Ash and Flue Gas from Oil Shale Oxy-Fuel Circulating Fluidized Bed Combustion

Lauri Loo, Alar Konist, Dmitri Neshumayev, Tõnu Pihu, Birgit Maaten and Andres Siirde
Additional contact information
Lauri Loo: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
Alar Konist: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
Dmitri Neshumayev: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
Tõnu Pihu: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
Birgit Maaten: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia
Andres Siirde: Department of Energy Technology, Tallinn University of Technology, 19086 Tallinn, Estonia

Energies, 2018, vol. 11, issue 5, 1-12

Abstract: Carbon dioxide emissions are considered a major environmental threat. To enable power production from carbon-containing fuels, carbon capture is required. Oxy-fuel combustion technology facilitates carbon capture by increasing the carbon dioxide concentration in flue gas. This study reports the results of calcium rich oil shale combustion in a 60 kW th circulating fluidized bed (CFB) combustor. The focus was on the composition of the formed flue gas and ash during air and oxy-fuel combustion. The fuel was typical Estonian oil shale characterized by high volatile and ash contents. No additional bed material was used in the CFB; the formed ash was enough for the purpose. Two modes of oxy-fuel combustion were investigated and compared with combustion in air. When N 2 in the oxidizer was replaced with CO 2 , the CFB temperatures decreased by up to 100 °C. When oil shale was fired in the CFB with increased O 2 content in CO 2 , the temperatures in the furnace were similar to combustion in air. In air mode, the emissions of SO 2 and NO x were low (<14 and 141 mg/Nm 3 @ 6% O 2 , respectively). Pollutant concentrations in the flue gas during oxy-fuel operations remained low (for OXY30 SO 2 < 14 and NO x 130 mg/Nm 3 @ 6% O 2 and for OXY21 SO 2 23 and NO x 156 mg/Nm 3 @ 6% O 2 ). Analyses of the collected ash samples showed a decreased extent of carbonate minerals decomposition during both oxy-fuel experiments. This results in decreased carbon dioxide emissions. The outcomes show that oxy-fuel CFB combustion of the oil shale ensures sulfur binding and decreases CO 2 production.

Keywords: circulating fluidized bed combustion; carbon capture; storage and utilization; sulfur binding; nitrogen oxides; emissions; ash behavior; carbonate minerals (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2018
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://www.mdpi.com/1996-1073/11/5/1218/pdf (application/pdf)
https://www.mdpi.com/1996-1073/11/5/1218/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:11:y:2018:i:5:p:1218-:d:145581

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().