Browsing by Author "Ribeiro, A. M."
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- Effect of Temperature on the Gasification of Olive Bagasse ParticlesPublication . Almeida, A. F.; Vieira, M. S.; Neto, M. P.; Pereira, I. M.; Ribeiro, A. M.; Ribeiro, A. C.; Pilão, R. M.In this experimental study the evolution of gas characteristics during the gasification of olive bagasse particles was investigated using a semi-batch fluidized-bed gasifier. Sand particles with a mean diameter of 375 μm were used as bed material and an air flow was used as the fluidizing agent. Experimental tests were conducted with particles of diameter ranging from in 1.25 to 2 mm. The material was characterised through elemental and proximate analysis, and the higher heating value was also measured. In each run, the major components of the gas phase were identified as CO, CO2, H2, CH4, O2 and N2. Gaseous samples were collected and analysed by gas chromatography. The effect of bed temperature on gasification performance was studied. The tests were conducted at bed temperatures in the range of 700ºC to 900ºC Experimental results showed that gasification with air at higher temperatures favoured gas production, Results also showed increases in the gasification performance parameters as the bed temperature is increased.
- Pyrolysis of cork residues - preliminary resultsPublication . Teixeira, J; Direito, D.; Crispim, A.; Ribeiro, A. M.; Silva, L. M. S.The energy from renewable sources is a topic that has been widely discussed and studied, especially since the use of fossil fuels in industrial processes are the principal source of environmental pollution. ln, this context, the processes of biomass gasification and pyrolysis are alternatives for energy enhancement, especially in rural areas [1]. One novel area that has begun to be investigated is the use of cork residues. Gasification studies have been conducted using several) samples of residues obtained during different phases of the cork manufacturing process in order to test their ability to produce energy [2]. An alternative to gasification is pyrolysis, which involves the carbonization of solid materials in an inert atmosphere, resulting in three distinct products: gas, oil and a carbon-rich solid residue. The formation of pyrolytic products is influenced by the operating conditions and the characteristics of the raw material [3]. The aim of this study was to investigate possible innovation in the cork industry by analysing the efficiency of pyrolysis of natural cork waste and by identifying optimal operating conditions, and the characteristics of the products obtained. ln, this paper some preliminary results are reported
- Simulation of biomass gasification in circulating fluidized bed reactor by aspen plusPublication . Pinho, T. S.; Ribeiro, A. M.; Silva, L. M. S.Biomass is the fourth largest source of energy in the world. Many consider it to be the best option, with the greatest potential as an alternative energy supply which meets energy requiremen ts, for ensuring future fuel supply. Biomass energy resources are potentially the world's largest and most sustainable energy source, a renewable resource comprising 220 billion oven-dry tons (about 4500 EJ) of annual primary production [1]. lt is currently assumed that 5% of this energy could be mobilized to produce energy, i.e. a total of 225 EJ representing an energy equivalent ofmore than 5 billion tons ofoil equivalent, accounting for almost 50% ofthe world's total primary energy demand at present [2]. Hydrogen production is one of the most promising alternative energy technologies . The majority of experts consider that hydrogen has a significant role to play as an important energy carrier in the future energy sector [3]. Howe ver, it is a secondary form of energy that, like electricity, must be manufactured. A promising way to generate hydrogen is by thermochemical conversion of biom ass to synthe sis gas , consisting of a mixture of H2, CO, C0 2, CH.i, 0 2, N2 and tar. ln order to maximize H2 yield, an Or steam circulating fluidized bed (CFB) gasification process was proposed. For this purpose a computer simulation model was developed using the commercial chemical process simulator ASPEN Plus.