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Abstract(s)
Com o passar dos anos o consumo de combustíveis tem aumentado, bem como a procura de novas fontes de energia. A valorização de resíduos, como a biomassa, pode ser feita usando processos como a combustão, a gaseificação ou a pirólise.
A presente dissertação foi realizada com o apoio da empresa INCBIO e teve como objetivo o dimensionamento de um reator piloto para pirolise de biomassa de modo a maximizar a produção de bio-óleo. Dentro dos tipos de pirólise escolheu-se a pirólise rápida, pois desta maneira a quantidade de bio-óleo será maximizada. Escolheu-se um reator de leito fluidizado borbulhante e a biomassa foi o bagaço de azeitona.
Com base nos cálculos efetuados, foi escolhida uma velocidade de fluidização de 0,14 m/s, correspondente a um caudal de azoto de 3,96 m3 /h (500 °C e 1 atm). Foram usados 1,5 kg de areia com um diâmetro de 375 µm, enquanto que para a biomassa foi assumido um caudal de 0,250 kg/s e o diâmetro médio das partículas foi de 2 mm.
O diâmetro interno do reator de pirólise será de 0,10 m e a altura de 1,43 m. Dimensionou-se um distribuidor de chapa perfurada que terá 145 orifícios. O topo da coluna está ligado a um ciclone onde será feita a recolha das partículas de carbonizado, tendo este um diâmetro de 26,9 mm.
Por fim, o reator necessita que lhe seja fornecida de uma potência de 205,6 kW. No condensador terá que ser trocada uma potência térmica de 201,4 kW, usando como fluido de arrefecimento água a 20 °C e um caudal de 1 kg/s. A área de transferência de calor necessária para esta troca é de 2,5 m2.
Over the years fuel consumption has increased, as well as the demand for new energy sources. The recovery of waste, such as biomass, can be done by using processes like combustion, gasification or pyrolysis. The present dissertation was done with the support of the company INCBIO and its objective was to design a pilot reactor for pyrolysis of biomass. in order to maximize the production of bio-oil. Of the various types of pyrolysis, the fast pyrolysis was selected because. in this way, the amount of bio-oil is maximized. The type of reactor chosen was a bubbling fluidized bed and the biomass used was olive bagass. Based on the calculations performed, a fluidization velocity of 0,14 m/s was chosen, corresponding to a nitrogen flow rate of 3,96 m3 /h (500 °C and 1 atm). In the fluidized bed, 1,5 g of sand with a diameter of 375 μm was used while for the biomass a flow rate of 0,250 kg/s was assumed. The average particle diameter of the olive bagass was 2 mm. The reactor has an internal diameter of 0,10 m and a height of 1,43 m. At the base of the column, the perfurated distributor has 145 orifices. The top of column is connected to a cyclone where particle collection is made, having a diameter of 26,9 mm. Finally, the reactor requires a power of 205,6 kW. In the condenser, a thermal power of 201,4 kW has to be exchanged, using water at 20ºC as the cooling fluid and at a flow rate of 1 kg/s. The heat transfer area required for this exchange is 2,5 m2.
Over the years fuel consumption has increased, as well as the demand for new energy sources. The recovery of waste, such as biomass, can be done by using processes like combustion, gasification or pyrolysis. The present dissertation was done with the support of the company INCBIO and its objective was to design a pilot reactor for pyrolysis of biomass. in order to maximize the production of bio-oil. Of the various types of pyrolysis, the fast pyrolysis was selected because. in this way, the amount of bio-oil is maximized. The type of reactor chosen was a bubbling fluidized bed and the biomass used was olive bagass. Based on the calculations performed, a fluidization velocity of 0,14 m/s was chosen, corresponding to a nitrogen flow rate of 3,96 m3 /h (500 °C and 1 atm). In the fluidized bed, 1,5 g of sand with a diameter of 375 μm was used while for the biomass a flow rate of 0,250 kg/s was assumed. The average particle diameter of the olive bagass was 2 mm. The reactor has an internal diameter of 0,10 m and a height of 1,43 m. At the base of the column, the perfurated distributor has 145 orifices. The top of column is connected to a cyclone where particle collection is made, having a diameter of 26,9 mm. Finally, the reactor requires a power of 205,6 kW. In the condenser, a thermal power of 201,4 kW has to be exchanged, using water at 20ºC as the cooling fluid and at a flow rate of 1 kg/s. The heat transfer area required for this exchange is 2,5 m2.
Description
Keywords
Pirólise Biomassa Leito fluidizado Pyrolysis Biomass Fluidized bed