Bed Agglomeration Characteristics during Cocombustion of Animal Waste with Municipal Solid Waste in a Bubbling Fluidized-Bed Boiler—A Thermodynamic Modeling Approach

Moradian, Farzad; Pettersson, Anita; Richards, Tobias

doi:10.1021/ef402455h

Cited by 5 publications

(5 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermodynamic equilibrium modeling, coupled with experimental methods, has been used to achieve a better understanding of the ash transformation mechanisms during the combustion of biomass and waste-derived fuels. 7−12 In a previous study, 13 a thermodynamic equilibrium model was applied to assess the composition of the bottom ash in a commercial bubbling fluidized-bed (BFB) boiler, combusting a waste mixture of 20% MSW and 80% IW, referred herein as Solid Waste (SW). Data obtained from the full-scale tests were used as input for the equilibrium model, to evaluate the agglomeration tendency based on the different fuel composition, bed temperature, and air/fuel ratio.…”

Section: Introductionmentioning

confidence: 99%

“…In a previous study, a thermodynamic equilibrium model was applied to assess the composition of the bottom ash in a commercial bubbling fluidized-bed (BFB) boiler, combusting a waste mixture of 20% MSW and 80% IW, referred herein as Solid Waste (SW). Data obtained from the full-scale tests were used as input for the equilibrium model, to evaluate the agglomeration tendency based on the different fuel composition, bed temperature, and air/fuel ratio.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Thermodynamic Equilibrium Model Applied To Predict the Fouling Tendency in a Commercial Fluidized-Bed Boiler, Combusting Solid Waste

2015

Self Cite

View full text Add to dashboard Cite

A thermodynamic equilibrium model, combined with an advanced fuel analysis, was applied to predict the fouling tendency in a commercial bubbling fluidized-bed (BFB) boiler, combusting a mixture of solid waste. In order to enhance the performance of the model, further modifications were made, considering the combustion pattern in the fluidized-bed system and also the temperature profile in the combustion zone. The modeling was performed using Factsage, and experimental data obtained during the full-scale measurements were used as input for the model, simulating the deposit formation in the real boiler. The simulation results were then compared with the results obtained during the full-scale combustion tests to estimate the accuracy and validity of the applied model. The thermodynamic equilibrium modeling proved to be a reliable tool for predicting the fouling in the BFB boiler, thus determining the fraction of the melt in the deposited salts formed on the heat transfer surfaces during the flue gas condensation. The calculations showed that the ratio of the SO 2 to alkali chloride concentration in the flue gas was the decisive factor that affected the rate of the deposit formation in the boiler. Both the simulation and the experimental results indicated that lower bed temperatures and cocombustion of P-rich fuels decrease the deposition buildup in the boiler.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermodynamic Equilibrium Model Applied To Predict the Fouling Tendency in a Commercial Fluidized-Bed Boiler, Combusting Solid Waste

2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The fuel fingerprint allowed for quickly investigating how various fuel blends would affect the overall inorganic composition when deciding what blends that would be suitable. The approach with thermodynamical equilibrium calculations, which have been used previously for phosphorus-rich biomass, 16 proved a valuable tool for evaluating the fuel blends prior to actual experiments, and it worked well enough for the fuel system investigated here. The ash composition in this case, dominated by calcium, silicon, moderate amounts of phosphorus together with a very low alkali content, lends itself well to this type of slag modelling using current databases, which may not be the case for all types of fuel blends.…”

Section: Discussionmentioning

confidence: 99%

Fuel design in co-combustion of demolition wood chips and municipal sewage sludge

