Controle e otimização de uma unidade de hidrodessulfurização de múltiplas correntes de diesel

The presence of contaminants such as sulfur, nitrogen and aromatics in diesel is strictly controlled, following specific regulations of the fuel sector. These components affect diesel quality, impacting pollutant emissions and product marketing. The most widely used process to meet diesel specifications is catalytic hydrogenation, specifically hydrotreatment (HDT). Brazilian legislation imposes the use of S10 diesel. In this thesis, a HDT unit of multiple diesel streams was studied using a phenomenological mathematical model of a trickle-bed reactor (TBR). Predictive control strategies (MPC) were implemented, searching for the product in the S10 diesel specification. A problem of optimization of the HDT process was proposed, solved by the interior point method, considering the hydrodesulfurization reaction. The optimization sought to minimize operating costs by keeping the sulfur content in the product below the maximum allowable value. A kinetic model of catalytic deactivation was tested in order to evaluate its effects in the diesel HDT process. With the control and optimization strategies, the contaminant levels reached values that meet the S10 diesel specification. Thus, the MPC controller presented satisfactory performance and, with the optimization, reached the optimized values of 404.09 US$/h of the cost function, 699 K of the TBR feed temperature, 0.21 cm/s of the superficial velocity of the hydrogen gas. In terms of optimization, the flow rates of oils A, B and C were 0.018 cm3 /s, 0.022 cm3 /s and 0.06 cm3 /s respectively, and the concentration of sulfur compounds resulting from mixing the oils in the feed was 302 ppm.A presença de contaminantes como enxofre, nitrogênio e aromáticos no diesel é rigorosamente controlada, seguindo regulamentações específicas do setor de combustíveis. Esses componentes afetam a qualidade do diesel, impactando nas emissões de poluentes e na comercialização do produto. O processo mais utilizado para atender às especificações do diesel é a hidrogenação catalítica, especificamente o hidrotratamento (HDT). A legislação brasileira impõe o uso do diesel S10. Nessa tese, uma unidade de HDT de múltiplas correntes de diesel foi estudada, usando um modelo matemático fenomenológico de um reator trifásico de leito gotejante (TBR, trickle-bed reactor). Estratégias de controle preditivo do processo (MPC) foram implementadas, buscando o produto na especificação do diesel S10. Um problema de otimização do processo de HDT foi proposto e resolvido pelo método do ponto interior, considerando a reação de hidrodessulfurização. A otimização buscou minimizar os custos operacionais, mantendo o teor de enxofre no produto abaixo do valor máximo permitido. Um modelo cinético da desativação catalítica foi testado, no intuito avaliar seus efeitos no processo de HDT de diesel. Com as estratégias de controle e otimização, os teores do contaminante atingiram valores que atendem a especificação do diesel S10. Assim, o controlador MPC apresentou desempenho satisfatório, e, com a otimização, chegou aos valores otimizados de 404,09 US$/h da função custo, de 699 K da temperatura de alimentação do TBR, de 0,21 cm/s da velocidade superficial do gás hidrogênio. Em termos de otimização, as vazões dos óleos A, B e C foram de, respectivamente, 0,018 cm3 /s, 0,022 cm3 /s e 0,06 cm3 /s, e a concentração de compostos sulfurados resultante da mistura dos óleos na alimentação foi de 302 ppm

A study on modelling, data reconciliation and optimal operation of hydrogen networks in oil refineries

Se ha llevado a cabo un estudio sobre la gestión óptima en tiempo real de redes de hidrógeno en refinerías de petróleo, con referencia a la refinería de Petronor perteneciente al grupo Repsol y situada en Muskiz (Vizcaya). La tesis consiste en la aplicación de técnicas bien conocidas y establecidas como el modelado de procesos y la optimización a un tema interesante en la actualidad: las redes de hidrógeno en refinerías de petróleo. Los resultados obtenidos son coherentes y robustos, y las soluciones alcanzadas pueden ser directamente aplicadas en la práctica industrial. El problema abordado tiene gran relevancia industrial, con el propósito general de mejorar la operación en tiempo real, ahorrar recursos en este caso materiales relativos al hidrógeno, y aumentar el conocimiento del sistema en la medida de lo posible. Asimismo se han desarrollado librerías en el entorno de simulación EcosimPro. Los objetivos de la tesis son: i) la estimación correcta tanto de variables medidas como de variables desconocidas de la red de hidrógeno; ii) la determinación de las condiciones óptimas de operación así como de las producciones óptimas; iii) la exploración de otros enfoques dirigidos a la operación óptima como la técnica de control self-optimizing; iv) la evaluación del interés y potencial aplicabilidad de modelos simplificados de las plantas para la predicción del consumo de hidrógeno en función de la carga de hidrocarburo.Departamento de Ingeniería de Sistemas y Automátic

Innovative Materials and Methods for the Removal of Pollutants from the Environment

The progress of society has led to an improvement of the quality of life of a significant number of people. On the other hand, anthropogenic pollution dramatically increased, with serious consequences for the environment and human health. Controlling and remedying environmental pollution is one of the main challenges of our century. Fundamental and applicative research are called to collaborate, involving scientists in the development of realistic and effective systems for the prevention and the removal of pollutants from the environment. Spreading knowledge is among the missions of researchers and this is the aim of this book, offering an updated view on innovative materials and methods for pollutant treatment. It is composed of 18 articles, among them 5 reviews and 13 original articles, dedicated to new adsorbent materials (inorganic, organic, and hybrid materials) for the capture of pollutant species and for their catalytic conversion into non-toxic substances, and to bioremediation approaches to treat contaminated media. Water, air, and soil pollution was investigated, both at the lab and large scale, with special relevance for wastewater treatments for the removal of heavy metals and organic pollutants. We are grateful to “Molecules” for the opportunity to edit the Special Issue on “Innovative Materials and Methods for the Removal of Pollutants from the Environment”. We created, for this book, an original cover image, dedicated to the efforts of chemistry to defend the beauty of environment, represented by flowers, against every prejudice that considers chemistry an enemy of life