Otimização de sistema integrado de produção de biocombustíveis e adsorventes sólidos de CO2 por co-peletização de hidrocarvões de resíduos sólidos orgânicos urbanos assistida por irradiação de micro-ondas
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Data
2021-01-07
Autores
Moreira, Bruno Rafael de Almeida
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Universidade Estadual Paulista (Unesp)
Resumo
A geração de resíduos sólidos urbanos (RSU) é progressiva. Dispô-los em aterros ou, simplesmente, descartá-los ao meio ambiente é insustentável. Convertê-los, termoquimicamente, em biocombustíveis e, ou, adsorventes sólidos de CO2 foi, portanto, o objetivo de pesquisa. À co-peletização, hidrocarbonizaram-se restos alimentares de domicílios, descartes hortifrutigranjeiros de supermercados e lodo por 1,00; 1,50 and 2,00 h, irradiando-os, ou não, posteriormente, por 0,05 ou 1,00 min, com, ou sem, adição de grafite, esterco bovino ou borra de café a 1,00 e 2,00 %. À classificação de produtos, por sistema inferencial neuro-fuzzy adaptativo e fuzzy C-means, avaliaram-se: comprimento, diâmetro, densidade aparente, poder calorífico superior, durabilidade, resistência à abrasão e carga hidráulica; área superficial, volume e dimensão fractal de microporos e capacidade de captura. Complementarmente, aproximaram-se dados termogravimétricos de cinética e termodinâmica de adsorção-sorção de pseudomodelos de primeira e segunda ordens, isotermas de Langmuir, Freundlich e Temkin, energia livre de Gibbs (ΔG°) e entalpia (ΔH°). Hidrocarvão de restos alimentares, com borra a 2,00%, sem irradiação, condicionou péletes à maior produção de energia por unidade de massa, 24,05 MJ kg-1, aproximadamente. Péletes de hidrocarvão de lodo, sem procedimentos intermediários, eram tão duráveis e calóricos quanto os de hidrocarvão de descartes hortifrutigranjeiros, porém, menos higroscópicos. Portanto, desde que o intervalo de tempo de hidrocarbonização fosse 2,00 h, aditivação e irradiação eram, absolutamente, dispensáveis à termoconversão de lodo. Pelas isotermas de Langmuir, Freundlich e Temkin, aplicação, ou não, de grafite a 2,00 % maximizaria adsorção (0,89585–0,92740 mmol g-1) de produtos de hidrocarbonização de 1,50 a 2,00 h de descartes hortifrutigranjeiros e lodo, com, ou sem, irradiação de 1,00 min, intensificando-a, expressivamente, sem, sequer, requerer significante quantidade de energia à sorção: 10,25–10,65 J mol-1. Independente de rota de conversão termoquímica e aditivo, valores de ΔG° e ΔH° eram negativos. Se energia de Gibbs e entalpia são negativos, então, adsorção é espontânea e exotérmica. As perspectivas de projeto são relevantes ao desenvolvimento e implementação de estratégias de valorização sustentável de RSU, convertendo-os, em péletes para unidades de produção de bioenergia e bioestruturas microporosas para sistemas de captura e estoque de gases pós-combustão
Generation of municipal solid waste (MSW) is growing significantly worldwide. Landfilling or simply discarding MSW at “off-site” is not sustainable, and can be expensive and wasteful. This study aimed at thermally converting organic fraction of MSW into fuel grade biosolids and adsorbents of CO2. The integrated process of manufacturing started with carbonizing either household “food trash”, residues of supermarkets or sludge, then, irradiating their hydrochars with or with no graphite, cattle manure or coffee filter cake at 1.00 and 2.00% as additives. The primary and secondary waste-to-energy pathways lasted for 1.00, 1.50 and 2.00 h, and 0.50 and 1.00 min, respectively. The variables to assist with classifying products on the soft computing techniques of adaptative neuro-fuzzy inference system and fuzzy C-means clustering approach precisely were length, diameter, apparent density, higher heating value (HHV), durability, resistance to abrasive and hydraulic forces, surface area, volume and fractal dimension of micropores, and capacity of capturing. The methods of applying stochastic statistics to fit thermogravimetry data for the kinetics and thermodynamics of adsorption-sorption were first-power and second-power pseudo-models, isotherms of Langmuir, Freundlich and Temkin, Gibbs energy (ΔG°) and enthalpy (ΔH°). The hydrochar