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  • Effect of catalyst on the producer gas composition from co-gasification of glycerol/fat mixtures
    Publication . Cruz, Amaro; Ramalho, Elisa; Ribeiro, Albina; Pilão, Rosa Maria
    In this work, steam reforming of crude glycerol and animal fat mixtures was studied. The tests were carried out at temperatures of 700 °C and 750 °C in a fixed bed reactor using activated alumina or dolomite particles, to evaluate the catalytic capacity of these minerals in the removal of tar from the producer gas. The gas produced was quantified and analyzed by gas chromatography, and it was concluded that its composition is greatly influenced by the bed material used. The results obtained showed that dolomite is more effective in reducing the tar content, evidencing its ability to catalyze the tar reform reactions and promoting the water-gas shift reaction. Consequently, using dolomite as a catalyst, a producer gas with 47–48 vol% in H and 27–30 vol% in CO2 was obtained, while using a bed of alumina particles, a gas with a high CO content (45–48 vol%) and lower H content (34–37 vol%) was produced.
  • Thermodynamic equilibrium modelling of glycerol gasification
    Publication . Almeida, Ana; Ramalho, Elisa; Ribeiro, Albina; Pinho, Carlos; Pilão, Rosa
    The modeling of the gasification process using the thermodynamic chemical equilibrium of the process is an important tool when it is intended to obtain preliminary results or to scale-up an experimental installation. In this work, the gasification process of crude glycerol using steam as the gasification agent was modeled using stoichiometric and non-stoichiometric chemical equi librium models. The effect of the gasification temperature on the equilibrium composition of the producer gas was evaluated. The simulation results were com pared with the experimental results obtained in a downdraft fixed bed reactor. The results obtained showed that the two models predict the equilibrium compo sition in a similar way. They also showed that the gasification reactor is operating under conditions deviating from chemical equilibrium.
  • Co-Gasification of Crude Glycerol/Animal Fat Mixtures
    Publication . Almeida, Ana F.; Pilão, Rosa Maria; Ribeiro, Albina; Ramalho, Elisa; Pinho, Carlos
    The aim of this work was to assess the technical viability of glycerol/fat co-gasification. The gasification performance was studied in a downflow fixed bed reactor using activated alumina particles as bed material and steam as oxidizing agent. The effect of gasification temperature, from 800 to 950 °C was studied with a feed mixture with 10% (w/w) of animal fat. The influence of fat incorporation on the feedstock in the overall gasification process was also performed, using 3% (w/w) and 5% (w/w) of fat in feed mixtures. Samples of dry gas from the gasifier were collected and analyzed by gas chromatography in order to determine the CO, CO2, CH4, and H2 content. The best results were obtained using the highest tested temperature, 950 °C, and using 3% (w/w) of animal fat in the feed mixture. The overall results revealed that the co-gasification of glycerol/animal fat mixtures seems to be a feasible technical option