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Zhou, C., Rosén, C. & Engvall, K. (2017). Selection of dolomite bed material for pressurized biomass gasification in BFB. Fuel processing technology, 159, 460-473
Open this publication in new window or tab >>Selection of dolomite bed material for pressurized biomass gasification in BFB
2017 (English)In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 159, p. 460-473Article in journal (Refereed) Published
Abstract [en]

Dolomite is considered advantageous as bed material in fluidized bed gasification processes, due to its catalytic tar cracking and anti-sintering properties. However, in case of pressurized fluidized bed gasifiers, the use of dolomite is challenging. High temperature in the presence of steam favors the production of clean syngas due to the intensified cracking of tar in the presence of CaO, whereas it simultaneously increases the tendency of fragmentation of dolomite particles after full calcination. The present study was carried out to examine the influence of the properties of dolomite on the stability of dolomite in a pressurized fluidized bed gasifier, with the aim of determining criteria for dolomite selection. Glanshammar dolomite exhibited a better stability in the mechanital strength after calcination, compared to Sala dolomite. The corresponding change of micro-structure that occurred during dolomite chemical transformation was presented. The crystal pattern and Si distribution in the crystal lattice are the possible explanations for the superior performance of the Glanshammar dolomite compared to the Sala dolomite.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2017
Keywords
Dolomite, Pores, Crystal, Pressurized fluidized bed, Gasification
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-206238 (URN)10.1016/j.fuproc.2017.01.008 (DOI)000397353800050 ()2-s2.0-85012025848 (Scopus ID)
Note

QC 20170517

Available from: 2017-05-17 Created: 2017-05-17 Last updated: 2017-05-19Bibliographically approved
Zhou, C. (2014). Gasification and Pyrolysis Characterization and Heat Transfer Phenomena During Thermal Conversion of Municipal Solid Waste. (Doctoral dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Gasification and Pyrolysis Characterization and Heat Transfer Phenomena During Thermal Conversion of Municipal Solid Waste
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The significant generation of municipal solid waste (MSW) has become a controversial global issue. Pyrolysis and gasification technologies for treating rejects from solid waste disposal sites (SWDSs), for which over 50 % of MSW is attributed to combustible species, have attracted considerable attention. MSW is an alternative energy source that can partly replace fossil resources; there is an increasing awareness that global warming caused by the utilization of fossil resources is occurring.

The goal of this thesis is to realize the efficient and rational utilization of MSW and decrease the harmful impact of pollutants, such as dioxin, HCl, and CO2, on the environment. To achieve this goal, some fundamental studies have been experimentally and numerically conducted to enhance the understanding of the properties of municipal solid waste thermal conversion.

In this thesis, the pyrolysis behaviors of single pelletized recovered fuel were tested. A detailed comparison of the pyrolysis behaviors of typical recovered solid waste and biomass particles was conducted. A swelling phenomenon with a swelling ratio of approximately 1.6 was observed on the surface of pelletized recovered fuels. Subsequently, a particle model was constructed to describe the thermal conversion process for large recovered fuel particles that are composed of a high fraction of polyethylene (PE) and a comparable low fraction of cardboard. The results indicate that an understanding of the heat transfer mechanism in highly porous and molten structures and the selection of a heat transfer model are crucial for accurate prediction of the conversion process.

MSW pyrolysis is a promising method for producing liquid products. With the exception of lignocellulosic materials, such as printing paper and cardboard, PE, polystyrene (PS), polypropylene (PP), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) are the six main polymers in domestic waste in Europe. Characterization studies of the products obtained from these individual components, such as PE, PET, PVC, printing paper, and cardboard, have been conducted on a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) system and a fixed-bed reactor. The possible pathways for the formation of the main primary/secondary products in rapid and conventional pyrolysis were also discussed.

MSW steam gasification with CaO was performed in a batch-type fixed-bed gasifier to examine the effect of CaO addition on the heat transfer properties, pollutant removal, and devolatilization and char gasification behaviors in the presence of steam.

A new carbon capture and recycle (CCR) system combined with an integrated municipal solid waste system was proposed. The foundation of the system is the development of a novel method to remediate CO2 using a high-temperature process of reforming CH4 and/or O2 and/or H2O without catalysts. Thermodynamic and experimental studies were performed. High temperatures significantly promoted the multi-reforming process while preventing the problem of catalyst deactivation. Potential improvements in the efficiency of the novel technology can be achieved by optimizing the reforming reactants. Landfill gas (LFG) and fuel gas from bio-waste treatment contain a considerable fraction of CH4, which may be a source of CH4 for this process.  

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. p. xiv, 127
Keywords
municipal solid waste, pyrolysis, gasification, heat transfer, CaO, CO2, reforming, numerical model
National Category
Energy Engineering
Research subject
Energy Technology; Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-154587 (URN)978-91-7595-284-0 (ISBN)
Public defence
2014-11-10, Sal F3, Lindstedtvägen 26, KTH, stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC20141028

Available from: 2014-10-28 Created: 2014-10-24 Last updated: 2014-10-28Bibliographically approved
Zhou, C. & Yang, W. Effect of heat transfer model on the prediction of municipal solid waste (MSW) pyrolysis process.
Open this publication in new window or tab >>Effect of heat transfer model on the prediction of municipal solid waste (MSW) pyrolysis process
(English)Manuscript (preprint) (Other academic)
Keywords
municipal solid waste (MSW), pyrolysis, heat transfer model, polyethylene;
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-154870 (URN)
Note

QS 2014

Available from: 2014-10-28 Created: 2014-10-28 Last updated: 2014-10-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9760-9298

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