Depuración de emisiones ácidas en un horno de ladrillos que usa coque de petróleo como combustible

En el trabajo que se presenta se ha estudiado un sistema de depuración de emisiones gaseosas de compuestos ácidos basado en el uso de hidróxido cálcico como reactante y filtros de mangas como sistema separador gas-sólido. Concretamente, el sistema se ha instalado en la empresa Herederos de Márquez Villar, S. L., dedicada a la fabricación de ladrillos cerámicos. El horno estudiado utiliza como combustible gas natural (precalentamiento) y coque de petróleo micronizado (en las zonas de mayor temperatura). Operando en esas condiciones, aparte del material articulado, el contaminante más crítico para cumplir los requisitos medioambientales impuestos a la empresa en su Autorización Ambiental Integrada son los óxidos de azufre (SOx). La aplicación de estos sistemas de depuración basados en el uso de hidróxido de calcio y filtros de mangas es muy común para la depuración de compuestos ácidos (HF, HCl y SOx). En el caso de los compuestos de flúor, suelen presentar elevados rendimientos (>90%), pero según la bibliografía [1] presenta un rendimiento menor y muy variable en la depuración de compuestos de azufre (7-80%), por lo que el diseño del sistema debe realizarse de forma más detallada para obtener rendimientos adecuados que permitan cumplir las especificaciones impuestas por la normativa medioambiental. El trabajo que se presenta es fruto de la colaboración de la empresa Márquez, en cuyas instalaciones de Bailén se ha realizado el estudio; de la empresa Talleres Movigi, S.L., que ha desarrollado las actividades de diseño y construcción del sistema de depuración, y del Instituto de Tecnología Cerámica, que ha realizado la caracterización de las emisiones gaseosas y del material residual recogido en los filtros de mangas,y también ha participado en el diseño y definición de los parámetros de operación del sistema de filtración estudiadoThis work studies a system of purification of gaseous emissions of acid compounds based on the use of calcium hydroxide as a reactant and bag filters as a gas-solid separator system. Specifically, the system has been installed in the company Herederos de Márquez Villar, S.L., dedicated to the manufacture of ceramic bricks. The kiln studied uses natural gas as a fuel (preheating) and micronized petroleum coke (in the areas of highest temperature). When operating in these conditions, apart from the particulate material, the most critical pollutant to meet the environmental requirements imposed on the company in its Integrated Environmental Authorization are sulphur oxides (SOx). The application of these purification systems based on the use of calcium hydroxide and bag filters is very common for the purification of acid compounds (HF, HCl and SOx). In the case of fluorine compounds, they typically have high outputs (> 90%) but, according to literature [1], they present a lower and highly variable output in the purification of sulphur compounds (7-80%). For this reason, the design of the system must be performed on a more detailed way to achieve more appropriate outputs that comply with the specifications imposed by environmental regulations. The work presented is a collaboration of the company above mentioned, in whose facilities in Bailén the study has been carried out; the company Talleres Movigi, S.L., which has developed the activities of design and construction of the purification system, and the Institute of Ceramic Technology, which has developed the characterization of gaseous emissions and the residual material collected in the bag filters, and has also participated in the design and definition of the operating parameters of the filtration system studie

Strategic environmental communication tools

Ponència presentada a QUALICER'14, XIII Congreso Mundial de la Calidad del Azulejo y del Pavimento Cerámico, celebrat a Castelló, 17-18 febrer 2014The Instituto de Tecnología Cerámica (ITC), pursuing its programme of actions aimed at transferring knowledge to the ceramic industry, presents the following work to facilitate the entry of ceramic coverings to markets demanding sustainable or green products and to national and international sustainable building certification programmes. At present, for the industry in general and for the ceramic industry in particular, companies seeking to respond to green market demands face serious difficulties owing to the vast number of existing certificates, ecolabellings, and eco-features, which adversely affect the decision-taking process in this sense. In this context, ITC has focused on developing, adapting, and fine-tuning a series of the most demanded eco-features, currently deemed the most complete for ceramic coverings

Emisión de compuestos de flúor durante la cocción de baldosas cerámicas

El trabajo profundiza en el conocimiento científico relativo a la emisión de contaminantes ácidos de naturaleza gaseosa que tiene lugar durante el tratamiento térmico de baldosas cerámicas. Se ha prestado especial atención a los compuestos de flúor por sus implicaciones ambientales y porque son considerados como los contaminantes característicos de la industria cerámica. Una parte muy importante del trabajo desarrollado se ha llevado a cabo a nivel industrial sobre hornos continuos de cocción rápida, monoestrato, y que utilizan como combustible gas natural.This study has focussed on the emission of acidic pollutants of a gaseous nature that takes place during the heat treatment of ceramic tiles. Attention has been paid to fluorine compounds because of their environmental implications and because they are considered as the characteristic pollutants of the ceramic industry. A very important part of the work has been carried out at the industrial level on continuous fast-cycle combustion kilns (roller kilns) fuelled by natural gas

