Design of activated carbon–clay composites for effluent decontamination

Adsorption offers an efficient technology for removing volatile organic compounds (VOCs) from air pollution sources. Often activated carbons (ACs) are employed owing to their large specific surface areas, high micropore volumes, rapid adsorption capabilities and selectivity towards organic molecules compared to water vapour or air. However, when large volumes of gas are to be treated pressure drop limitations may arise from the use of conventional powder adsorption beds. For these applications conformation of the activated carbon as open channel honeycomb monoliths can take advantage of the almost null pressure drop caused by these structures. Similarly, conformation as extrudates or tubes although increasing the pressure drop due to the turbulent gas flow can improve any diffusion limitations that the open channel monoliths can suffer. Conformation of the AC as a ceramic composite also improves the handling characteristics. By the use of a silicate clay binder a commercially available AC, was conformed in three different monolithic geometries; changing the channel width and the wall thicknesses and as solid extrudates and tubes. The textural and mechanical properties of these conformed composite structures were determined and the results analysed along with their dynamic adsorption capacities towards toluene at 30 C, used as a probe molecule to establish criteria by which the most suitable structure for industrial use could be selected.This work has been supported by the CICYT project MAT2009-09960, Community of Madrid project S-0505/MAT/000227 and CDTI IDI-20091139

Characterization and application of a sterol esterase immobilized on polyacrylate epoxy-activated carriers (DilbeadsTM)

The sterol esterase from the ascomycete Ophiostoma piceae was immobilized on novel polyacrylate-based epoxy-activated carriers (DilbeadsTM). Six supports with particle sizes between 120-165 micrometers were prepared varying the composition of monomers, crosslinkers and porogens. Their surface areas and porosities were determined by N2 adsorption and mercury intrusion porosimetry. The pore volumes ranged from 0.63 to 1.32 cm3/g, but only DilbeadsTM RS and NK had narrow pore size distributions (with maxima at 33.5 and 67.0 nm, respectively). The distribution of the enzyme in the support was studied by fluorescence confocal microscopy. The immobilized esterase on DilbeadsTM TA showed a significant pH and thermal stability and was assayed in the continuous hydrolysis of cholesteryl esters -present in the pulp industry process waters-.We thank Mª Teresa Seisdedos (Centro de Investigaciones Biologicas, CSIC) for help with the confocal microscopy. This research was supported by the Spanish Ministry of Education and Science (Projects BIO2002-00337 and BIO2003-00621) and Comunidad de Madrid (Project S-0505/AMB0100). We thank CSIC for a research fellowshipPeer reviewe

Preparación de materiales biocompatibles a partir de desechos del proceso de fabricación de cerveza y sus usos

La presente invención se refiere a un procedimiento 5 de obtención de material biocompatible a partir del secado y tratamiento térmico de bagazo de cerveza, así como su uso en ingeniería de tejidos óseosPeer reviewe

Absorbentes reactivos y su uso para la desulfuración de corrientes gaseosas

Absorbentes reactivos y su uso para la desulfuración de corrientes gaseosas. La presente invención se refiere a un material poroso que comprende un soporte de arcilla modificada mediante un agente generador de poros y al menos un óxido de un metal que se selecciona entre la primera serie de transición. Además se refiere a un procedimiento de obtención de este material y al uso de dicho material para la desulfuración de corrientes gaseosas, especialmente para la eliminación de H2S.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patentes con informe sobre el estado de la técnic

Zeolitic materials as catalysts for organic syntheses

The major applications of zeolitic materials are as cation exchangers, selective adsorbents, catalysts and catalyst supports (mainly in catalytic cracking, hydroisomerization and aromatics processing). Their use in the synthesis of hydrocarbon intermediates and fine chemicals is at an earlier stage of research, although several international reunions and reviews have already shown the improvement achieved by using these solids in conventional catalytic processes. This improvement is found mainly in activity, selectivity and environmental concerns, new more environmentally friendly routes having been found for processes which previously produced undesirable side reactions or high amounts of environmentally hazardous residues (with the subsequent economic considerations). More than a hundred references form the main body of the present piece of work, which has three major objectives, the first of which is to outline the main properties of zeolitic materials in relation to their use as catalysts in organic syntheses, the second to present an up to date bibliographic review of their use for such purposes and the third to show the main improvements that these materials present with respect to the more conventional catalysts

The dynamic adsorption behaviour of volatile organic compounds VOCs on activated carbon honeycomb monoliths

Conference paper presented at the 6th International Symposium on the Characterization of Porous Solids (COPS-VI), 8-11th May 2002, Alicante (Spain).Adsorption offers an efficient technology for removing volatile organic compounds (VOCs) from air pollution sources. Often activated carbons (ACs) are employed owing to their large specific surface areas, high micropore volumes, rapid adsorption capabilities and selectivity towards organic molecules compared to water vapour or air. However, when large volumes of gas have to be treated pressure drop limitations may arise from the use of conventional adsorption beds. For these applications conformation of the adsorption bed as honeycomb monoliths take advantage of the negligible pressure drop of these structures. Commercially available ACs were conformed as honeycomb monoliths with a magnesium silicate clay as binder. The textural and mechanical properties of the raw materials and the monolith composites were determined. These results were analysed together with the dynamic adsorption capacities towards o-dichlorobenzene (o-DCB) a chlorinated probe molecule used to simulate a dioxin. With this data, criteria by which the dynamic adsorption capacity could be related to the textural properties of the adsorption units were established