Skoglund

Bäfver²,

Fahlström³

et al. 2016

Fuel Processing Technology

View full text Add to dashboard Cite

PostprintThis is the accepted version of a paper published in Fuel processing technology. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Skoglund, N., Bäfver, L., Fahlström, J., Holmén, E., Renström, C. (2016) Fuel design in co-combustion of demolition wood chips and municipal sewage sludge Fuel processing technology, 141(2): 196-201 ABSTRACT: Municipal sewage sludge (MSS) is a waste stream resource which contains both energy and elements such as phosphorus which could be recycled. If these two aspects of this waste stream resource are to be used to their full potential the sludge should not be used in landfills or road construction. There is some use of sludge in agriculture today but not all MSS produced is suitable for direct use on arable land due to its content of potentially harmful elements, pathogens or anthropogenic chemicals. By combusting sludge that is not used directly in agriculture the problematic organic content could be destroyed. The combustion process also produces an ash that possibly could be used either directly in agriculture or as a raw material for recovering phosphorus and energy could be recovered. Building mono-combustion plants for sewage sludge is not economically feasible in all parts of the world so it is of interest to investigate how MSS can be introduced together with other fuels in existing infrastructure which already have extensive cleaning systems for potentially harmful elements.To investigate this possible path, demolition wood chips (DWC) were co-combusted with municipal sewage sludge (MSS) in a grate-fired combined heat and power plant running at 50% capacity producing 25 MW th and 9 MW el . The amount of MSS that was suitable to introduce in blends was determined using a "fuel fingerprint" based on the composition of the raw materials. Thermodynamic equilibrium calculations were made to evaluate potential problems with slagging based on the ash content prior to the combustion experiments. The fuels were introduced as a reference case with only demolition wood and pre-blended fuel mixtures in two ratios; 65 w/w-% DWC/35 w/w-% MSS and 55 w/w-% DWC/45 w/w-% MSS and were fired for 12 hours. The high water content of the MSS affected how much MSS that could be introduced without compromising the heat and power production.The fuel blends worked nicely for 12 hours of continuous combustion with small adjustments where the primarily the air inlet configuration was changed. The main problems encountered related to cleaning of the flue gases and to some extent ash removal. The bed ash and fly ash produced was analysed both using ICP-AES (elemental) and XRD (speciation) and the bottom ash was subjected to ash melting tests. The major nutrient phosphorus was mainly found in bottom ash (80 w/w-%) as whitlockites with some hydroxyapatite whereas fly ash (20 w/w-%) contained larger amounts of hydroxyapatite, especially for the reference fuel. The amou...

show abstract

“…The ash-induced problems have a significant impact on the operation of fluidized beds; hence, even qualitative predictions are essential. The proposed modeling approaches are usually based on equilibrium phase calculations for predicting what thermodynamically stable phases can form from reactions between the ash and bed material . The thermodynamic calculations can be further expanded by adding a diffusion model or even modeling the particle coating using discrete element models .…”

Section: Influence Of Fluidized Bed On Combustionmentioning

confidence: 99%

“…The proposed modeling approaches are usually based on equilibrium phase calculations for predicting what thermodynamically stable phases can form from reactions between the ash and bed material. 247 The thermodynamic calculations can be further expanded by adding a diffusion model 243 or even modeling the particle coating using discrete element models. 248 Alternatively, predictions can be based on empirical correlations.…”

Section: Influence Of Fluidized Bed On Combustionmentioning

confidence: 99%

Combustion of Biomass in Fluidized Beds: A Review of Key Phenomena and Future Perspectives

Kwong

Marek

2021

Energy Fuels

View full text Add to dashboard Cite

This review presents recent advances in research on fluidized bed combustion of solid biomass. While the main focus is on thermochemical processes occurring in fluidized beds, applicable investigations on biomass combustion from other research areas are also described as they often provide fundamental insight about the processing of biomass, applicable also in the context of fluidized beds. This review aims to summarize lessons learned and indicate some remaining gaps in the existing body of knowledge. The review discusses combustion in separate stages, such as drying, pyrolysis, and homo-and heterogeneous combustion, and characterizes how fluidized beds affect combustion, discussing heat and mass transfer, material segregation, and bed agglomeration. Finally, advances in new research trends and the prospects for technology development are considered, highlighting the chemical-looping technology with its inherent potential for carbon capture, scale-up of advanced computational models, and progress in spectroscopic and tomographic studies applied to combustion.

show abstract

Bed Agglomeration Characteristics during Cocombustion of Animal Waste with Municipal Solid Waste in a Bubbling Fluidized-Bed Boiler—A Thermodynamic Modeling Approach

Cited by 5 publications

References 27 publications

Thermodynamic Equilibrium Model Applied To Predict the Fouling Tendency in a Commercial Fluidized-Bed Boiler, Combusting Solid Waste

Thermodynamic Equilibrium Model Applied To Predict the Fouling Tendency in a Commercial Fluidized-Bed Boiler, Combusting Solid Waste

Fuel design in co-combustion of demolition wood chips and municipal sewage sludge

Combustion of Biomass in Fluidized Beds: A Review of Key Phenomena and Future Perspectives

Contact Info

Product

Resources

About