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- Valorisation of Leather Wastes from the Footwear Industry via Pyrolysis: Product Yields and CharacterisationPublication . Silva, F.; Direito, D.; Pilão, R.; Ribeiro, A.M.; Silva, Felipe; Direito, Daniel; Pilão, Rosa Maria; Ribeiro, AlbinaThe footwear industry, although contributing positively to the Portuguese economy, generates a lot of residues including chromium tanned leather wastes. This study presents results on the slow pyrolysis of these residues at particle sizes between 5 and 6.3 mm and temperatures inside the reactor ranging from 444 to 875 °C. For this range of temperatures, char yield decreased from 36.2 to 28.1% and gas yield increased between 33.2 and 47.6%. The liquid phase yield was highest at 444 °C (30.6%) and then decreased to 24.3% at 875 °C. As the operating temperature increased, there was an increase in the ash content (15.8 to 21.6%) and a decrease in volatiles content (20.9–3.7%) of biochars. The higher heating values (HHV) of the chars were between 21.9 and 23.1 MJ/kg. Preliminary results show that an increase in particle size leads to a rise in char yield. The infrared analysis of the liquid phase indicated the presence of water, alcohols, phenols, carboxylic acids, alkanes, alkenes, and aromatics. The liquid phases had an average water content of 43%, densities between 1110 and 1120 kg/m3 and the HHV between 12.7 and 15.1 MJ/kg. The gases produced were analysed by gas chromatography. For 538 °C, the production of H2, CO, CH4 and CO2 was, respectively, 1.00, 0.37, 0.18 and 1.37 mol/kg of leather. At 875 °C, H2 was the most produced gas (2.74 mol/kg leather), followed by CO, CO2 and CH4 with quantities of 1.40, 1.26 and 0.42 mol/kg leather.
- Evaluation of MCP correlation algorithms applied to wind data seriesPublication . Moreira, A.; Rocha, T.; Mendonça, J.; Pilão, R.; Pinto, P.(Objectives) This work aimed to develop methodologies for analyzing statistical correlations among wind data series using various Measure-Correlate-Predict (MCP) methods, with the goal of selecting the most suitable method for extrapolating long-term data with minimal associated uncertainty. Furthermore, the study intends to investigate how the concurrent period used to build the correlation can affect the performance indicators of MCP methods.
- Valorisation of leather wastes from footwear industry via pyrolysis: Product yields and characterisationPublication . Silva, F.; Direito, D.; Pilão, R.; Ribeiro, A.M.(Objectives) The influence of temperature on the pyrolysis of leather trimmings from the footwear industry; Characterization of leather waste used in the pyrolysis process; The physical-chemical characterizations of biochar, bio-oil and non-condensable gases.
- Pirólise de agulhas de pinheiro: resultados preliminaresPublication . Nascimento, M.; Silva, F.; Pilão, R.; Neto, M.P.; Ribeiro, A.M.(Introdução) As florestas em Portugal ocupam uma área aproximada de 3 224 200 ha, apresentando como espécies predominantes o sobreiro, o pinheiro e o eucalipto (ICNF, 2021). Os pinheiros ocupam cerca de 28 % desta área e geram diversos resíduos, entre os quais as agulhas, que se não forem retiradas das florestas podem agravar o problema dos incêndios florestais (Omvesh et al., 2023). A energia proveniente de resíduos florestais pode ser transformada em combustíveis ou em outros produtos químicos através de processos termoquímicos, como a pirólise, onde há a formação de três fases distintas: o carbonizado, o bio-óleo e o gás (Basu, 2018).
- Gasification of animal fat using dolomite as particle bed in a downdraft fixed bed reactorPublication . Pilão, R.; Araujo, A.L.; Silva, F.T.; Ribeiro, A.M.; Campos, J.B.L.M.One of the wastes generated in the tanning industry is hide fleshings, which contains 40% of animal fat, currently being deposited in landfills. The objective of this work was to study the catalytic capacity of dolomite in the gasification of this waste. The tests were carried out in a downflow fixed bed reactor using steam as gasification agent and used as bed of particles, alumina, dolomite and a mixture of the two mate-rials. Tests were caried out at 750 ºC and 800 ºC and the gas obtained was quantified and analyzed by gas chromatography. The results obtained showed that dolomite improves the performance of the gasification process, with an increase in carbon and hydrogen conversion efficiencies, cold gas efficiency and dry gas yield with the use of dolomite. It was also possible to verify the catalytic capacity of this material in the cracking of hydrocarbons and its potential in promoting the production of H2. In addition, the use of the mixed bed allowed to improve the results of the gasification parameters obtained at 800 ºC without compromising the degradation of the dolomite verified at higher temperatures.