• Energy Research

9 Figuras, 4 Tablas.-- Material suplementario disponible en línea en la página web del editor. Co-pyrolysis of grape seeds and polystyrene was conducted in a fixed-bed reactor, followed by an analysis of the organic phase for possible further application as a drop-in fuel. Significant positive synergistic effects were found with the addition of polystyrene (5–40 wt%) to the conventional pyrolysis of grape seeds. There was a considerable improvement in the organic phase yield, in particular, reaching values over 80 wt%, markedly higher than those obtained from conventional pyrolysis (61 wt%). Fuel properties of the bio-oil were also upgraded, with a decrease in oxygen content and an increase in the heating value. An organic bio-oil fraction with pH values ranging from 5.4 to 6.2 was obtained, reducing the issues associated with handling bio-oils obtained from common pyrolysis of lignocellulosic biomass, usually ranging pH between 2 and 3. Finally, an increment in the desired compounds, mainly aromatics, was also attained, while at the same time achieving a low content of undesired compounds, such as phenols. It was demonstrated that polystyrene can act as a H2-donor, favoring oligomerization, cyclation and hydrodeoxygenation reactions into aromatic compounds. The authors would like to thank MINECO and FEDER for their financial support (Project ENE2015-68320-R). O.S.P acknowledges the FPI fellowship (BES-2016-077750) funded by MINECO. The authors would also like to thank the Regional Government of Aragon (DGA) for the support provided under the research groups support programme. Peer reviewed

2 figures, 3 tables.-- Supplementary information available.-- © 2014. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/ Production of upgraded bio-oils by catalytic pyrolysis of wood biomass was studied in an auger reactor using low cost materials as catalysts. These materials included several clay minerals (sepiolite, bentonite and attapulgite) and an industrial waste from alumina production, known as red mud. The influence of temperature (400–500 °C) and the effect of catalyst to biomass ratio (3:1–1:6, in weight) were also analysed. A temperature of 450 °C and the lowest catalyst proportion (1:6, in weight) were selected as the most appropriate to aim the pyrolysis for bio-oil production. Catalyst to biomass ratio resulted critical since an excess on catalyst addition seemed to reduce liquid production while char yield increased. Under the selected conditions, the catalysts tested improved the characteristics of the obtained bio-oil as fuel (viscosity, acidity, oxygen content and calorific value). For every catalyst, the viscosity of the organic liquid fraction decreased (up to 34% in case of bentonite) while lower heating value increased (up to 20% in red mud tests). Concerning acidity, sepiolite and red mud produced a decrease in the total acid number (around 29% and 23%, respectively). The stability of the organic fraction after aging test (equivalent to long time storage) was also improved by each catalyst. Authors thank to Spanish MINECO and European FEDER funds for providing support for this work (project CTQ2012-37984-C02-01). Authors also thank to Aragon Regional Government (DGA) and the Caixa Bank for partial financial support (Project GA-LC-015/2011). M. Aznar acknowledges the JAE-Doc Contract provided by European Social Found and CSIC. J.M. López would also like to thank Spanish MICINN and CSIC for funding his Ramon y Cajal contract (RYC-2009-04483) Peer reviewed

© 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/ Sustainable management and disposal alternatives for sewage sludge (SS) should be pursued due to the substantial increment in its global production, as well as due to the raising interest in the renewable energy and synthetic fuels deployment. Since SS present high moisture (>95 % wt.), drying would play an essential role in SS management. In this work, SS pre-treated in a solar-drying facility has been successfully used as feedstock in a 30 kWth bubbling fluidised-bed (BFB) gasification pilot plant operating under Sorption Enhanced Gasification (SEG) conditions, i.e. using CaO as bed material and steam as gasifying agent. The influence of key operating SEG parameters (such as temperature, steam-to-carbon ratio and sorbent-to biomass proportion) in the syngas yield and composition (H2, CO, CO2, CH4, CxHy, H2S, COS, NH3 and tars) has been carefully assessed. As a matter of comparison, steam-oxygen gasification conditions have been also tested in the facility using solar-dried SS as feedstock. The results obtained demonstrate the possibility of producing a syngas with high H2 contents of 70–73 vol% and relatively low CO and CO2 contents (i.e. 2–3 vol% and 8 vol% respectively). This work was partially funded by the project CSIC Biorrefinería TRE2021-03-011. Samuel Moles thanks the grant Margarita Salas funded by the European Union-NextGenerationEU. Isabel Martínez thanks the grant RYC2019-026929-I funded by MCIN/AEI/10.13039/501100011033 and EI ‘‘ESF Investing in your future.” Authors thank also the Regional Government of Aragón under the Research Groups Support Program. Peer reviewed

In order to perform a study of the carcinogenic potential of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene equivalent (BaP-eq) concentration was calculated and modelled by a receptor model based on positive matrix factorization (PMF). Nineteen PAH associated to airborne PM10 of Zaragoza, Spain, were quantified during the sampling period 2001-2009 and used as potential variables by the PMF model. Afterwards, multiple linear regression analysis was used to quantify the potential sources of BaP-eq. Five sources were obtained as the optimal solution and vehicular emission was identified as the main carcinogenic source (35 %) followed by heavy-duty vehicles (28 %), light-oil combustion (18 %), natural gas (10 %) and coal combustion (9 %). Two of the most prevailing directions contributing to this carcinogenic character were the NE and N directions associated with a highway, industrial parks and a paper factory. The lifetime lung cancer risk exceeded the unit risk of 8.7 x 10(-5) per ng/m(3) BaP in both winter and autumn seasons and the most contributing source was the vehicular emission factor becoming an important issue in control strategies.

