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The textile industry generates millions of tons of waste annually, making this sector one of the most polluting in the world. The objective of this research was to study the energy potential of three industrial textile wastes of vegetable and animal origin: CW (card waste), SFW (short fibre waste) and W (wool), using conventional and flash pyrolysis at 500 °C and 750 °C. CW and SFW thermogravimetric profiles were very different from W. In general, the bio-oil yield was higher in the conventional and in the low-temperature flash pyrolysis (up to 55 %). The gas obtained by flash pyrolysis at 750 °C has higher flue gas content and lower CO2 content so their high heating value (HHV) is higher (up to 15.34 MJ/kg). Bio-oils obtained by flash pyrolysis at high temperature stood out for their higher HHV (>30 MJ/kg), with the highest value (34.15 MJ/kg) obtained from SFW waste. Both low temperature flash pyrolysis and conventional pyrolysis produce bio-oils that contain aromatic (35–48 %) and non-aromatic (18–34 %) organic compounds. Additionally, they have high levels of phenols and benzenes. High-temperature flash pyrolysis bio-oils are mainly composed of polycyclic aromatic hydrocarbons. The textile samples are suitable for an energetic valorisation, highlighting the best SWF behaviour.

Residual biomass is a valuable and growing by-product, but often underutilized. This research aims to investigate the possible strategies for the energetic valorisation of agri-food industry wastes: grape seed and chestnut shell. Pyrolysis thermal process was the selected for this work. Applied to biomass, pyrolysis is a promising method for the simultaneous production of biochar, bio-oil, and gas. Two different pyrolysis processes were conducted: conventional pyrolysis at 750 °C and flash pyrolysis at 750 °C and 850 °C. Flash pyrolysis yielded superior product properties compared to conventional pyrolysis. The gas obtained through flash pyrolysis presented a four-fold higher high heating value due to increased CH4 and H2 content. Bio-oil contains over 90% of polycyclic aromatic hydrocarbons, and calorific value reached up to 32 MJ kg−1 for grape seed, which is 7% more than bioethanol HHV. Biochar can be used both as fuel or as activated carbon precursor due to its high carbon content (91%). Calorific value of chestnut shell biochar (32.7 MJ kg−1), comparable to mineral coals, increased by 72% with respect to the value of this untreated raw material. This work approved the potential of flash pyrolysis as a method to process biomass wastes in a renewable energy scenario.

Green and Sustainable activated carbons were obtained by one-step alkaline chemical activation process using a food industry lignocellulosic waste (pomegranate peels) as precursor. A non-harmful activating agent (alkali carbonate) was used, a more sustainable alternative to alkali hydroxides. The pomegranate peels-based activated carbons present high carbon content (>94%), low ash content (<0.5%) and significant nitrogen content (>1.0%); this last value is important because they can be highly effective CO2 adsorbents with the aim of improving biogas for renewable energy production. The activated carbons obtained were essentially microporous materials (micropore volume >82%), with BET specific surface area up to 1860 m2/g and total pore volume up to 0.879 cm3/g. These adsorbents were very efficient materials to retain CO2 at high pressure with an adsorption capacity similar or superior to experimental and commercial activated carbons. The CO2 adsorption capacity increased mainly with increasing activation temperature, the highest value being 717 mg/g at 3 MPa and 25 °C. Ultramicropores were very efficient in the CO2 and CH4 adsorption at low pressure while large micropores and small mesopores governed the high-pressure sorption behavior. These materials had negligible H2 adsorption capacity which makes them useful for separating gas mixtures in order to obtain pure H2.

Bio-derived magnetic activated carbons from industrial chestnut shell waste have been obtained through a novel, optimized and sustainable methodology where impregnation, pyrolysis, acid washing or other intermediate steps commonly used in the activation process were eliminated saving time, energy and costs. The resulting materials (MACs) were obtained at 220-800 °C showed interesting properties: textural (SBET up to 568 m2 g-1) and magnetic (different iron species developed), depending on the activation temperature employed. Data showed outstanding results when MACs were tested for Hg removal in pollution emissions at 150 °C in lab-scale device. In MACs obtained at 500-600 °C, where the highest concentration of magnetite was found, the best Hg adsorption capacity was achieved, while it decreased when metallic iron or iron carbides were present (MACs obtained at 800 °C). Moreover, the difference of Hg0 removal/adsorption in N2+O2 and Simulated Flue Gas atmosphere between MACs obtained at 500 and 600 °C pointed out the influence on Hg removal of additional parameters, as surface chemistry and the existence of sulfur or chloride. The determination of Hg species in post-retention solids confirmed the mercury oxidation by high-valence iron ions (Fe3+) and the involvement of physisorption and chemisorption processes for the gas-solid interaction mechanism.

