Study of the Behaviour of a Catalytic Ceramic Candle Filter in a Lab-Scale Unit at High Temperatures

Abstract

Solid particles and tars are among the non-desirable products of synthesis gas produced during biomass gasification. Removal of fly ashes is necessary in order to comply with emission limits as well as avoid their deposition in downstream units. Condensation of tars, on the other side, can cause clogging. A catalytic hot gas filter can remove both solids and tars, when operating at temperatures as high as 850• C. Catalytic hot gas filter elements are under development in order to solve this issue.

Catalytic Activity in Naphthalene Reforming of Two Types of Catalytic Filters for Hot Gas Cleaning of Biomass-Derived Syngas

“…A long-term test under these conditions is not of interest for a correlation until then, when the first real tar conversion results of the catalytic filter candle with the integrated Mg6Ni(S) catalyst including the tar compound analysis at tar inlet contents of ≤5 g/Nm 3 are available. The determination of tar compound conversions under real gas conditions is the target of two ongoing pilot tests at 800 °C in a catalytic filter downstream of the BFB gasifier at the TU Delft, where already model gas tests have been performed, and in the bench-scale gasifier of the university of Teramo, where the catalytic filter candle has been integrated in the gasifier freeboard. , …”

“…After the first scale-up of this procedure up to 1.5 m candle length in the previous work, catalytic performances of 97% naphthalene conversion under H 2 S-free conditions and 58% in the presence of 100 ppmv H 2 S were measured by means of a candle segment in model biomass gasification gas with 12 vol % water and a naphthalene inlet content of 5 g/Nm 3 . Applying another model biomass gasification gas with 30 vol % water and a naphthalene content of 1.63 g/Nm 3 , a similar activity of 99.1% at 800 °C was measured on a 250 mm long candle with the same catalytic layer composition . With respect to an improvement in the catalytic activity in the presence of H 2 S, in this work, five new tar reforming catalytic filter candles with a catalytic layer design are examined for their catalytic activity in the presence and absence of H 2 S by examining the effect of different MgO-containing catalyst support layers and NiO loadings.…”

Fluidized Bed Gasification as a Mature And Reliable Technology for the Production of Bio-Syngas and Applied in the Production of Liquid Transportation Fuels—A Review

“…Catalytic hot gas filtration (so a combined particle removal and hydrocarbon reforming step) was investigated by Simeone et al [120] using model gas and tar compounds, and by Rapagna et al [121] using a ceramic candle filter installed directly in the freeboard of a small laboratory-scale steam-blown bubbling fluidized bed. Both investigations showed promising results in terms of tar conversion.…”

Upgrading of Raw Gas from Biomass and Waste Gasification: Challenges and Opportunities

“…An interesting example is to integrate catalytic tar cracking in a barrier particulate filter. This was first proposed for combustion applications by Saracco and Montanaro [50] and further elaborated to gasification applications by research groups at Vrije Universiteit Brussel, Belgium [51][52][53][54][55], University of L'Aquila, Italy [56,57] and TU Delft, The Netherlands [58], all in cooperation with Pall Filtersystems GmbH Werk Schumacher, Crailsheim, Germany. Schematics of two different designs, (a) deposits of Ni/MgO catalyst onto the pore walls in a-alumina in a candle [52] and (b) a catalytically active fixed bed in a cylindrical catalytic filter element [53], are shown in Fig.…”