Gaseificação de carvões nacionais com vapor de água visando a produção de gás de síntese

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2013.The steam gasification of Brazilian coal chars, subbituminous and bituminous, were investigated using a thermobalance in a temperature range of 1073-1173 K and pressure range of 1-20 bar. The operating variables used were in agreement with differential reactor and free diffusion limitations. The coal char samples were characterized, and the effects of temperature, total system pressure, parcial pressure and hidrogen on the kinetics of steam gasification were determined. The non-reactive core model was the one that best described the gasification reactions, at conditions studied, for conversions between 5-80%. For these coals and temperature range studied between 800 and 900 ° C, 1 bar, the activation energies were found to be 119.2 kJ?mol-1 and 170 kJ?mol-1 and pre-exponential factor were determined to be 4,10?105 e 4,55?103 min-1, respectively. Based on these parameters was determined the coal reactivity: CMRS-02 > CMSC-04 > CMSC-02 > CMSC-01. The higher reactivity for coal CMRS-02 was ascribed to the coal rank and vitrinite content. Regarding the effect of temperature, total pressure of the system and parcial pressure of steam on the reaction rate, the results showed that these effects were higher for bituminous coals, as the rank coal has more influence on the rate of reaction. The presence of hidrogen strongly inhibits the char-steam gasification reactions. The gases formed were H2, CO2and CO and the molar ratio H2/CO between 1,5 and 2 indicates that the syngas produced is promising for Fischer-Tropsch synthesis

Simultaneous production of mesoporous biochar and palmitic acid by pyrolysis of brewing industry wastes

Pyrolysis of malt bagasse was carried out to obtain simultaneously a mesoporous biochar and an oil fraction rich in palmitic acid. The best result for biochar production was at 500 °C with holding time of 10 min. The yields of biochar and pyrolytic oil in this condition were, 29.7 and 33.9 wt%, respectively. The pyrolysis temperature and holding time influenced the yields of the products. An increase in pyrolysis temperature (from 500 to 700 °C) and holding time (from 10 to 50 min) caused a decrease in biochar yield, a reduction in the volatile matter content and an increase in the amount of ash. Additionally, in the range studied in this work, the increase of the pyrolysis temperature caused a decrease in the specific surface area and total pore volume of the biochar. Meanwhile, the biochar presented interesting functional groups and a mesoporous character, which can be a precursor to obtain adsorbents, or even, be used as adsorbent. The pyrolytic oil was composed of oxygenated aromatic compounds, the main fraction being palmitic acid (27.3%), which can be used in a number of applications, including biodiesel production. This work demonstrated that an available and problematic waste, malt bagasse, can be converted simultaneously into a mesoporous biochar and, into a pyrolytic oil rich in palmitic acid. Biochar and pyrolytic oil, in turn, are products of great value and can be applied in several fields

Adsorption of ibuprofen, ketoprofen, and paracetamol onto activated carbon prepared from effluent treatment plant sludge of the beverage industry

The presence of emerging contaminants such as pharmaceuticals in aquatic means presents as a serious threat, since their real consequences for the environment and human health are not well known. Therefore, this work consisted of preparing and characterize sludge-derived activated carbons (beverage sludge activated carbon – BSAC and acid-treated beverage sludge activated carbon - ABSAC) to investigate their use in the pharmaceuticals adsorption in aqueous media. The morphology study has demonstrated that ABSAC, unlike BSAC, exhibited an abundant porous structure, with smaller particles and bigger roughness. Adsorption results indicated that the ABSAC was more effective that BSAC, since it presented superior surface area (642 m2 g-1) and total pore volume (0.485 cm3 g-1) values. Pseudo-second-order kinetic model was more suitable to predict experimental data. Sips model best described the equilibrium data, with maximum adsorption capacities of 145, 105, and 57 mg g-1 for paracetamol, ibuprofen, and ketoprofen, respectively. Besides, the sludge-derived adsorbent was highly efficient in the treatment of a simulated drug effluent, removing 85.16% of the pharmaceutical compounds. Therefore, the material prepared in this work possesses intrinsic characteristics that make it a remarkable adsorbent to be applied in the treatment of pharmaceutical contaminants contained in industrial wastewater

Treatment of effluents containing 2-chlorophenol by adsorption onto chemically and physically activated biochars

