Fluidização de partículas de bagaço de laranja assistida pelo uso de sólidos inertes

• Autor(a) principal: Resende Filho, Paulo Eduardo
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/jspui/handle/riufs/17812
• topic: Engenharia química; Biomassa; Energia; Fontes alternativas de energia; Sólido inerte; Mistura binária; Leito fluidizado; Bioenergia; Biomass; Inert solid; Binary mixture; Fluidized bed; Bionergy; ENGENHARIAS::ENGENHARIA QUIMICA

The increasing energy demand is a strong indicator of a country's economic and social development. However, for its generation, in many cases, non-renewable sources of great environmental impact are used, raising the concern. In this scenario, as an ecological and renewable alternative, organic waste from the agro-industrial sectors is seen as an alternative form of energy supply. Orange bagasse, generated from the processing of orange juice, is a strong candidate for use as a source of biomass, especially in Brazil as it has one of the world's largest orange productions and generates tons of waste annually. However, to be used in this way, the bagasse has to go through a step that reduces its initial moisture content, since the calorific value is directly influenced by this parameter. Among the existing drying technologies, the fluidized bed has been widely used in biomass drying for energy purposes. To use this technology, it is a needed previously to study the fluid dynamics of the bed, in order to stablish the minimum fluidization conditions. One of the main characteristics of the fluidized bed is to promote intense contact between the fluid and the particles, thus intensifying the heat and mass transfer rates in drying. However, beds composed by monoparticles from orange biomass have poor fluidization quality, due to the channeling caused by strong cohesive interparticle forces. One way to improve the fluidization of biomass particles is to use inert particles. Thus, the objective of this work was to study the fluid dynamics of the binary mixture composed of orange bagasse particles and inert particles of sand or polyethylene in fluidized bed. To determine the characteristic curves, piezo-resistive MPX5010DP differential pressure transducers coupled with a properly calibrated and configured Arduino Uno programmable controller were used. A Scilab acquisition system was developed to assist in the collection and processing of data provided by the platform. The fluid dynamic tests were conducted based on a factorial design 3 2 , in order to evaluate the influence of the biomass mass fraction (5%, 10 % and 15%) and bagasse moisture (15%, 45% and 75%) on the air flow rate and pressure drop through the bed at the minimum fluidization conditions. The total bed mass was set at 1400 g. The particles were classified as Geldart D-type and the fluidization was classified as aggregative based on the calculated Froude number value. Although binary mixtures with polyethylene had the best average fluidization index (0.8452 ± 0.0162), binary mixtures with 0.93 mm sand as inert solid had the lowest mean minimum fluidization air flow rate (45.50 ± 7,30) m3 /h, requiring thus a lower power consumption to pump the gas in the fluidized bed.