catalytic pyrolysis step. Temperatures ranging from 700 to 800 °C were assessed in the char combustor. Process simulation demonstrated that solid recirculation from the combustor to the pyrolysis reactor was marginally affected in this temperature range. However, an optimum char combustion temperature of 800 °C was selected from an environmental point of view, since lower polyaromatic emissions were detected whilst NOx emissions were kept under the legislation limits. Under designated conditions, several pyrolysis-combustion cycles were carried out. A moderate deactivation of the catalyst by partial carbonation was found. This fact makes necessary the incorporation of a purge and an inlet of fresh heat carrier in order to maintain the bio-oil quality in the integrated process.Authors thank to Spanish MINECO and European Union FEDER funds for providing support for this work (projects CTQ2012-37984-C02-01 and ENE2015-68320-R).Peer reviewe

Tailored syngas production from the gasification of biogenic waste in the presence of a CO2 sorbent

5 figures, 1 tableSyngas production via steam gasification is one of the thermochemical processes with the greatest potential for obtaining synthetic fuels from a solid fuel, especially indirect gasification in a dual fluidised bed system where the energy needed for gasification is provided by the circulating material from a high temperature secondary reactor. When the circulating material is a CO2 sorbent, a sorption enhanced gasification (SEG) system results where the circulating solid, in addition to the energy provided by sensible heat, supplies additional heat by means of the exothermic carbonation reaction with the CO2 generated from biomass gasification. In the presented work, the SEG process was studied for a biogenic waste material (consisting of the organic fraction of municipal solid waste) in a 30 kWth bubbling fluidised bed reactor using lime as CO2 sorbent. The effect of the main operating variables (temperature, steam-to-carbon (S/C) ratio and sorbent-to-biomass ratio (Ca/C)) on gas quality was assessed. M-modules (M=(H2-CO2)/(CO+CO2)) between 1.2 to almost 4 have been obtained acting on the variables that mostly affect the permanent gas composition, i.e. gasification temperature and/or sorbent-to-biomass ratio.This work has been carried out as part of the European Commission Horizon 2020 Framework Programme project FLEDGED (Grant agreement No. 727600) and the project WASYNG (No. RTI2018-095575-B-100) funded by the Spanish Ministry of Science, Innovation and Universities. Authors thank also the Regional Aragon Government (DGA) for the economic support under the research group’s programme.Peer reviewe

Optimised production of tailored syngas from municipal solid waste (MSW) by sorption-enhanced gasification

8 figures, 5 tablesSorption-enhanced gasification (SEG) is a promising indirect gasification route for the production of synthetic fuels since it allows the H2, CO and CO2 content of the resulting syngas to be adjusted. This SEG process has been successfully demonstrated at pilot scale for lignocellulosic biomass and other agricultural and forest waste products, mainly focusing on H2-rich gas production. Within this work, the potential application of the SEG process to a material derived from municipal solid waste (MSW) as feedstock is experimentally demonstrated in a 30 kWth bubbling fluidised-bed (BFB) gasifier. The influence of the sorbent-to-biomass ratio, steam excess and gasification temperature has been carefully analysed in order to understand their effect on SEG performance. Moreover, main conditions able to affect the resulting syngas composition, specifically in terms of H2, CO and CO2 content, have been indicated. Gasification temperature turned out to be the variable that most influenced syngas composition due to the limiting mechanisms associated with the carbonation of the CaO used as bed material. This operating variable also determined biomass conversion, together with solids residence time in the gasifier, resulting in a wide variation of fixed carbon conversion under the studied conditions. Finally, tar yield and composition were evaluated as a function of temperature and the sorbent-to-biomass ratio used, resulting in tar contents as low as 7 g/Nm3 (dry gas), consisting mainly of 1-ring aromatic compounds.This work has been supported by the European Commission (FLEDGED project, grant agreement No. 727600); the Spanish Ministry of Science and Innovation, the State Research Agency and the European Founds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE); and the Regional Aragon Government (DGA).Peer reviewe

Some inferences on the mechanism of atmospheric gas/particle partitioning of polycyclic aromatic hydrocarbons (PAH) at Zaragoza (Spain)