The preparation of graphene materials from biomass resources is still a challenge, even more so if they are going to be employed as supports for electrocatalysts for water splitting. Herein, we describe the preparation and characterization of graphene oxides (GOs) from solid macroalgae waste obtained after processing an agar–agar residue. The structural and morphological characterization of the obtained GO confirm the presence of a lamellar material that is composed of few layers with an increased number of heteroatoms (including nitrogen) if compared with those observed in a GO obtained from graphite (reference). Three-dimensional electrodes were prepared from these GOs by depositing them onto a fibrous carbon paper, followed by electrodeposition of the catalyst, NiFe. The electrocatalytic performance of these hybrid systems for the oxygen evolution reaction (OER) showed a proactive effect of both graphene materials toward catalysis. Moreover, the electrode prepared from the algae-based graphene showed the highest electrocatalytic activity. This fact could be explained by the different structure of the algae-based graphene which, due to differences in the nucleation growth patterns and electroactive sites developed during the electrodeposition process, produced more reactive NiFe species (higher oxidation state).

Cortaderia selloana (CS), is an invasive and exotic species that is generating significant invasive problems in the Iberian Peninsula ecosystems. The objective of this research was to study this plant potential thorough a pyrolytic process helping to reduce its expansion. Stems and leaves were subjected to conventional and flash pyrolysis. These processes were carried out in an original design oven using a 25 °C/min heating ramp at a 750 °C temperature and during 60 min at the pyrolysis temperature for conventional pyrolysis and with 750 °C and 850 °C pyrolysis temperatures for flash. Gas-fraction obtained by flash pyrolysis had higher HHV data when compared with conventional ones (∼17 MJ/kg vs ∼5 MJ/kg) due to their less CO2 and higher CO, CH4 and H2. The greater bio-oil yield was obtained for CSS-P (33.58%). The composition of conventional pyrolysis bio-oils had an overbearing of nonaromatic and monoaromatic hydrocarbons nature whereas bio-oils from flash pyrolysis were composed mainly of polycyclic aromatic hydrocarbons. Bio-char fraction was higher in CSL than CSS with HHV similar to lignite and bituminous coals (22.74–29.12 MJ/kg). After done the quantification and characterization of the fractions, it was concluded that a possible energetic valorization of Cortaderia selloana biomass was possible.

The use of phytoremediation to remove metals of contaminated soils is an interesting technique that is usually limited by adverse physical and chemical properties of this type of soils. The addition of biochar produced from manure waste could improve soil properties due to its nutrient content, high cation exchange capacity or water holding capacity. However, the high water content of manure wastes precludes its pyrolysis treatment use for biochar production, without a previous drying step. Indeed, hydrothermal carbonization (HTC) of manure wastes could be an adequate treatment method as it takes place in water solution. The product obtained after HTC of biomass, named hydrochar, exhibits different physiochemical properties than biochar that could affect their potential application. The objective of the present work is to study the effect of chars obtained by pyrolysis or HTC of manure wastes in mining soil phytoremediation with Sinapis alba. Two selected mining soils (PORT and GAM) were treated with two manure biochars prepared at 450 °C (BMW450) and 600 °C (BMW600), two hydrochars prepared by HTC of manure at 190 °C (HWM190) and 240 °C (HMW240) and raw manure waste (MW) at a rate of 10% in mass. Later, different soil samples were incubated with or without Sinapis alba growth. Experimental results shown that properties of chars have a great influence on the efficiency of the use of Sinapis alba in the phytoremediation of mining soils. The addition of BMW600 and raw material (MW) increased the production of aerial and root biomass for GAM soil. For PORT soil, HMW190, two biochars and MW increases root and aerial biomass whereas HMW240 only produces an increment on aerial biomass. Addition of two hydrochars and MW had a positive effect on the biochemical soil activities and the highest microbial biomass carbon of GAM and PORT soil samples was observed after addition of HMW190. Finally, the addition of biochars and hydrochars could improve the phytoremediation of mini