Sustainable Materials and Biorefinery Chemicals from Agriwastes

Agriculture is one of the pillars of society, especially given the increasing world population. Countries which have large agricultural resources, such as Spain, also produce vast amounts of residues and wastes, that can be an environmental hazard, difficult to store, easily generating leakages and greenhouse gases such as ammonia, methane and carbon, nitrogen and sulphur oxides when burnt, therefore negatively impacting on the environment. However, these agriwastes can also be considered as a source of low cost renewable raw materials (RRM) that with the proper treatment can have applications in a wide range of processes, i.e. energy production, materials (fertilizers, animal feed, biodegradable plastics, resins, textiles, fibres, paper, etc.) and chemicals (platform molecules, solvents, additives), inside the Biorefinery concept, with the added bonus of not competing with food resources [4].Peer reviewe

Preparación de materiales biocompatibles a partir de desechos del proceso de fabricación de cerveza y sus usos

Filing Date: (2009-10-29).-- Priority Data: ES P200803331 (2008-11-21).-- Titular: Consejo Superior de Investigaciones Científicas (CSIC).[EN] The present invention refers to the process of obtainment of biocompatible material comprising phosphates and silicates from waste from the agri-food industry, more specifically from drying and heat treatment of wet brewer's grains, a residue from the manufacture of beer. The invention furthermore relates to the use of these biocompatible materials in osseous tissue engineering.[ES] La presente invención se refiere al procedimiento de obtención de material biocompatible que comprenden fosfatos y silicatos, a partir de desechos de la industria agroalimentaria, y más concretamente a partir del secado y tratamiento térmico de bagazo de cerveza, residuo precedente de la fabricación de cerveza. La invención también se refiere al uso de estos materiales biocompatibles en ingeniería de tejidos óseos.Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patente con informe sobre el estado de la técnic

Study of the efficiency of monolithic activated carbon adsorption units

Conference paper presented at the 7th International Symposium on the Characterization of Porous Solids (COPS-VII), Aix-en-Provence, France, 26-28th May 2005.Although the use of activated carbons as a purification step in the treatment of gaseous effluents from industrial plants is a well established technique, when large volumes of gas need to be treated pressure drop limitations may arise from the use of conventional adsorption beds. For these applications the conformation of the adsorption bed as honeycomb monoliths with high activated carbon content take advantage of the almost null pressure drop of these open channel structures and significantly improves the handling characteristics. In this study a commercial activated carbon was conformed as a ceramic monolith using a natural magnesium silicate as the agglomerating agent. The adsorption studies employed orthodichlorobenzene (o-DCB) as a probe molecule, since it can be considered as representing approximately half a molecule of tetra-chloro-dibenzene-dioxin (TCDD) the most toxic isomer of the dioxin family. It has been shown that the dynamic adsorption capacity of these units at 30°C was equivalent to the micropore volume. However, in industrial applications the adsorption step should take place at higher temperatures so that the gases exiting from the chimney rise rapidly into the upper atmosphere. Thus, the adsorption capacities of these units were determined over a range of temperatures from 30°C to 150°C at linear gas velocities between 0.3m·s-1 to 2m·s-1. The effects of variation in the monolith geometry: overall length versus gas linear velocity, on the dynamic adsorption capacity were studied in order to predict the optimum monolith dimensions depending on the gas flow to be treated

Synthesis and characterisation of hydrotalcites produced by an aluminium hazardous waste: A comparison between the use of ammonia and the use of triethanolamine

Hydrotalcite-like compounds were co-precipitated with diluted sodium hydroxide from an unconventional aluminium source: the aluminium waste generated by the tertiary aluminium industry, with the assistance of ammonia and triethanolamine at pH 10. These products were characterised by several techniques (XRD, FT-IR, UV¿vis-NIR, SEM, DTA-TG and BET methods) to compare results. The characterisation of products confirmed significant differences depending on basic reagent selected. Products co-precipitated with ammonia showed less crystal growth, a more significant iron content in the structure and higher internal surface area. Products from triethanolamine showed the entry of organicmolecules into the layered structure. These findingswere important for the improvement of methods based on waste treatment, transforming an aluminium hazardous waste into a value added product as layered double hydroxides.The authors would like to thank the company Metalquex, S.L. (Zaragoza, Spain) for supplying wastes, and CSIC for the financial support (P.I.E. 201260E115). They also gratefully acknowledge the assistance provided by Dr. Blanca Casal for helpful discussion during this research, and especially to Professor Guillermo Monrós (UJI) for allowing us to record the UV–vis-NIR spectra.Peer Reviewe