Gas-particle partitioning of pollutants is an important mechanism determining atmospheric processing and its impact to environmental and human health. In this paper, the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAH) has been studied with the aim of determining the main mechanism of PAH partitioning in Zaragoza (Spain) aerosols. To reach this goal, the ambient concentrations of PAH (gas and particle phase) collected in this city for one year period (2003-2004) have been analyzed. The partitioning between the particle and gas phases was studied according to three different models: the Junge adsorption model, the absorption into the organic matter model using the octanol-air (KOA) partition coefficient and the absorption into the organic matter plus the adsorption onto the soot carbon model using the soot-air (KSA) partition coefficients. Experimental gas/particle partition coefficients (KP) correlated well with the subcooled liquid vapour pressures (P0 L) of PAH but with slopes higher than the expected value of - 1. Experimental Kp values were well fit to the modelled ones when, in addition to absorption into organic matter, adsorption onto the soot carbon was considered. It could be concluded that the main partition mechanism in Zaragoza aerosols was explained by adsorption onto the soot carbon. However, Kp modelled values were affected by the different thermodynamic parameters related to soot types. The influence of the organic matter and elemental carbon fractions on the Kp modelling was also studied. The different particle characteristics, local factors, the presence of non exchangeable fraction and non equilibrium were considered like main keys to explain deviations of the experimental Kp values from predictions according to models.Authors would like to thank the Government of Aragón (DGA) for the grant to M.T.C and the Spanish Government for the JAE doctoral contract to J.M.L and for the Juan de la Cierva contract to M.V.N.Peer reviewe

Seasonal variation of benzo(a) pyrene in the Spanish airborne PM10. Multivariate linear regression model applied to estimate BaP concentrations

The estimation of benzo(a)pyrene (BaP) concentrations in ambient air is very important from an environmental point of view especially with the introduction of the Directive 2004/107/EC and due to the carcinogenic character of this pollutant. A sampling campaign of particulate matter less or equal than 10 microns (PM10) carried out during 2008-2009 in four locations of Spain was collected to determine experimentally BaP concentrations by gas chromatography-mass spectrometry-mass spectrometry (GC/MS/MS). Multivariate linear regression models (MLRM) were used to predict BaP air concentrations in two sampling places, taking PM10 and meteorological variables as possible predictors. The model obtained with data from two sampling sites (all sites model) (R2=0.817, PRESS/SSY=0.183) included the significant variables like PM10, temperature, solar radiation and wind speed and was internally and externally validated. The first validation was performed by cross validation and the last one by BaP concentrations from previous campaigns carried out in Zaragoza from 2001-2004. The proposed model constitutes a first approximation to estimate BaP concentrations in urban atmospheres with very good internal prediction (Q2CV=0.813, PRESS/SSY=0.187) and with the maximal external prediction for the 2001-2002 campaign (Q2ext=0.679 and PRESS/SSY=0.321) versus the 2001-2004 campaign (Q2ext=0.551, PRESS/SSY=0.449).Peer reviewe

Apportionment of the airborne PM10 in Spain. Episodes of potential negative impact for human health

9 pages, 5 figures, 4 tables.The particulate matter with an aerodynamic diameter less than or equal to 10 and 2.5 microns respectively (PM10 and PM2.5) constitutes one of the main air pollutants, which is currently regulated in Europe through Directive 2008/50/EC due to its proven harmful effects on human health. In this paper, the airborne PM10 samples collected in Zaragoza city during 2001-2009 were apportioned by statistical tools based on principal component analysis with absolute principal component scores (PCA-APCS). PM10 samples were characterized regarding their concentrations of polycyclic aromatic hydrocarbons (PAH) and water-soluble ions. PAH were analyzed by gas chromatography-mass spectrometry-mass spectrometry detection (GC-MS-MS) and ions were analyzed by ion chromatography. A total of five factors were identified by PCA-APCS corresponding to different anthropogenic and natural sources. This work was focused on analyzing in more detail those samples involving higher negative impact on human health, in particular, PM10 samples exceeding the daily PM10 limit value of 50 μg m -3 according to Directive 2008/50/EC and samples with concentrations of benzo[a]pyrene (BaP) higher than the upper assessment threshold (BaP > 0.6 ng m -3) established by the Directive 2004/107/EC. Most of the exceedances of the daily PM10 limit value were associated with direct and indirect North-African long-range transport. During these exceedances, it was observed that anthropogenic pollution sources slightly decreased with regard to the natural sources. This indicated that episodes of high PM10 could have a natural origin associated with long-range transport from the African continent. On the contrary, those exceedances with regional contribution and samples with BaP concentrations higher than 0.6 ng m -3 showed an important contribution of anthropogenic pollution sources increasing their negative impact on human health.Authors would like to thank Aula Dei-CSIC (R. Gracia) for providing the meteorological data as well as the Ministry of Science and Innovation (Spain)(MICIIN) and the E-Plan for partial financial support through the project CGL2009-14113-C02-01. J.M. López would also like to thank the MICYT for his Ramón y Cajal contract. We also acknowledge the NOAA Air Data Resources Laboratory and the Australia’s Bureau of Meteorology for the HYSPLIT model.Peer Reviewe