The increase of emerging pollutants (pesticides, pharmaceuticals, iodinated contrast media (ICM), ...) in surface and groundwater is a threat to the environment and to human health due to its toxicity and its persistence in water. In this work, the removal of pharmaceuticals and ICM by adsorption onto carbon xerogels and commercial activated carbons with different physicochemical properties is studied. Carbon xerogels have similar micropore volume and BET surface area (0.152 ± 5 cm3 g-1 and 625 ± 25 m2 g-1, respectively), with macropore and mesopore volume up to 0.63 cm3 g-1 and 1.09 cm3 g-1 and an average pore diameter from 8.8 to 45.6 nm. YAO activated carbon present the highest micropore volume and BET surface area (0.357 cm3 g-1 and 1092 m2 g-1, respectively). Small pores favor the pharmaceuticals adsorption and larger pores the uptake of ICM. The presence of polymeric groups in the carbon xerogels and ashes in the HYDC and YAO activated carbons (26.27% and 4.87%, respectively) provides a basic surface for enhancing the adsorption of acidic compounds. All adsorbents have a basic pH (9.3-11.6). The hydrophobicity or hydrophilicity of the adsorbates influences in different ways the adsorption process on porous carbon materials. Natural Organic Matter (NOM) influences in the retention of the pollutants by the carbon materials. There is a competition between the NOM and ICM for the large pores of the carbon xerogels (overall, r > 0.98 amount ICM adsorbed vs. Hg volume intrusion in mesopores). Electrostatic interactions between the natural organic matter and the salicylic and diatrizoic acids have the effect of reducing the quantity adsorbed.

This work draws on the concept of circular economy (CE) to advance knowledge toward the obtention of low-cost and sustainable activated carbons from a biocollagenic waste from the leather industry, and using them in biogas upgrading for energy recovery. The research pursues a series of benefits across different industrial applications. The first is the production of sustainable carbon-based absorbents: using a CE approach, our experiments re-valorize solid wastes generated in the vegetable tanning from leather industry to obtain activated carbons for environmental applications. The second benefit is related to biogas energy recovery, which plays a key role in achieving the targets of the European Renewable Directive, since biogas is a renewable fuel which presents additional environmental value reducing the release of greenhouse gases in the atmosphere. Sustainable activated carbons were obtained from biocollagenic industrial waste by chemical activation (KOH, NaOH, K2CO3), with and without a previous pyrolysis step, at different activation temperature (750 °C and 900 °C) and different activating agent/precursor weight ratio. The microporous adsorbent materials obtained showed good chemical and textural properties, with BET specific surface area and total pore volume of up to 1600 m2 g−1 and 0.76 cm3 g−1, respectively. These efficient and low cost activated carbons showed a siloxane adsorption capacity of up to 500 mg g−1, higher than that of the commercial steam activated carbons supplied by adsorbent producers that reached values of up to 349 mg g−1. The industrial biocollagenic waste if vegetal tanning successfully performed as precursor for sustainable low-cost activated carbons, and the materials obtained were proved to be efficient for gaseous pollutants abatement applications. Thus, this work resulted in an efficient valorization method that assists the reduction of coal extraction by obtaining eco-friendly activated carbons that can be beneficially used for

An unpublished low-cost industrial biomass waste, pomegranate peel, as alternative and sustainable fuel source was studied. A horizontal tubular furnace of original design for conventional and flash pyrolysis was carried out. The bio-char yields from both processes were similar, but the bio-oil and bio-gas yields were higher in flash pyrolysis, depending on the temperature. The bio-char obtained show that it could be used as a fuel (higher heating values ≥ 28.0 MJ/kg) and as a potential precursor of activated carbon. It was also found that the lower temperature of the flash pyrolysis was, the greater the bio-oil yield (∼53%) and that the higher was, the greater the biogas yield (∼50%). The bio-oil from conventional pyrolysis has a predominantly furanic nature and contained significant amounts of the phenols and benzenes. In contrast, the bio-oil from flash pyrolysis is similar to that of “anthracene oil”, both of them being composed mainly of polycyclic aromatic hydrocarbons. The bio-gas obtained by flash pyrolysis is of a higher quality than that obtained by conventional pyrolysis because it has a lower CO2 content (32.4% vs 66.6%) and higher syngas content (CO + H2) (50.8% vs 26.8%). Flash pyrolysis is better in CH4 production (11.6% vs 4.6%).