Monitoring and possible reduction of HF in stack flue gases from ceramic tiles

HF (hydrogen fluoride) emission control is one of the critical environmental parameters in the firing of ceramic materials at peak temperatures higher than 1000 °C. In this study, in-stack concentrations of HF were monitored on-line with laser-based equipment during the fast firing of ceramic tiles in continuous industrial roller hearth kilns under standard kiln operating conditions. Three different ceramic tile compositions: porous red-body wall tiles, red-body stoneware tiles, and porcelain tiles were fired in industrial kilns customarily used to manufacture these types of tiles, modifying the heating rate and tile dry bulk density. The in-stack concentrations of HF can be explained on the basis of tile HF adsorption and emission processes in the kiln preheating and firing zones, analysed in previous studies. The methodology used in this study has significant advantages for industrial studies compared with previous methodologies based primarily on laboratory-scale studies and analysis of solid material. The main advantages are: (a) rapid response, allowing abrupt changes in the HF emission to be studied; and (b) direct measurement of the in-stack concentration of HF, which is the most common parameter used as a legal limit for industrial emission control. The study shows that tile HF adsorption in the preheating zone is very important. It also shows that HF stack emissions can vary significantly in continuous kilns depending on whether glazed or unglazed tiles are produced, or important changes occur in production (such as gaps in the kiln feed). The results indicate, furthermore, that HF stack emissions do not decrease significantly when realistic changes are made in industrial operating conditions if these industrial kilns are run at peak temperatures above 1100 °C. The most important reduction in in-stack concentrations of HF is observed when glazed ceramic tiles are fired, so further research in this field can be made in order to reduce HF emissions. © 2009 Elsevier B.V. All rights reserved

Evolution of fluorine emissions during the fast firing of ceramic tile

The present paper examines the emission-adsorption phenomena of fluorine compounds in various ceramic tile body compositions with different fluorine and calcium contents, processed by fast firing cycles in an electric laboratory batch kiln and in continuous fast-cycle industrial combustion kilns (roller kilns). In the roller kilns, fluorine emission was monitored by analysing the fluorine content in both solid and gas samples throughout the kilns. It was found that fluorine emission during firing in air atmosphere in the laboratory batch kiln began at temperatures above 800 °C and increased progressively up to peak firing temperature. In the roller kilns, however, the emissions started at lower temperatures and decreased in certain kiln zones. This decrease indicates that there are regions in these kilns in which fluorine is adsorbed rather than emitted by the material being processed. A fluorine adsorption process is thus shown to occur in the preheating stage in the roller kilns, despite the rapid heating rate. However, encouraging this adsorption process in order to foster the formation of crystalline phases is ineffective in abating fluorine emissions when ceramic tiles are fired at peak temperatures exceeding 1100 °C. © 2007 Elsevier B.V. All rights reserved

Diffuse PM10emission factors associated with dust abatement technologies in the ceramic industry

In this paper, an analytical methodology is proposed for estimating diffuse dust emissions from bulk solids managing (storage, handling, and transport) activities in the ceramic industry. The methodology is based on analytical methods drawn from the AP-42, US Environmental Protection Agency reports and the Emission Estimation Technique (EET) Manual for Mining from Environment Australia. The analytical methods were evaluated by means of experimental campaigns in open and closed bulk solids storage and managing facilities in ceramic plants. Dust concentrations and meteorological variables were recorded in experimental field studies in order to implement the experimental models: a method based on Reverse Dispersion Modelling (RDM) was applied in open facilities, and the Roof Monitor Method (RMM) was used to estimate diffuse dust emissions in closed facilities. The proposed methodology was applied to 13 ceramic plants with different technological scenarios. The methodology enabled the diffuse PM10 emission factors associated with different dust abatement technologies to be determined. This methodology thus allows the Best Available Techniques (BATs) to be selected for reducing these emissions in ceramic and similar facilities.This study was supported by the Spanish Ministry of Science and Innovation, through the National Plan for Scientific Research, Development, and Technological Innovation 2008–2011, by funding project CGL2009-14680-C02-0

Channeled PM10, PM2.5 and PM1 Emission Factors Associated with the Ceramic Process and Abatement Technologies

A sampling methodology and a mathematical data treatment were developed that enable to determine not only total suspended particulates (TSP) emitted at channeled sources but also the PM10, PM2.5, and PM1 mass fractions (w10, w2.5, and w1) and emission factors (E.F.), using a seven-stage cascade impactor. Moreover, a chemical analysis was performed to identify the elements present in these emissions. The proposed methodology was applied to different stages of the ceramic process, including ambient temperature (milling, shaping, glazing) and medium–high-temperature (spray-drying, drying, firing, and frit melting) stages. In total, more than 100 measurements were performed (pilot scale and industrial scale), which leads to a measurement time of 1500 h. Related to the mass fractions, in general, the mean values of w10 after the fabric filters operated at high performance are high and with little dispersion (75–85%), and it is also observed that they are practically independent of the stage considered, i.e., they are not significantly dependent on the initial PSD of the stream to be treated. In the case of the fine fraction w2.5, the behavior is more complex (w2.5: 30–60%), probably because the only variable is not the cleaning system, but also the nature of the processed material. Regarding abatement measures, the use of high-efficiency cleaning systems considerably reduces the emission factors obtained for fractions PM10, PM2.5, and PM1. In reference to chemical analysis, the presence of ZrO2 and Ni in the spray-drying and pressing stages, the significant concentration of ZrO2 in the glazing stage, the presence of Pb, As, and Zn in the firing stage, and the presence of Zn, Pb, Cd, and As compounds in the frits manufacturing should all be highlighted. Nevertheless, it should be pointed out that the use of some compounds, such as cadmium and lead, has been very limited in the last years and, therefore, presumably, the presence of these elements in the emissions should have been also reduced in the same way