Characterization of PM10-bound polycyclic aromatic hydrocarbons in the ambient air of Spanish urban and rural areas

Accepted 16th November, 2010.Urban areas constitute major pollution sources due to anthropogenic activities located in these areas. Among the legislated air pollutants, the particulate matter with an aerodynamic diameter less than or equal to 10 microns (PM10) and polycyclic aromatic hydrocarbons (PAH) are controlled under Directive 2008/50/EC and Directive 2004/107/EC, respectively due to their adverse health effects. A study was carried out at four urban and rural Spanish areas during the warm and cold seasons in 2008-2009 to quantify 19 PAH associated with the atmospheric PM10 by gas chromatography-mass spectrometry-mass spectrometry detection (GC-MS-MS) with the internal standard method. The particle-bound composition of the analysed PAH was 5 and 10 times greater in industrial and urban areas, respectively when compared to those measured in rural areas. The highest PAH concentrations during the cold period were possibly due to the additional contribution of domestic heating sources and meteorological conditions such as low temperature and solar irradiation. The use of molecular diagnostic ratios indicated that the possible, major PAH pollution sources in the most polluted areas were pyrogenic sources, mainly attributed to petroleum combustion sources (motor vehicle emissions and crude oil combustion). Petrogenic sources related to evaporative emissions also seemed to contribute in the most polluted area during the warm period. Those dates with high carcinogenic character according to the benzo(a)pyrene equivalent (BaP-eq) were also possibly attributed to petroleum combustion sources. © The Royal Society of Chemistry 2011.Authors would like to thank Aula Dei-CSIC (R. Gracia), the Government of Aragon (DGA), the Fondo Social Europeo de Desarrollo Regional and the Ministry of Science and Innovation for supporting the project CGL2009-14113-C02-01 and the Ramón y Cajal contract of J.M.L.Peer Reviewe

Advanced bio-fuels for biorefineries: incorporation of waste tires and calcium-based catalysts to the pyrolysis of biomass

Work presented at the ICRRB 2018: International Conference on Renewable Resources and Biorefineries, Toronto, Canada, June 21-22, 2018.The appropriate use of renewable sources emerges as a decisive point to minimize the environmental impact caused by fossil fuels use. Particularly, the use of lignocellulosic biomass becomes one of the best promising alternatives since it is the only carbon-containing renewable source that can produce bioproducts similar to fossil fuels and it does not compete with food market. Among all the processes that can valorize lignocellulosic biomass, pyrolysis is an attractive alternative because it is the only thermochemical process that can produce a liquid biofuel (bio-oil) in a simple way and solid and gas fractions that can be used as energy sources to support the process. However, in order to incorporate bio-oils in current infrastructures and further process in future biorefineries, their quality needs to be improved. Introducing different low-cost catalysts and/or incorporating different polymer residues to the process are some of the new, simple and low-cost strategies that allow the user to directly obtain advanced bio-oils to be used in future biorefineries in an economic way. In this manner, from previous thermogravimetric analyses, local agricultural wastes such as grape seeds (GS) were selected as lignocellulosic biomass while, waste tires (WT) were selected as polymer residue. On the other hand, CaO was selected as low-cost catalyst based on previous experiences by the group. To reach this aim, a specially-designed fixed bed reactor using N₂ as a carrier gas was used. This reactor has the peculiarity to incorporate a vertical mobile liner that allows the user to introduce the feedstock in the oven once the selected temperature (550 ºC) is reached, ensuring higher heating rates needed for the process. Obtaining a well-defined phase distribution in the resulting bio-oil is crucial to ensure the viability to the process. Thus, once experiments were carried out, not only a well-defined two layers was observed introducing several mixtures (reaching values up to 40 wt.% of WT) but also, an upgraded organic phase, which is the one considered to be processed in further biorefineries. Radical interactions between GS and WT released during the pyrolysis process and dehydration reactions enhanced by CaO can promote the formation of better-quality bio-oils. The latter was reflected in a reduction of water and oxygen content of bio-oil and hence, a substantial increase of its heating value and its stability. Moreover, not only sulphur content was reduced from solely WT pyrolysis but also potential and negative issues related to a strong acidic environment of conventional bio-oils were minimized due to its basic pH and lower total acid numbers. Therefore, acidic compounds obtained in the pyrolysis such as CO₂-like substances can react with the CaO and minimize acidic problems related to lignocellulosic bio-oils. Moreover, this CO₂ capture promotes H₂ production from water gas shift reaction favoring hydrogen-transfer reactions, improving the final quality of the bio-oil. These results show the great potential of grapes seeds to carry out the catalytic co-pyrolysis process with different plastic residues in order to produce a liquid bio-oil that can be considered as a high-quality renewable vector