© 2021. 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 increase of emerging pollutants (pesticides, pharmaceuticals, iodinated contrast media (ICM), …) in surface and groundwater is a threat to the environment and to human health due to its toxicity and its persistence in water. In this work, the removal of pharmaceuticals and ICM by adsorption onto carbon xerogels and commercial activated carbons with different physicochemical properties is studied. Carbon xerogels have similar micropore volume and BET surface area (0.152 ± 5 cm3 g-1 and 625 ± 25 m2 g-1, respectively), with macropore and mesopore volume up to 0.63 cm3 g-1 and 1.09 cm3 g-1 and an average pore diameter from 8.8 to 45.6 nm. YAO activated carbon present the highest micropore volume and BET surface area (0.357 cm3 g-1 and 1092 m2 g-1, respectively). Small pores favor the pharmaceuticals adsorption and larger pores the uptake of ICM. The presence of polymeric groups in the carbon xerogels and ashes in the HYDC and YAO activated carbons (26.27% and 4.87%, respectively) provides a basic surface for enhancing the adsorption of acidic compounds. All adsorbents have a basic pH (9.3–11.6). The hydrophobicity or hydrophilicity of the adsorbates influences in different ways the adsorption process on porous carbon materials. Natural Organic Matter (NOM) influences in the retention of the pollutants by the carbon materials. There is a competition between the NOM and ICM for the large pores of the carbon xerogels (overall, r > 0.98 amount ICM adsorbed vs. Hg volume intrusion in mesopores). Electrostatic interactions between the natural organic matter and the salicylic and diatrizoic acids have the effect of reducing the quantity adsorbed., Peer Reviewed, Postprint (author's final draft)

The control of chemical, morphological, textural and magnetic properties developed in magnetic activated carbons (MACs) from industrial food waste, was achieved. The process parameters involved in a sustainable and optimized one-step activation route, based on the circular economy model, played an important role and its influence was studied, offering interesting and outstanding results. Magnetite crystals were formed on the MACs surface obtained from 400 °C to 800 °C while other iron species, such as metallic iron and iron carbides, were formed only at 800° C. Acid washing favored the mineral matter removal and the presence of iron species was drastically reduced in acid-washed MACs, mainly the iron species originated at 800 °C. Water-washed MACs presented better magnetic response at high temperatures (confirmed by XRD, FTIR, Raman, Mössbauer spectroscopy and VSM characterization techniques). High BET surface area (≈ 822 m/g) and a large micropore volume (≈ 0.30 cm/g), were reached by acid washed MACs at 800 °C. The obtained MACs were fundamentally microporous, but some mesoporosity was also observed when activating agent/precursor mass ratio (1:1) is used. It can be concluded that a MACs strategic design was reached with the objective of removing specific pollutants in multiple environmental applications.

Macroalgae wastes from the Agar–Agar industry were used as a feedstock to obtain hydrochars by means of hydrothermal carbonization. The effect of temperature (200 °C and 230 °C) and time (2 h and 6 h) on the yield, higher heating value (HHV) and chemical-morphological-textural properties of the hydrochars was studied. The carbon content and the higher heating value were observed to increase with the hydrothermal carbonization. The hydrochars yields (up to 60%) were much higher than yields obtained using conventional char (27.5–33.5%). The hydrochar obtained at 230 °C and after 6 h showed a HHV of 23.25 MJ/kg, which is similar to that of lignite HHV. The H/C and O/C atomic ratios decreased as a consequence of the dehydration and decarboxilation reactions. Hydrothermal carbonization barely changed the vegetal structure of the macroalgae waste. The hydrochars were found to be essentially meso-macroporous with average pore sizes of up to 110.5 nm.

The present paper evaluates the efficiency of sustainable activated carbons obtained from the valorization of lignocellulosic waste in removing siloxanes and volatile organic compounds for the purification of anaerobic digester biogas. Pyrolized and non-pyrolized lignocellulosic residues generated in food and wood industries were used as precursor materials to obtain experimental adsorbents by a chemical activation process using several activating agents. The highest porosity was obtained by non-pyrolized residue activated by K2CO3 at 900 °C. The performance of the experimental materials was compared with that of commercial activated carbons in gas adsorption tests of siloxanes (octamethylcyclotetrasiloxane and hexamethyldisiloxane) and volatile organic compounds (toluene and limonene). The waste-based activated carbons developed in this work proved to be more efficient for the removal of both siloxanes and VOCs than the commercial samples in most of the conditions tested. Adsorption capacities correlated with porosity, while the more relevant pore size depends on the adsorbate.

