Estimation of Industrial Emissions during Pyrolysis and Combustion of Different Wastes Using Laboratory Data

In our lab, we have been studying the emissions of different pollutants during pyrolysis and combustion of wastes under different conditions for the last three decades. These studies have focused on the effect of temperature and presence of oxygen on the production of different pollutants. Waste decomposition has been studied in a horizontal laboratory scale reactor, but no estimate has been made of the actual emissions in a conventional thermal decomposition system. In the present study, emissions during these wastes’ thermal decomposition were estimated using Aspen HYSYS. In the simulation software, the waste composition (elemental analysis) was given as an input parameter, as well as the gas flow rate used as atmosphere during the decomposition. The emitted hydrocarbons measured in the laboratory were equated to the emission of a single compound (propylene). The simulation permitted calculating the percentage of oxygen in the emitted gas, and the pollutant emissions were then recalculated under standard conditions. The emission of dioxins and furans were estimated under different conditions of decomposition, and an adequate approximation of the waste decomposition in actual incineration systems could be obtained.Support for this work was provided by the CTQ2016-76608-R project from the Ministry of Economy, Industry and Competitiveness (Spain) and the UAUSTI18-06 grant from University of Alicante (Spain). Damià Palmer thanks IQS – Universitat Ramon Llull for its financial support

New Models Used to Determine the Dioxins Total Amount and Toxicity (TEQ) in Atmospheric Emissions from Thermal Processes

In order to reduce the calculation effort during the simulation of the emission of polychlorinated dibenzo-p-dioxins and furans (PCDD/F) during municipal solid waste incineration, minimizing the number of simulated components is mandatory. For this purpose, two new multilinear regression models capable of determining the dioxins total amount and toxicity of an atmospheric emission have been adjusted based on previously published ones. The new source of data used (almost 200 PCDD/F analyses) provides a wider range of application to the models, increasing also the diversity of the emission sources, from industrial and laboratory scale thermal processes. Only three of the 17 toxic congeners (1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and OCDF), whose formation was found to be linearly independent, were necessary as inputs for the models. All model parameters have been statistically validated and their confidence intervals have been calculated using the Bootstrap method. The resulting coefficients of determination (R2) for the models are 0.9711 ± 0.0056 and 0.9583 ± 0.0085; its root mean square errors (RMSE) are 0.2115 and 0.2424, and its mean absolute errors (MAE) are 0.1541 and 0.1733 respectively.Juan A. Conesa and Nuria Ortuño acknowledge the support for this work by the CTQ2016-76608-R project from the Ministry of Economy, Industry and Competitiveness (Spain). Damià Palmer thanks IQS—Universitat Ramon Llull for its financial support

Prediction of the emission of dioxins and furans during processes of thermal degradation of waste

