https://ri.ufs.br/jspui/handle/riufs/2443 2026-09-04T02:45:13Z https://ri.ufs.br/jspui/handle/riufs/25886 Título: Características de fluidização de misturas binárias contendo casca residual de mandioca e areia Autor(es): Rocha, Raquel Estevez Abstract: The better management of natural resources has become a global agenda and in recent years there is a global trend towards an increase in the use of renewable energy sources. In this context, the conversion of biomass into energy has grown in importance, in order to replace the demand for fossil fuels, as well as to diversify energy sources. Cassava (Manihot esculenta Crantz) is one of the most prominent temporary crops in Brazil, with more than 18.1 million tons produced in 2021. All this productivity generates waste that most often does not have proper disposal. Among solid residues, the cassava peel represents a valuable source of biomass for the production of bioenergy due to its lignocellulosic characteristics. Fluidized bed technology appears as a potential alternative, both for drying as biomass pre-treatment, in order to reduce its high moisture content, and for thermochemical conversion processes. This technology, by promoting an intense mixing between the particles and the fluid, intensifies the rates of heat and mass transfer, and of conversion. To assist in the fluidization of different biomasses, inert particles have been commonly used. Therefore, given the scarcity of information in the literature on the application of the fluidized bed technique for the processing of residual cassava husk, the objective of this work was to investigate the fluid dynamic behavior of single components and binary mixtures containing biomass particles from cassava peel and sand particles in fluidized bed. The fluid dynamic tests were carried out in a typical fluidized bed with air at room temperature, binary mixtures of 1.29 mm biomass with sand of 1.29 mm and 0.93 mm, following a 33 factorial design, in order to evaluate the effects of the bed aspect ratio L/D (1, 1.5 and 2), of the volumetric fraction (25%, 50% and 75%) and of the moisture content of the biomass (10%, 42.5% and 75% b.u.), in addition to influence of the inert particle diameter on the fluidization parameters. Pressure drop and velocity data were measured using an U-tube differential manometer and an anemometer, respectively. The results for the binary mixtures showed that the bed aspect ratio influenced the behavior of the incipient and complete fluidization velocities. The moisture of the particles significantly affected all velocities, including the minimum fluidization, mainly as the volumetric proportion of biomass and the bed aspect ratio increased. The proportion of biomass affected moist and dried biomass in different ways and the velocities generally increased for the larger diameter inert. The slugging phenomenon seen for pure biomass beds did not occur with the binary mixtures, indicating an improvement in the fluidization quality of the mixture with the use of sand as inert, in line with the angle of repose data obtained. Based on the fluid dynamic analysis carried out, the most suitable operating conditions to obtain greater fluidization quality and stability, both for drying the wet cassava peel (75% b.u.) and for the thermochemical conversion processes of the dehydrated biomass (10% b.u.), were those using the binary mixture with the sand having the smallest particle diameter (0.93 mm), with 75% volumetric fraction of biomass and L/D ratio of 1.5. For perspectives of studies resulting from this line of research, there is the definition of the optimal operating conditions to increase the thermal efficiency of a fluidized bed dryer, having as reference the fluid dynamic data determined here, in addition to the application of cassava peel and quartz sand in a fluidized bed reactor. 2023-02-28T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/23647 Título: Estudo comparativo da utilização de resíduo de telhas cerâmicas e Moringa oleifera Lam. como etapa de finalização na clarificação de fermentado de cana-de-açúcar Autor(es): Nascimento, Isabella Santos Abstract: This study investigated the use of ceramic tile waste and the natural coagulant Moringa oleifera Lam. as sustainable and economical alternatives for the clarification of sugarcane alcoholic fermentate, traditionally done with bentonite clays. The ceramic tile waste was characterized through sieve analysis. Moringa seeds were prepared to act as a coagulant. Physical and chemical analyses were conducted on sugarcane juice, fermentate, fermentate with added moringa coagulant, and with added pulverized ceramic residues retained on sieves with mesh openings of 425 µm, 250 µm, 150 µm, and 75 µm. Tests were carried out regarding apparent color, turbidity, pH, total solids, and metals. The treated samples were also analyzed for alcohol content and BET testing. It was observed that all treatments contributed to the clarification of the sample, with emphasis on ceramic residues RC #425 µm and RC #250 µm, which demonstrated greater efficiency in reducing turbidity and apparent color. The treatment with Moringa, although effective in impurity removal, showed the greatest increase in electrical conductivity, indicating a significant release of soluble salts. Treatments with fermentation maintained relatively stable pH and conductivity values, acting moderately on the analyzed parameters. The combination of both materials demonstrated efficiency in clarification, resulting in a cleaner fermentate with lower environmental cost. This process aligns with SDG 12 (Responsible Consumption and Production), showing itself as a promising and viable alternative for the alcoholic beverage industry and the biofuel sector. 