A novel thermochemical process based on a single step was optimized to obtain magnetic activated carbons from an industrial biomass waste. Anhydrous iron chloride was used as an activating agent and mixed directly with the chestnut shell waste. The effect of the activation temperature (220-800 °C) on the chemical, morphological, textural, and magnetic properties of the materials was studied. The results demonstrated the presence of different iron compounds depending on the activation temperature set as well as their influence on morphological and textural development of the magnetic activated carbons (BET specific surface area, S up to 568 m g, total pore volume, V, up to 0.294 cm g vs 1 m g and 0.007 cm g, respectively, for the raw biomass waste). The techniques employed, especially Mössbauer spectroscopy, showed relative contributions of the different iron compounds (magnetite, maghemite, metallic iron, and so on) in the materials. The higher activation temperature (800 °C) favored the formation of metal Fe and iron carbide. Additionally, the magnetic properties measured by vibrating sample magnetometry confirmed the coexistence of different ferromagnetic phases with the remanent magnetization, M, (up to 3.88 emu/g) and coercivity, H, (up to 140 Oe), being larger as the activation temperature increases. A higher activation temperature favored the development and evolution toward other iron compounds, while at low temperature, 220 °C, the presence of these compounds were null, and their behavior resembled the results obtained for the original biomass waste.

Peer Reviewed, Postprint (author's final draft)

Peer Reviewed, Postprint (author's final draft)

[EN] The present memory is aimed at a comprehensive use of macroalgae waste, Algae meal, from the Agar-Agar industry as a source of energy for the pyrolysis process and as to preparare of activated carbons from algae meal and its carbonized products. The work was provided by the operating programme FEDER of the Principado de Asturias 2007–2013. The Algae meal was pyrolysed using two different heating methods: pyrolysis in an electrical furnace and pyrolysis in a microwave furnace. In both cases three fractions were obtained for use in industrial applications: 1) a solid fraction , char, which can be used as precursor of activated carbons or as a fuel, having the best chemical properties the one that is obtained by conventional pyrolysis; 2) a liquid fraction , bio- oils, which can be applied as fuel after a pretreatment for the removal of nitrogen compounds; and 3) a gaseous fraction , biogas , which can also be used as fuel or as a raw material in chemical synthesis due to its high syngas content, especially in the case of microwave pyrolysis. As regards to the preparation of activated carbons, the chemical activation conditions were optimized, to obtain adsorbents that can be applied for the retention of gaseous pollutant. Two types of precursors were used, Algae meal and its char obtained by pyrolysis, using two different heating methods : conventional activation and microwave activation. In addition, the influence of the activation temperature and the activating agent/precursor ratio were studied. In general, the activated carbons obtained had very good chemical and textural properties: they were mainly microporous and had specific surface areas of up to 2118 m2/g. The best adsorbent materials were those obtained by conventional activation, using Algae meal as precursor, at temperatures between 750-900 °C and activation agent/precursor ratios of 0.5:1 and 1:1. Once prepared and characterized, some of the activated carbons were used to capture CO2, CH4 and H2 at, [ES] La presente memoria tiene como objetivo el aprovechamiento integral de un residuo de macroalga, Harina de Algas, procedente de la industria del Agar- Agar, mediante dos vías bien diferenciadas: por un lado la valorización energética de este residuo mediante un proceso de pirólisis y por otro lado la preparación de carbones activados a partir de la Harina de algas y de su carbonizado obtenido en dicho proceso de pirólisis. Todo ello se encuentra financiado dentro del programa operativo FEDER del Principado de Asturias (2007-2013). En lo referente a la pirólisis de la Harina de algas, se han abordado dos metodologías de calentamiento diferentes: la pirólisis en horno eléctrico convencional y la pirólisis en horno microondas. En ambos casos se han obtenido tres fracciones que pueden tener una aplicación industrial: 1) una sólida, carbonizado o char, que puede ser utilizada como precursor de carbones activados o como combustible, teniendo mejores propiedades químicas la fracción obtenida mediante pirolisis convencional; 2) una líquida, conocida como bio-aceites, que podría ser aplicada como combustible si se realiza un pre-tratamiento de eliminación de compuestos nitrogenados y 3) una fracción gaseosa, bio-gas, que podría también ser usada como combustible o en la síntesis de productos químicos dado su alto contenido en gas de síntesis, sobre todo en el caso del bio-gas obtenido mediante pirólisis en microondas. Con respecto a la preparación de carbones activados se han optimizado las condiciones de activación química para la obtención de materiales adsorbentes que pudieran ser aplicados a la retención de contaminantes gaseosos. Se han utilizado dos tipos de precursores, Harina de algas y su carbonizado, y dos metodologías de calentamiento diferentes: activación convencional y activación microondas. Además, se ha estudiado la influencia de la temperatura de activación y la relación de agente activante/precursor. En general, se obtuvieron carbones activados con muy

