https://repositorio.ufpb.br/jspui/handle/123456789/11874 PPGEQ 2026-08-11T12:34:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38619 Título: Análise de desempenho de controladores preditivos com estratégia Hot Vapor Bypass em um processo de Destilação com Oscilação de Pressão (PSD) Autor(es): Soares, Priscila Veloso Nogueira Orientador: Morais Júnior, Arioston Araújo de Abstract: Pressure-swing distillation (PSD) is a promising alternative for the separation of azeotropic mixtures, such as acetonitrile–water, but its operation involves significant challenges due to strong variable coupling, nonlinearities, and sensitivity to disturbances. In this context, this work evaluated the performance of different predictive control strategies in a PSD plant with full heat integration and the use of the hot vapor bypass (HVP) strategy, applied to assist pressure control and improve stability and energy efficiency. Concepts related to azeotrope formation, separation strategies, pressure control alternatives, and the characteristics of conventional and predictive controllers, particularly the Extended Infinite Horizon Model Predictive Control (EIHMPC) and its variation with implicit feedforward action (EIHMPCFF), were explored in the theoretical framework. The process was simulated using Aspen Plus™ and Aspen Dynamics™, followed by dynamic model identification through open-loop disturbances and the development of multivariable models implemented in MATLAB®, where PID, LMPC, EIHMPC, and EIHMPCFF controllers were tested. Comparative analyses considered scenarios of disturbances in the feed to the low-pressure column and setpoint changes, evaluating response time, and disturbance rejection. The results showed that LMPC achieved better performance than PID, although it still presented steady-state deviations; EIHMPC corrected these limitations, ensuring greater stability and accuracy; and EIHMPCFF stood out by anticipating disturbance effects, providing faster responses with lower accumulated error. Therefore, it is concluded that EIHMPCFF was the best-performing controller, confirming the relevance of advanced predictive strategies for complex industrial processes. Editor: Universidade Federal da Paraíba Tipo: Dissertação 2025-07-31T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38618 Título: Caracterização de fluido de perfuração emulsionado e seu impacto na microbiota do solo Autor(es): Silva, Jénifer Laís Herculano da Orientador: Curbelo, Fabiola Dias da Silva Abstract: This study investigated components of emulsion-based drilling fluids, aiming to identify sources of contamination and assess their impact on soil microbiota. To minimize environmental damage, two sustainable fluids were formulated using mollusk shell powder (MSP) as a filtrate reducer and saponified coconut oil (SCO) as a surfactant. The combination of these components ensured a stable emulsion and a reduction in filtrate volume without significantly compromising the viability of soil microorganisms. Microbiological analysis indicated that MSP and the viscosifying aqueous solution (GX) were the main contaminants, with results of 5.50×10² and 1.31×10⁵ CFU/mL respectively, while SCO exhibited bactericidal activity, with no microbial growth observed on the analyzed plates, contributing to reduced microbiological contamination. The fluids were tested in estuarine soil in accordance with ABNT NBR 10007:2004 standards, ensuring sample integrity. The results showed that the use of these bio-based additives in drilling fluids is an environmentally friendly alternative with no significant adverse effects on the viability of soil microorganisms. Thus, it was concluded that MSP and SCO are sustainable options for drilling fluid formulation, in compliance with current environmental regulations and the principles of the circular economy. Editor: Universidade Federal da Paraíba Tipo: Dissertação 2025-07-03T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38616 Título: Aplicação de biorreatores anaeróbios de membranas no tratamento biológico da água produzida do petróleo para produção de biogás Autor(es): Marinho, Camilla Eduarda Dias Orientador: Sena, Rennio Felix de Abstract: The produced water, a significant byproduct of oil extraction, represents a major environmental challenge due to its complex composition and high pollution potential. This study investigated the application of anaerobic membrane bioreactors (AnMBRs) in treating this