from systematically processing food trash and 2.00% graphite in mixture, with no irradiation, enabled the biomass-to-solid fuels to the highest HHV, 24.05 MJ kg-1. Pellets of hydrochars from sludge and residues of supermarkets, without any intermediate procedure, had durability and calorific value at comparable rates, but they were distinct in hygroscopicity. As long as the holding time of carbonization is 2.00 h, addition and irradiation onto the sludge are likely unimportant to getting further improvements in both physicomechanical stability and fuel power. The isotherms of Langmuir, Freundlich and Temkin predicted adequately the addition of 2,00% graphite to be highly capable of maximizing adsorption (0,89585–0,92740 mmol g-1) by products from hydrocarbonization of residues from supermarkets and sludge, with 1,00 min irradiation, without requiring significant amount of energy to sorption (10,25–10,65 J mol-1). Irrespective of the thermochemical pathway, values of ΔG° and ΔH° were negative. If Gibbs energy and enthalpy are negative, then, the process of adsorption is spontaneous and exothermic. The major findings of this study should be of great relevance to valorization of MSW into high-performance pellets to heating-and-power units, and CO2-adsorbing biomaterials to the ongoing field of post-combustion solutions
Generation of municipal solid waste (MSW) is growing significantly worldwide. Landfilling or simply discarding MSW at “off-site” is not sustainable, and can be expensive and wasteful. This study aimed at thermally converting organic fraction of MSW into fuel grade biosolids and adsorbents of CO2. The integrated process of manufacturing started with carbonizing either household “food trash”, residues of supermarkets or sludge, then, irradiating their hydrochars with or with no graphite, cattle manure or coffee filter cake at 1.00 and 2.00% as additives. The primary and secondary waste-to-energy pathways lasted for 1.00, 1.50 and 2.00 h, and 0.50 and 1.00 min, respectively. The variables to assist with classifying products on the soft computing techniques of adaptative neuro-fuzzy inference system and fuzzy C-means clustering approach precisely were length, diameter, apparent density, higher heating value (HHV), durability, resistance to abrasive and hydraulic forces, surface area, volume and fractal dimension of micropores, and capacity of capturing. The methods of applying stochastic statistics to fit thermogravimetry data for the kinetics and thermodynamics of adsorption-sorption were first-power and second-power pseudo-models, isotherms of Langmuir, Freundlich and Temkin, Gibbs energy (ΔG°) and enthalpy (ΔH°). The hydrochar from systematically processing food trash and 2.00% graphite in mixture, with no irradiation, enabled the biomass-to-solid fuels to the highest HHV, 24.05 MJ kg-1. Pellets of hydrochars from sludge and residues of supermarkets, without any intermediate procedure, had durability and calorific value at comparable rates, but they were distinct in hygroscopicity. As long as the holding time of carbonization is 2.00 h, addition and irradiation onto the sludge are likely unimportant to getting further improvements in both physicomechanical stability and fuel power. The isotherms of Langmuir, Freundlich and Temkin predicted adequately the addition of 2,00% graphite to be highly capable of maximizing adsorption (0,89585–0,92740 mmol g-1) by products from hydrocarbonization of residues from supermarkets and sludge, with 1,00 min irradiation, without requiring significant amount of energy to sorption (10,25–10,65 J mol-1). Irrespective of the thermochemical pathway, values of ΔG° and ΔH° were negative. If Gibbs energy and enthalpy are negative, then, the process of adsorption is spontaneous and exothermic. The major findings of this study should be of great relevance to valorization of MSW into high-performance pellets to heating-and-power units, and CO2-adsorbing biomaterials to the ongoing field of post-combustion solutions
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Palavras-chave
Aditivos, Carbonização hidrotérmica, Cinética de adsorção, Péletes, Pós-combustão, RSU, Additives, Adsorption kinetics, Hydrothermal carbonization, MSW, Post-combustion