2025-08-27T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/21156 Título: Síntese e caracterização de carvão ativado de vagem de Moringa Oleifera Lam e avaliação do seu desempenho na remoção de óleos e graxas Autor(es): Bispo, Mirele dos Santos Abstract: The high volume and chemical composition of oily wastewater produced by the petroleum industry are a major problem in this sector, because .improper waste disposal may result in high ecological damage. Therefore, the treatment of this water is highly important, with many techniques being applied in the industry. A very widespread and effective technology used in water treatment contaminated by organic compounds is adsorption. In this context, this study investigated an application of three activated carbons in the removal of oil and grease present in the produced water. The precursor material was the Moringa oleifera Lam and the influence of activating agents such as zinc chloride (ZnCl2), phosphoric acid (H3PO4) and sodium hydroxide (NaOH) was investigated. The adsorbents obtained were characterized by the ash content, elemental analysis (CHN), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TG / DTG). The kinetic study showed that the equilibrium was reached around 10 minutes for all activated carbons. Additionally, the adsorbents were better represented by the pseudo-second order kinetic model. The sodium hydroxide activated carbon showed an unfavorable behavior to adsorption, while the phosphoric acid activated carbon showed a favorable behavior with adsorption capacity of 294.41 mg g-1 and removal efficiency equal to 95%. In addition, its chemical equilibrium was described by Langmuir isotherm, suggesting chemical adsorption. Freundlich isotherm adjusted well to experimental adsorption data for zinc chloride activated carbon, achieving a reduction in oil and grease content of 95%. The study indicated a great applicability potential of activated carbon with phosphoric acid for the removal of oil and grease from the studied effluent. 2019-12-17T00:00:00Z https://ri.ufs.br/jspui/handle/riufs/21155 Título: Projeto, construção e avaliação da performance de um secador solar híbrido para a secagem de entrecasca de mandioca Autor(es): Andrade, Keyse Santos Abstract: The cassava inner bark is a starch-rich residue, which allows its application in several areas. It also has great potential for the production of biofuels, such as bio-oil, biogas or biochar. However, the proper use of this biomass is hindered due to its high moisture content, thus requiring drying as a pre-treatment operation. Despite numerous studies on the drying of different types of biomass, information regarding cassava peel is scarce in the literature. In the search for efficient drying technologies that can add value to cassava processing waste at competitive costs, solar drying emerges as a green, sustainable and economically viable technology. Within this context, the objective of this work was to construct and evaluate the performance of a solar dryer operating in active and indirect modes, as well as in a hybrid mode, where forced convection of air heated by solar energy is combined with infrared radiation (IR) for drying cassava inner bark. The performance of the dryer was analyzed in terms of the drying kinetics of the biomass and the efficiencies of the solar collector and the drying process itself. Two air velocities, 1.3 and 3.7 m/s, were used in both operating modes. In the hybrid mode, the power of the infrared radiation source was 50 W. During the experiments, solar irradiation intensity, collector temperature, air temperatures, and relative humidities along the dryer, as well as biomass mass and temperature, were measured. The collector temperature, air temperatures and relative humidities showed consistent values, following the behavior of solar irradiation. The forced airflow over a corrugated aluminum absorber plate promoted an increase in air temperature between 5.2 and 13.7°C, with the highest heating observed at 1.3 m/s, although the collector efficiency and drying rate were lower. The use of infrared radiation as an auxiliary heating source reduced drying time but increased energy consumption, leading to lower efficiency in the hybrid drying mode. Thus, in terms of cost and efficiency, the best performance of the developed solar dryer was achieved in the indirect-active mode, with an air velocity of 3.7 m/s, where a target moisture content of approximately 15% (wet basis) was reached in 260 minutes of drying, with an efficiency of 10.5%. 2024-08-30T00:00:00Z