effluent, evaluating their efficiency in removing organic contaminants and producing biogas. AnMBRs combine anaerobic digestion with membrane filtration, standing out for their low energy consumption, reduced sludge production, and potential for resource recovery. Factors such as pH (maintained between 6.4 and 7.0), temperature (32-35 ºC), and organic load were monitored to optimize microbial performance and biogas production. The experiment was divided into four phases, starting with 100% domestic sewage, followed by 20% produced water mixed with 80% domestic sewage, then a 50% mix of each, and concluding with 100% produced water, allowing gradual adaptation of the AnMBR microbiota. The results demonstrated high system efficiency, with organic matter removal exceeding 81% for COD and BOD, and over 94% for TSS. Biogas production varied between 0.25 and 0.35 m³ CH₄/kg COD, with a range in methane composition from 35% to 74%. In addition to meeting standards, the process proved promising for mitigating environmental impacts in the oil industry and other industrial sectors, reinforcing its contribution to the sustainable management of resources. Editor: Universidade Federal da Paraíba Tipo: Dissertação 2025-07-30T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38277 Título: Estudo cinético da pirólise do caroço de açaí (Euterpe Oleracea Mart.) uma primeira fase para obtenção de bio-óleo Autor(es): Silva, Daniel Arnóbio Dantas da Orientador: Silva, Giovanilton Ferreira da Abstract: The kinetic study of the pyrolysis reaction is characterized as a primordial step, since the knowledge of parameters such as activation energy (Eaα), pre-exponential factor (Aα) and reaction model (f(α)), allow us to glimpse the feasibility of the process, as well as the energy demand, and its dimensioning on an industrial scale. Therefore, the objective was to evaluate the potential of the process of fast pyrolysis of the açaí seed, the main residue of the açaí industry, for the production of bio-oil, through a kinetic study, and physical-chemical characterization by immediate analysis, thermogravimetry (TG ) and Fourier transform infrared spectroscopy (FTIR).The determination of the kinetic parameters of the reaction was carried out by applying the isoconversional methods of Friedman (FR), Ozawa-Flynn-Wall (OFW), and Kissinger-Akahira-Sunose (KAS) to thermogravimetric data obtained in five different heating ratios (2, 5, 20, 50, 75 and 100 oC.min-1 ) and N2 fluxes varying in 25, 50 and 75 mL.min- 1. It was possible to verify that, in relation to the chemical composition of the studied biomass, it can be said that it has promising characteristics if it is directed to the production of bio-oil, such as low moisture content (9.30%), high content of volatile material (83.5%) and low amount of ash (1.75%). The study of the thermal decomposition of the açaí seed in an inert atmosphere showed three characteristic regions of mass loss defined as drying, fast pyrolysis and slow pyrolysis, where it was possible to observe, respectively, mass losses for such regions of 11.91 ± 0.2 %, 77.71 ± 1.97 % and 9.01 ± 1.40%. The analysis of the variation of activation energy as a function of the conversion in N2 flux of 50 mL.min-1 , allowed to distinguish Eaα results for hemicellulose and cellulose in agreement with results reported in the literature. For the region of variation attributed to hemicellulose, the Eaα values were 177.00 ± 14.09 kJ.mol-1 , 167.32 ± 14.02 kJ.mol-1 and 166.30 ± 14.60 kJ.mol-1 , using the FR, FWO and KAS methods, respectively. For the variation zone attributed to the thermal decomposition of cellulose, the values obtained were 189.83 ± 6.67 kJ.mol-1 , 184.79 ± 10,12 kJ.mol-1 , and 184.29 ± 10.46 kJ.mol-1 , using the FR, FWO and KAS methods, respectively. In addition, the study of the influence of the flow of N2 submitted to the sample indicated that the reactivity of the constituents is modified, being observed the reduction of the value of the apparent activation energy with the increase of the flow of N2 25 mL.min-1 to 75 mL.min-1 , for all isoconversional methods applied. The results obtained showed that the açaí seed stands out as a promising biomass, where the kinetic parameters obtained are evidenced as important information for the advancement in the evaluation of the viability of the fast pyrolysis route to produce aviation biokerosene. Editor: Universidade Federal da Paraíba Tipo: Dissertação 2022-02-23T00:00:00Z