[EN] Tanning Industry comprises a series of productive activities aimed at the recovery and handling of skins wastes of slaughtered animals for human consumption, to provide adequate raw material for footwear, clothing, leather goods and upholstery industries. Despite using a waste of the meat industry, we can not forget that the tanning industry has some impact from the environmental point of view. The final aim of this thesis is to obtain a methodology for the valorization of tanning solid waste into activated carbons with environmental applications on gaseous emissions, studying the energy use of the fractions generated during the pyrolysis of the precursor. This thesis is part of a PETRI project: “Aprovechamiento integral de residuos sólidos de empresas de curtición: obtención de carbón activado mediante procesos termoquímicos con aprovechamiento energético en etapas del proceso” (PET2007_0421_02), 2007- 2009, with the finnatial support of MEC and participation of: University of Girona, the technological center AIICA (Research Association for the Leather Industries and Anexes) and the company Miquel Farrés Rojas SA, the last two entities being part in the Tanning Sector. Initially, we carried out the characterization of different untanned skins and leathers tanned by various tanning agents (chromium salts and vegetable tannins), in order to study the influence of tanning process in the porosity of these materials and in the ability of water vapor adsorption. From the water vapour adsorption data obtained from the leather and untanned skin in various stages of relative humidity, it can obtain knowledge about the nature of the surfaces, thus to improve the tanning process by performing the relevant settings or to know the moisture needed for good comfort of a garment. The characterization of the different fractions (pyrolyzed material or char, condensable liquid and gas) obtained from the pyrolysis of the leather solid wastes, was carried out. The calorific value

The aim of this study is to understand the different sorption behaviors of mercury species on activated carbons in the oxy-fuel combustion of coal and the effect of high quantities of water vapor on the retention process. The work evaluates the interactions between the mercury species and a series of activated carbons prepared from a macroalgae waste (algae meal) from the agar–agar industry in oxy-combustion atmospheres, focussing on the role that the high concentration of water in the flue gases plays in mercury retention. Two novel aspects are considered in this work (i) the impact of oxy-combustion gases on the retention of mercury by activated carbons and (ii) the performance of activated carbons prepared from biomass algae wastes for this application. The results obtained at laboratory scale indicate that the effect of the chemical and textural characteristics of the activated carbons on mercury capture is not as important as that of reactive gases, such as the SOx and water vapor present in the flue gas. Mercury retention was found to be much lower in the oxy-combustion atmosphere than in the O2 + N2 (12.6% O2) atmosphere. However, the oxidation of elemental mercury (Hg0) to form oxidized mercury (Hg2+) amounted to 60%, resulting in an enhancement of mercury retention in the flue gas desulfurization units and a reduction in the amalgamation of Hg0 in the CO2 compression unit. This result is of considerable importance for the development of technologies based on activated carbon sorbents for mercury control in oxy-combustion processes.

This study evaluates the capacity of a series of activated carbons obtained from leather industry waste to retain mercury. The behavior of these materials was compared in two simulated flue gas compositions at laboratory scale. The atmospheres were (i) a typical coal oxy-fuel combustion atmosphere and (ii) an O2 + N2 atmosphere. The activated carbons displayed different behaviors depending on their characteristics and the gas composition. The best results were obtained for the activated carbon with the highest surface area and greatest amount of micropores, sulfur and acidity character, these results being comparable to those of an activated carbon impregnated with sulfur specifically designed for capturing elemental mercury. The highest level of mercury retention was achieved in a O2 + N2 atmosphere. However, independently of the ability of these materials to capture mercury, their most interesting characteristic was their ability to oxidize mercury in an oxy-combustion atmosphere, since this would facilitate the retention of mercury in flue gas desulfurization units with the consequence that the risk of damage to the CO2 compression and purification units would be reduced or even removed.