La producció de Residu Sòlid Urbà (RSU) no ha parat d’incrementar en els últims 20 anys a la major part de països de la UE. La seva gestió, adoptant la filosofia de l’Economia Circular que ha promogut la UE, és un dels reptes ambientals que la societat ha de resoldre en els propers anys. Des de la declaració de l’abocament de residus com a última opció de gestió i, en la mesura del possible, opció a evitar, l’ús d’incineradores de RSU amb recuperació d’energia ha anat agafant protagonisme com a mesura de gestió de residus. La formació de dibenzo-p-dioxines i dibenzofurans policlorats (PCDD/Fs) es considera com un dels problemes ambientals relacionats amb la incineració de RSU. Aquesta família de molècules, que han estat identificades com extremadament tòxiques, són complexes d’analitzar en continu en temps real durant el procés d’incineració i de neteja de gasos d’escapament. És per això que les filosofies de control són difícils d’optimitzar considerant la reducció d’emissió d’aquests contaminants. Aquesta investigació estableix un model matemàtic capaç de predir l’emissió atmosfèrica de PCDD/Fs en processos d’incineració, basada en variables de procés com la temperatura, el contingut d’oxigen, la composició del residu o el contingut en clor i metalls. Aquest model combina un model cinètic de formació de PCDD/Fs amb un model del procés d’incineració (usant ASPEN HYSYS) que determina tot el balanç de matèria i energia; convertint així la quantitat de PCDD/Fs generades (en massa per massa de residu incinerada) en un valor d’emissió atmosfèrica (en massa de contaminant per volum de gas de combustió emès en condicions normals). Amb l’objectiu de simplificar aquest model, la quantitat de congèneres de PCDD/F inclosos al model es redueix a només aquells als que la seva formació es considera linealment independent. Aquest estudi es realitza amb un conjunt de dades d’emissions industrials, i després es revisa, i els paràmetres del model obtingut es reajusten i es validen estadísticament amb una mescla de dades d’origen industrial i d’experimentació en laboratori.La producción de Residuo Sólido Urbano (RSU) no ha cesado en su incremento, en los últimos 20 años, en la mayor parte de países de la UE. Su gestión, adaptada a la filosofía de la Economía Circular que ha adoptado la UE, es uno de los retos ambientales más significativos que la sociedad deberá resolver en los próximos años. Desde que el vertido de residuos ha sido claramente definido como la última opción de gestión, e incluso señalada como una opción a evitar, el uso de incineradoras de RSU con recuperación de energía han ido ganando protagonismo como medida de gestión de residuos. La formación de dibenzo-p-dioxinas y dibenzofuranos policlorados (PCDD/Fs) se considera como uno de los problemas ambientales relacionados con la incineración de RSU. Esta familia de moléculas, que han sido identificadas como extremadamente tóxicas, son complejas de analizar en continuo durante el proceso de incineración y lavado de gases. Es por esto que las filosofías de control son difíciles de optimizar considerando la reducción de la emisión de estos contaminantes. En esta investigación se establece un modelo matemático que estima la emisión atmosférica de PCDD/Fs en procesos de incineración, basada en variables de proceso como la temperatura, el contenido de oxígeno, la composición del residuo o el contenido en cloro y metales. Este modelo combina un modelo cinético de formación de PCDD/Fs y un modelo del proceso de incineración (usando ASPEN HYSYS) que determina todo el balance de materia y energía; convirtiendo así la cantidad de PCDD/Fs generadas (en masa de contaminante por masa de residuo incinerado) en un valor de emisión atmosférica (en masa de contaminante por volumen de gas de combustión emitido en condiciones normales). Con el objetivo de simplificar este modelo, la cantidad de congéneres de PCDD/F incluidos en el modelo se reduce a solamente aquellos cuya formación se considera linealmente independiente. Este estudio se realiza con un conjunto de datos de emisiones industriales, y luego se revisa, y los parámetros del modelo se reajustan y validan estadísticamente, con una mezcla de datos de origen industrial y de experimentación en laboratorio.Municipal Solid Waste (MSW) generation has been increasing in the last 20 years in most countries in the EU. Its management, under the philosophy of the Circular Economy that the EU has adopted, is an important environmental challenge that the society must solve in the years to come. Since landfilling has been clearly stated as the last option to implement, and promoted to avoid, the use of MSW incinerators with energy recovery has been continuously increasing. The formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) has been identified as one of the environmental issues related to MSW incineration. This family of molecules, which are demonstrated to be extremely toxic, are complex to monitor in real time during the execution of the incinerating process and the flue-gas cleaning. Thus, it is difficult to establish a control philosophy on the furnace parameters and the flue-gas cleaning system that optimizes its capture and reduces its formation. This investigation establishes a mathematical model capable to predict the atmospheric emission of PCDD/Fs of a waste incineration process, based on process variables such as temperature, oxygen content, waste composition and chlorine and metals content. This model combines a kinetic model of formation of PCDD/Fs with a process model (using ASPEN HYSYS) that is able to determine all of the heat and material balance and convert the PCDD/Fs formation (in mass production per mass of waste incinerated) to an atmospheric emission (in mass production per volume flow of flue-gas at normal conditions). In order to optimize this model, the number of PCDD/F congeners included in the model are reduced to only those whose formation is considered as linearly independent. This study is performed with a set of industrial data. The parameters of the model obtained were reviewed and statistically validated and determined with a mixture of industrial and laboratory-scale data

Diapycnal and isopycnal mixing in the western sector of the South Scotia Ridge

Trabajo presentado en el 2º Encuentro de Oceanografía Física, "Conociendo los mares para el beneficio de la sociedad", celebrado del 14 al 16 de noviembre de 2012 en Madrid (España)Peer Reviewe

The ESASSI-08 cruise in the South Scotia Ridge region: An inverse model property-transport analysis over the Ridge

Póster presentado en EGU General Assembly 2010, celebrada en Viena (Austria), del 2 al 7 de mayo de 2010Peer Reviewe

Water mass pathways, transports, and biochemical properties over the South Scotia Ridge west of 50ºW

Póster presentado en la General Assembly 2011 de la European Geosciences Union (EGU), celebrada del 3 al 8 de abril de 2011 en Viena (Austria)Peer Reviewe

Water mass pathways, transports, and biochemical properties over the South Scotia Ridge west of 50ºW

Póster presentado en el VIII Simposio de Estudios Polares (8th Symposium on Polar Studies), celebrado del 7 al 9 de septiembre de 2011 en Palma de Mallorca (España)Peer Reviewe

On the Antarctic Slope Front and Current crossing of the South Scotia Ridge

Póster presentado en la 2012 General Assembly de la European Geosciences Union (EGU), celebrada del 22 al 27 de abril de 2012 en Viena (Austria)Peer Reviewe

On the outflow of dense ventilated slope water into the Scotia Sea west of the Orkney Passage

Póster presentado en el VIII Simposio de Estudios Polares (8th Symposium on Polar Studies), celebrado del 7 al 9 de septiembre de 2011 en Palma de Mallorca (España)Peer Reviewe

Kinetics of the formation and destruction of PCDD/Fs in a laboratory tubular furnace

A kinetic model has been developed for the formation of selected congeners of PCDD/Fs during the thermal decomposition of different wastes in a horizontal reactor. Previously published data on the decomposition of wastes have been correlated using a kinetic model that only considers process parameters, such as the presence of different amounts of oxygen in the atmosphere of reaction, chlorine and metals in the waste. The effect of both chlorine and metals is modelled through an equation assuming a “saturation effect”, i.e., that a certain amount of each substance produces the maximum rate, and that higher amounts do not increase the rate. The presence of oxygen is modelled by a destruction reaction over part of the PCDD/Fs produced. The model, which uses data from more than 64 experiments, correlated the emissions of three selected congeners: 1,2,3,6,7,8-HxCDD, OCDF and 2,3,7,8-TCDF, which are enough to estimate the total amount and toxicity of an emission