1. |
- Ruivo, L. C. M., et al.
(författare)
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Iron-based catalyst (Fe2-xNixTiO5) for tar decomposition in biomass gasification
- 2021
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 300
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a novel Fe2-xNixTiO5 catalyst for potential applications in biomass gasification gas cleaning/ upgrading was investigated. The material was successfully synthesized through combined mechanical activation and microwave firing. Catalytic steam reforming was studied in a fixed bed tubular reactor, using a mixture of toluene and naphthalene as model tar compounds as well as downstream a fluidized bed gasifier. Fe2-xNixTiO5 catalyst showed high activity in converting the model compounds at temperatures higher than 700 degrees C. The catalyst exhibited a tar conversion of 78% at 800 degrees C when exposed to biomass-derived gas from a bubbling fluidized bed gasifier. Nevertheless, the catalytic activity declined with increased time on stream due to structural changes in iron active phases, caused by redox conditions of the producer gas. Furthermore, thermodynamic calculations suggest that sulfur chemisorption on the nickel surface, may also contribute to the catalyst deactivation.
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2. |
- Pio, D. T., et al.
(författare)
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Tar formation during eucalyptus gasification in a bubbling fluidized bed reactor : Effect of feedstock and reactor bed composition
- 2021
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 229
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Tidskriftsartikel (refereegranskat)abstract
- Tar compounds are inevitably present in the raw producer gas from biomass gasification and currently represent the main barrier for the commercial breakthrough of gasification technologies. In the present work, tar concentration in the producer gas from direct gasification of distinct types of residual forest biomass from eucalyptus in a 5 kWth bubbling fluidized bed reactor was investigated. The influence of the feedstock chemical composition and gasifier operation time was evaluated. Average tar concentration values in the raw producer gas were between 1.5 and 13.3 g/Nm3, representing a tar production between 8.4 and 67.0 g tar/kg biomass db, which surpasses suggested tar concentration limits for various potential applications for the producer gas. Major average tar compounds present in the tar sampled from the raw producer gas were benzene (47.1 %wt), toluene (21.6 %wt), naphthalene (10 %wt) and indene (6.4 %wt). A significant decay of the tar concentration in the producer gas was observed with increasing gasifier operation time, namely up to 50% within 45 min of operation, indicating its dependency on inorganics (e.g., CaCO3, KCl, maximum 5.5 %wt) and solid carbon (maximum 22.7 %wt) accumulation in the reactor bed.
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