The application of adsorption using biochars for the remediation of effluents containing emerging contaminants, including chlorophenols, is a hotspot and trend development in the literature. This treatment is more interesting when using readily available wastes and at no cost, such as malt bagasse, for example. Here, the biochars were produced from malt bagasse, by physical and chemical activation (with CO2 and ZnCl2, respectively) and employed as adsorbents in the remediation of effluents containing 2-chlorophenol. Results revealed that the activated biochars have mesoporous structures and surface areas of 161 m² g-1 (CO2) and 545 m² g-1 (ZnCl2). For both activated biochars, adsorption of 2-chlorophenol was favored under acid conditions, with the highest adsorption capacities found using ZnCl2-activated biochar. The maximum adsorption capacity using ZnCl2-activated biochar was 150 mg g-1. The process was endothermic and spontaneous. ZnCl2-activated biochar exhibited an efficiency of 98% (using a dosage of 10 g L-1) in the treatment of industrial effluents containing 2-chlorophenol.La aplicación de la adsorción mediante biocarros para la remediación de efluentes que contienen contaminantes emergentes, incluidos los clorofenoles, es un punto crítico y un desarrollo de tendencia en la literatura. Este tratamiento es más interesante cuando se utilizan residuos fácilmente disponibles y sin costo, como el bagazo de malta, por ejemplo. Aquí, los biocarros se produjeron a partir de bagazo de malta, mediante activación física y química (con CO2 y ZnCl2, respectivamente) y se emplearon como adsorbentes en la remediación de efluentes que contienen 2-clorofenol. Los resultados revelaron que los biocarros activados tienen estructuras mesoporosas y áreas superficiales de 161 m² g-1 (CO2) y 545 m² g-1 (ZnCl2). Para ambos biocarros activados, la adsorción de 2-clorofenol se vio favorecida en condiciones ácidas, con las capacidades de adsorción más altas encontradas utilizando biocarbón activado con ZnCl2. La capacidad máxima de adsorción usando biocarbón activado con ZnCl2 fue de 150 mg g-1. El proceso fue endotérmico y espontáneo. El biocarbón activado con ZnCl2 exhibió una eficiencia del 98% (usando una dosis de 10 g L-1) en el tratamiento de efluentes industriales que contienen 2-clorofenol

South American Expert Roundtable : increasing adaptive governance capacity for coping with unintended side effects of digital transformation

This paper presents the main messages of a South American expert roundtable (ERT) on the unintended side effects (unseens) of digital transformation. The input of the ERT comprised 39 propositions from 20 experts representing 11 different perspectives. The two-day ERT discussed the main drivers and challenges as well as vulnerabilities or unseens and provided suggestions for: (i) the mechanisms underlying major unseens; (ii) understanding possible ways in which rebound effects of digital transformation may become the subject of overarching research in three main categories of impact: development factors, society, and individuals; and (iii) a set of potential action domains for transdisciplinary follow-up processes, including a case study in Brazil. A content analysis of the propositions and related mechanisms provided insights in the genesis of unseens by identifying 15 interrelated causal mechanisms related to critical issues/concerns. Additionally, a cluster analysis (CLA) was applied to structure the challenges and critical developments in South America. The discussion elaborated the genesis, dynamics, and impacts of (groups of) unseens such as the digital divide (that affects most countries that are not included in the development of digital business, management, production, etc. tools) or the challenge of restructuring small- and medium-sized enterprises (whose service is digitally substituted by digital devices). We identify specific issues and effects (for most South American countries) such as lack of governmental structure, challenging geographical structures (e.g., inclusion in high-performance transmission power), or the digital readiness of (wide parts) of society. One scientific contribution of the paper is related to the presented methodology that provides insights into the phenomena, the causal chains underlying “wanted/positive” and “unwanted/negative” effects, and the processes and mechanisms of societal changes caused by digitalization

Minimizing the gender disparity in the area of Exact Sciences, Engineering and Computing: the impact of the University on the daily lives of students from public schools from Santa Maria city, Brazil

