Biological Nitrogen Removal of Effluents from Amine-based CO2 Capture Plants: Screening, Feasibility and Limitations
Abstract
Biological Treatment of Waste from Carbon Capture and Storage (CCS) – Screening, feasibility and limitations.
Carbon capture and storage (CCS) is becoming an important technology to combat climate change. In CCS, carbon dioxide (CO2) from power plants and industry is captured, compressed and stored in underground formations. CO2 can be captured by absorption to different chemicals, such as nitrogen (N)-containing amines. During the process, the solvent is reclaimed for reuse, but it will gradually be degraded due to side-reactions and heating. This by-product has to be removed as waste. As economic and efficient waste disposal systems are not yet established, this thesis focuses on how to do so.
The process waste contains mainly undegraded amine as well as other nitrogen compounds. Most of those can be biodegraded, in a process called biological nitrogen removal (BNR). This is a two-step process called nitrification and denitrification, eventually resulting in non-toxic dinitrogen (N2) gas, as found at 78% in the air. The nitrifying bacteria are more sensitive and require oxygen, while the denitrifying bacteria work under so called anoxic conditions utilizing nitrate for their respiration. For screening purposes, the biodegradability of different amines was measured with and without oxygen and results revealed big differences. For assessing the anoxic biodegradability, a new rapid and simple method was developed, applying syringes filled with biofilm carriers. Monoethanolamine (MEA), the most common amine at use so far, and its reclaimer waste were successfully treated over a long-term period in the complete BNR process described above. These feasibility studies were done in moving bed biofilm reactors (MBBRs). While the organic matter could be utilized by the denitrifiers, the nitrifying bacteria were inhibited at the same concentrations. Furthermore, loading and biofilm composition were identified as important limitation factors of the process.
In total, this work shows that amine-based CCS waste can successfully be treated biologically with BNR processes as outlined.
Has parts
Paper 1: Hauser, Ingrid; Einbu, Aslak; Svendsen, Hallvard Fjøsne; Østgaard, Kjetill. Biological treatment of effluents generated by amine based CO2-capture plants. Journal of Energy Challenges and Mechanics 2014 ;Volum 1.(4) s. http://creativecommons.org/licenses/by/3.0/Paper 2: Østgaard, K., Shuai, W., Henry, I. A., Sposob, M., Kowarz, V., Haugen, H. H. & Bakke, R. 2016. Syringe test screening of microbial gas production activity: Cases denitrification and biogas formation. Journal of Microbiological Methods, Volume 132, January 2017, Pages 119–124 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ the final version is available at http://dx.doi.org/10.1016/j.mimet.2016.11.021
Paper 3: Henry, I. A., Kowarz, V. & Østgaard, K. 2016. Aerobic and anoxic biodegradability of amines applied in CO2-capture. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Paper 4: Hauser, Ingrid; Einbu, Aslak; Østgaard, Kjetill; Borges Colaco, Ana; Skjæran, Julie Anita; Svendsen, Hallvard Fjøsne; Cervantes, Francisco Javier. Biological N Removal from Wastes Generated from Amine-Based CO2 Capture: Case Monoethanolamine. Applied Biochemistry and Biotechnology 2013 ;Volum 169.(4) s. 1449-1458, Is not included due to copyright available at http://dx.doi.org/10.1007/s12010-012-0075-0
Paper 5: Hauser, Ingrid; Einbu, Aslak; Østgaard, Kjetill; Svendsen, Hallvard Fjøsne; Cervantes, Francisco Javier. Biodegradation of amine waste generated from post-combustion CO2 capture in a moving bed biofilm treatment system. Biotechnology letters 2013 ;Volum 35.(2) s. 219-224 Is not included due to copyright available at http://dx.doi.org/10.1007/s10529-012-1073-6
Paper 6: Henry, Ingrid Annemarie; Einbu, Aslak; Svendsen, Hallvard Fjøsne; Bakke, Ingrid; Østgaard, Kjetill. Inhibition factors in biofilm N removal systems treating wastes generated by amine based CO2 capture. International Journal of Greenhouse Gas Control 2016 ;Volum 45. s. 200-206 http://dx.doi.org/10.1016/j.ijggc.2015.12.023 The article in is reprinted with kind permission from Elsevier, sciencedirect.com