[EN] A comparative study of the pyrolysis of a macroalgae industrial solid waste (algae meal) in an electrical conventional furnace and in a microwave furnace has been carried out. It was found that the chars obtained from both pyrolyses are similar and show good properties for performing as a solid bio-fuel and as a precursor of activated carbon. Bio-oils from conventional pyrolysis have a greater number of phenolic, pyrrole and alkane compounds whereas benzene and pyridine compounds are more predominant in microwave pyrolysis with a major presence of light compounds. The bio-gas fraction from microwave pyrolysis presents a much higher syngas content (H2 + CO), and a lower CO2 and CH4 proportion than that obtained by conventional pyrolysis. Yields are similar for both treatments with a slightly higher gas yield in the case of microwave pyrolysis due to the fact that microwave heating favors heterogeneous reactions between the gases and the char.

La presente invención está dirigida a un nuevo carbón activado que se caracteriza por su alto contenido en nitrógeno, así como al método de obtención del mismo a partir de residuos sólidos industriales de curtido vegetal de piel bovina, o de piel bovina sin curtir libre de taninos, desgrasada y deshidratada con acetona, comprendiendo el método las siguientes etapas: triturar el material de partida después de secarlo en el caso de que sea necesario para obtener un precursor, someter el precursor a tratamiento termoquímico de activación con hidróxido de potasio, lavar el material con ácido clorhídrico y agua destilada, y secar el carbón activado. Asimismo, la presente invención trata del uso del carbón activado en procesos de retención de gases, como es la captura de CO2 o la purificación de mezclas CO2/H2.

[EN] The present invention relates to a novel activated charcoal which is characterised by having high nitrogen content, and to the method for obtaining same from solid industrial waste from vegetable tanning of bovine hides, or from tannin-free non-tanned bovine hide, which has been defatted and dehydrated with acetone, said method including the following steps: grinding up the starting material after drying same if necessary in order to obtain a precursor, subjecting the precursor to thermochemical activation treatment with potassium hydroxide, washing the material with hydrochloric acid and distilled water, and drying the activated charcoal. Likewise, the present invention relates to the use of activated charcoal in gas-retention processes, such as the capture of CO2 or the purification of CO2/H2 mixes., [ES] La presente invención está dirigida a un nuevo carbón activado que se caracteriza por su alto contenido en nitrógeno, así como al método de obtención del mismo a partir de residuos sólidos industriales de curtido vegetal de piel bovina, o de piel bovina sin curtir libre de taninos, desgrasada y deshidratada con acetona, comprendiendo el método las siguientes etapas: triturar el material de partida después de secarlo en el caso de que sea necesario para obtener un precursor, someter el precursor a tratamiento termoquímico de activación con hidróxido de potasio, lavar el material con ácido clorhídrico y agua destilada, y secar el carbón activado. Asimismo, la presente invención trata del uso del carbón activado en procesos de retención de gases, como es la captura de CO2 o la purificación de mezclas CO2/H2

The use of activated carbons (ACs) for environmental applications is widening as new challenges emerge. In recent years, for example, particular attention has been focused on ammonia abatement at room temperature. This particular interest is closely related to odour control issues. NH3 is frequently present in odorous emissions from a variety of industries, such as wastewater treatment plants.

Grinding of a high volatile bituminous coal was performed in three comminution devices: Raymond Mill (RM), Rolls Crusher (RC) and Ball Mill (BM). The pulverised samples were sieved to obtain four particle size fractions, and temperature-programmed combustion (TPC) was used for the evaluation of their combustion behaviour. In addition, three coals of different hardness and rank were mixed in various proportions in order to compare the combustibility characteristics of the binary coal blends with those of the individual coals. The effect of coal blending on grindability was also studied. It was found that grindability was non-additive especially when coals of very different Hardgrove Grindability Index (HGI) were blended. The combustion studies also suggested that there exists an interaction between individual coals when they are burnt as a blend.

Differences between primary quinoline insoluble (QI) material of coal tars and their derived pitches caused by preheating carbonization have been studied using microscopic techniques, Coulter Laser particle size analysis and solid-state C-13 NMR. The selected tars were produced from the same coal using wet and preheated charging at the INCAR experimental coking test plant, which operates on a semi-industrial scale. Specific operational conditions were successfully applied not only to reduce the ash content and the QI and toluene insoluble (TI) contents in the tars produced by the preheating process, but also to modify the nature of the QI particles. In addition, structural changes in the insoluble materials formed during the pitch production from the tar have been monitored.