El objetivo principal de este trabajo fue dar a conocer las actividades de un proyecto de extensión, denominado UniEscola, desarrollado en alianza entre la Universidad Federal de Santa María, Brasil, y escuelas en las afueras de la ciudad de Santa María ubicadas en Rio Grande do Sul. El proyecto trae como objetivo principal despertar el interés de las niñas, alumnas de las escuelas públicas en las áreas de ciencias exactas, ingeniería e informática, potenciando sus vocaciones científicas, ofreciéndoles aprendizajes relacionados con su vida diaria y formándolas para el mundo laboral y el protagonismo social. Durante este período se llevaron a cabo diversas actividades, como cursos, talleres, charlas, actividades de iniciación científica, visitas. Como principales resultados, se puede destacar la experiencia de los participantes en el ámbito académico, desmitificando estas áreas y fomentando la extensión universitaria. Finalmente, el principal resultado fue la búsqueda y aplicación de conocimientos tanto por parte de los estudiantes de la escuela como de los universitarios.The main objective of this work was to publicize the activities of an extension project, called UniEscola, developed in partnership between the Federal University of Santa Maria, Brazil, and schools on the outskirts of the city of Santa Maria located in Rio Grande do Sul. The project brings as a main goal to awaken the interest of girls, students of public schools in the areas of exact sciences, engineering and computing, enhancing their scientific vocations, offering them learnings related to their daily life and training them for the world of work and social protagonism. Several activities were carried out during this period, such as courses, workshops, lectures, scientific initiation activities, visits. As main results, the experience of the participants in the academic environment, demystification of these areas and encouragement of university extension can be highlighted. Finally, the main result was the search and application of knowledge by both school students and university participants.O objetivo principal deste trabalho foi divulgar as atividades de um projeto de extensão, chamado UniEscola, desenvolvido em parceria entre a Universidade Federal de Santa Maria, Brasil, e escolas da periferia da cidade de Santa Maria localizada no Rio Grande do Sul. O projeto traz como meta principal despertar o interesse das meninas, estudantes de escolas públicas pelas áreas de ciências exatas, engenharia e computação potencializando suas vocações científicas, oferecendo-lhes aprendizagens relacionadas à sua vida diária e capacitando-as para o mundo do trabalho e protagonismo social. Diversas atividades foram realizadas durante este período, como por exemplo, cursos, oficinas, palestras, atividades de iniciação científica, visitas. Como principais resultados podem-se se destacar a vivência das participantes no meio acadêmico, desmistificação destas áreas e incentivo a extensão universitária. E por fim o principal resultado foi a busca e aplicação de conhecimentos tanto por parte das alunas das escolas quanto pelas participantes da universidade

Minimização da disparidade de gênero na área de Ciências Exatas, Engenharias e Computação: o impacto da extensão universitária no cotidiano de alunas de escolas públicas na cidade de Santa Maria, Brasil

The main objective of this work was to publicize the activities of an extension project, called UniEscola, developed in partnership between the Federal University of Santa Maria, Brazil, and schools on the outskirts of the city of Santa Maria located in Rio Grande do Sul. The project brings as a main goal to awaken the interest of girls, students of public schools in the areas of exact sciences, engineering and computing, enhancing their scientific vocations, offering them learnings related to their daily life and training them for the world of work and social protagonism. Several activities were carried out during this period, such as courses, workshops, lectures, scientific initiation activities, visits. As main results, the experience of the participants in the academic environment, demystification of these areas and encouragement of university extension can be highlighted. Finally, the main result was the search and application of knowledge by both school students and university participants.O objetivo principal deste trabalho foi divulgar as atividades de um projeto de extensão, chamado UniEscola, desenvolvido em parceria entre a Universidade Federal de Santa Maria, Brasil, e escolas da periferia da cidade de Santa Maria localizada no Rio Grande do Sul. O projeto traz como meta principal despertar o interesse das meninas, estudantes de escolas públicas pelas áreas de ciências exatas, engenharia e computação potencializando suas vocações científicas, oferecendo-lhes aprendizagens relacionadas à sua vida diária e capacitando-as para o mundo do trabalho e protagonismo social. Diversas atividades foram realizadas durante este período, como por exemplo, cursos, oficinas, palestras, atividades de iniciação científica, visitas. Como principais resultados podem-se se destacar a vivência das participantes no meio acadêmico, desmistificação destas áreas e incentivo a extensão universitária. E por fim o principal resultado foi a busca e aplicação de conhecimentos tanto por parte das alunas das escolas quanto pelas participantes da universidade.El objetivo principal de este trabajo fue dar a conocer las actividades de un proyecto de extensión, denominado UniEscola, desarrollado en alianza entre la Universidad Federal de Santa María, Brasil, y escuelas en las afueras de la ciudad de Santa María ubicadas en Rio Grande do Sul. El proyecto trae como objetivo principal despertar el interés de las niñas, alumnas de las escuelas públicas en las áreas de ciencias exactas, ingeniería e informática, potenciando sus vocaciones científicas, ofreciéndoles aprendizajes relacionados con su vida diaria y formándolas para el mundo laboral y el protagonismo social. Durante este período se llevaron a cabo diversas actividades, como cursos, talleres, charlas, actividades de iniciación científica, visitas. Como principales resultados, se puede destacar la experiencia de los participantes en el ámbito académico, desmitificando estas áreas y fomentando la extensión universitaria. Finalmente, el principal resultado fue la búsqueda y aplicación de conocimientos tanto por parte de los estudiantes de la escuela como de los universitarios