Analysis of bed agglomeration during gasification of wheat straw in a bubbling fluidised bed gasifier using mullite as bed material

Bhaird, Seán T. Mac an; Walsh, E. J.; Hemmingway, Phil; Maglinao, Amado L.; Capareda, Sergio C.; McDonnell, Kevin

doi:10.1016/j.powtec.2014.01.049

Cited by 30 publications

(10 citation statements)

References 25 publications

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“…Based on the different compound formations between combustion and gasification conditions, the oxidation state of the Fe oxides (Fe 2+ , Fe 3+ ) and formation of vivianite (Fe 3 (PO 4 ) 2 ) may be the dominating factor for the decreased IMT under gasification conditions. This case is important to consider since a large fraction of P in precipitated SS may be bound to Fe 2+ as vivianite [24], an important resource for P recovery [25].…”

Section: Melt Formationmentioning

confidence: 99%

Thermochemical equilibrium study of ash transformation during combustion and gasification of sewage sludge mixtures with agricultural residues with focus on the phosphorus speciation

Hannl

Sefidari

Kuba

et al. 2020

Biomass Conv. Bioref.

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The necessity of recycling anthropogenically used phosphorus to prevent aquatic eutrophication and decrease the economic dependency on mined phosphate ores encouraged recent research to identify potential alternative resource pools. One of these resource pools is the ash derived from the thermochemical conversion of sewage sludge. This ash is rich in phosphorus, although most of it is chemically associated in a way where it is not plant available. The aim of this work was to identify the P recovery potential of ashes from sewage sludge co-conversion processes with two types of agricultural residues, namely wheat straw (rich in K and Si) and sunflower husks (rich in K), employing thermodynamic equilibrium calculations. The results indicate that both the melting behavior and the formation of plant available phosphates can be enhanced by using these fuel blends in comparison with pure sewage sludge. This enhanced bioavailability of phosphates was mostly due to the predicted formation of K-bearing phosphates in the mixtures instead of Ca/Fe/Al phosphates in the pure sewage sludge ash. According to the calculations, gasification conditions could increase the degree of slag formation and enhance the volatilization of K in comparison with combustion conditions. Furthermore, the possibility of precipitating phosphates from ash melts could be shown. It is emphasized that the results of this theoretical study represent an idealized system since in practice, non-equilibrium influences such as kinetic limitations and formation of amorphous structures may be significant. However, applicability of thermodynamic calculations in the prediction of molten and solid phases may still guide experimental research to investigate the actual phosphate formation in the future.

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Section: Melt Formationmentioning

confidence: 99%

Thermochemical equilibrium study of ash transformation during combustion and gasification of sewage sludge mixtures with agricultural residues with focus on the phosphorus speciation

Hannl

Sefidari

Kuba

et al. 2020

Biomass Conv. Bioref.

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“…In general, larger amount of ash provides larger amount of AAEM and thus more active sites will be provided for the catalytic gasification of the coal. However, for the silica or silica-contained ashes, the aggregation of ash particles could occur on the coal surface more easily so that the total active surface area of the coal sample was decreased, resulting in the decrease of its reactivity [51,52]. …”

Section: Effect Of the Biomass Ash Amount On The Gas Production Rate mentioning

confidence: 99%

Promoting effect of various biomass ashes on the steam gasification of low-rank coal

et al. 2014

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“…The deposit formation involves a decrease in the heat exchanges as well as corrosion problems. The fluidized beds are sensible to bed material agglomeration, sintering and defluidisation, these problems may lead to total device failure [23]. A special care have to be taken when mixing WWS and waste, since their ash content can reach 30% mass fraction of dm to 40% mass fraction of dm [24,25].…”

Section: Introductionmentioning

confidence: 99%

Co-gasification of wastewater sludge and different feedstock: Feasibility study

Akkache

Hernández

Teixeira

et al. 2016

Biomass and Bioenergy

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International audienceGasification experiments were performed for several feedstocks alone (wastewater sludge, waste wood, reeds, olive pomace, solid recovered fuel, paper labels and plastic labels) using a fixed bed reactor operating in semi-batch conditions. In order to combine them in an optimal gasifying blend, the gasification behavior of each feedstock was compared with that of wastewater sludge through the following criteria: the raw feedstock proximate and ultimate composition, the solid conversion, the gas heating value, the pollutants release and the ashes melting. Operated alone, the conversion rate of the feedstocks after 58 min of solid residence time was over 77% of initial mass. The Syngas low heating value produced at 1123 K was in the range of 9.0 to 11.9 MJ m À3. The major concerns regarding the wastewater sludge were the pollutants precursors' release (NH 3 , COS…) and the ash slagging and fouling. The calculated slagging and fouling indexes were high also for olive pomace and for waste wood. Finally, among the possible blends studied the paper labels and plastic labels can be co-gasified with secondary and digested wastewater sludge without any restriction, reeds and solid recovered fuel can be blinded with secondary wastewater sludge without any restriction, a specific attention have to be taken to fouling when they are blended with digested wastewater sludge. The blend based on waste wood and olives pomace should be avoided for instance due to their ash slagging and fouling tendency

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Analysis of bed agglomeration during gasification of wheat straw in a bubbling fluidised bed gasifier using mullite as bed material

Cited by 30 publications

References 25 publications

Thermochemical equilibrium study of ash transformation during combustion and gasification of sewage sludge mixtures with agricultural residues with focus on the phosphorus speciation

Thermochemical equilibrium study of ash transformation during combustion and gasification of sewage sludge mixtures with agricultural residues with focus on the phosphorus speciation

Promoting effect of various biomass ashes on the steam gasification of low-rank coal

Co-gasification of wastewater sludge and different feedstock: Feasibility study

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