Three different series of combustion samples (from the ash pan, samples C; from the particulate matter trapped on cyclone, samples PM; and from the finest particulate matter, samples M) have been analyzed looking for any relationship between their PAH content and their ecotoxicity. PAH content was analyzed by synchronous fluorescence spectroscopy. Ecotoxicity of the combustion samples was determined by using the Photobacterium phosphoreum test to assess their toxicity through an ecotoxicity assay. Results obtained are shown and discussed in relation to the PAH content of the samples. Peer reviewed

12 pages, 4 figures, 1 table.-- Work presented at the 19th International Conference on Modelling, Monitoring and Management of Air Pollution, 19 - 21 September 2011, Malta. Particulate matter samples less than or equal to 10 μm (PM10) were collected by using a high-volume air sampler during cold and warm seasons at two different areas in Spain: a rural area which was considered a “non-polluted” area and an urban city, Zaragoza (Spain) in which vehicular traffic and small industries were the potential pollution sources. The PM10 samples were analyzed to determine their organic (polycyclic aromatic hydrocarbons (PAH) by gas chromatographymass spectrometry mass spectrometry) and inorganic (ions: anions and cations, by ionic chromatography and by inductively coupled plasma optical emission spectroscopy (ICP-OES)) composition. Higher PAH and ions concentrations were obtained in the urban area during the cold season when compared to the warm season and these concentrations were always higher than the ones obtained in the rural area. Fuel combustion sources associated with coal, natural gas, vehicular traffic and biomass combustion were the major anthropogenic PM10 pollution sources obtained by principal component analysis (PCA) in the urban area although natural sources associated with marine aerosol were also contributing to this PM10. Cluster analysis corroborated these sources and allowed classifying samples as a function of the meteorological variables, PAH and ion concentrations. Authors would like to thank Aula Dei-CSIC (R. Gracia) for providing the meteorological data, to the Gobierno de Aragón (DGA) for partial financial support, to the Ministry of Science and Innovation (Spain) through the project CGL2009-14113-C02-01 for funding as well as the Fondo Europeo de Desarrollo Regional (FEDER). J.M. López would also like to thank CSIC Spanish Government for his Ramón and Cajal contract.

8 figures, 5 tables. Sorption-enhanced gasification (SEG) is a promising route for the conversion of biomass into synthetic fuels. There are important aspects regarding syngas quality (e.g. tar composition and/or gaseous contaminants such as H2S) that may influence the scaling-up of the process and should be assessed. Experiments were performed in a 30 kWth bubbling fluidised gasifier to evaluate the effect of the feedstock used, temperature, sorbent-to-biomass (S/B) ratio and/or steam excess on such quality aspects. Larger amounts of tars were found for straw, which corresponded to highly stable tars (benzene, toluene, naphthalene and phenanthrene). Temperature, S/B ratio and steam excess favoured tar decomposition, causing the contribution of PAHs to total tar to increase. PAHs and phenol contents were found to be related to and dependant on the temperature and S/B ratio. Elutriated CaO particles reacted with the H2S formed until equilibrium conditions were reached, leading to syngas H2S contents of between 15 and 85 ppm. Sulphur in the syngas represented no more than 15% of the total sulphur introduced into the reactor, whereas 65–85% ended up as CaS with the partially converted sorbent particles leaving the reactor. Authors acknowledge the financial support given by the Spanish Ministry of Science and Innovation, the State Research Agency and the European Funds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE), as well as the Regional Aragon Government (DGA) under the research groups' support programme and the research project LMP178_18. Isabel Martínez thanks also the Spanish Ministry of Science and Innovation for her Ramón y Cajal contract (RYC2019-026929-I). Peer reviewed

5 figures, 5 tables.-- Supplementary information available.-- © 2020. 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 catalytic co-pyrolysis of grape seeds and polystyrene was successfully scaled-up from thermogravimetric analysis to an auger reactor pilot plant. Agricultural residues were co-pyrolyzed with waste polystyrene plastics (up to 20 wt%) using calcium oxide as the catalyst. Particularly, an upgraded organic fraction was produced where synergetic positive effects were observed due to both the presence of plastics and of the CaO catalyst. These effects were mainly reflected in the production of a more deoxygenated and practically dehydrated organic fraction, rich in aromatic compounds and with a remarkable heating value. The synergetic positive effect of these materials is mainly attached to the promotion of the H2 transfer reactions resulting from the scission of polystyrene radicals, and from the decarboxylation and dehydration effects associated with CaO. Moreover, a non-condensable H2-rich gas stream with remarkably low CO2 concentration, proved potentially valuable not only for use in further energetic applications but also as a potential source of synthetic fuels. The great potential of this process in the production of bio-products was, thus, demonstrated in a representative scale. The authors would like to thank MINECO and FEDER for their financial support (Project ENE2015-68320-R). O.S.P acknowledges the FPI fellowship (BES-2016-077750) funded by MINECO. The authors would also like to thank the Regional Government of Aragon (DGA) for the support provided under the research groups support programme. Peer reviewed