Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effect of the N-methylmorpholine-N-oxide (NMMO) pretreatment on anaerobic digestion of forest residues
University of Borås, School of Engineering.
University of Borås, School of Engineering.ORCID iD: 0000-0003-4887-2433
University of Borås, School of Engineering.
2013 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 8, no 4, 5409-5423 p.Article in journal (Refereed) Published
Sustainable development
The content falls within the scope of Sustainable Development
Abstract [en]

Pretreatment of forest residues using N - methylmorpholine - N - oxide (NMMO or NMO) prior to anaer obic digestion was investigated , where the effects of particle size, NMMO concentration , and pretreatment time were the primary focus. The pretreatments were carried out on forest residues; with different particle size s of 2, 4 and 8 mm , at 120 °C for 3, 7 , and 15 h in two different modes of NMMO - treatment : dissolution by 85% NMMO and swelling without dissolution using 75% NMMO solution in water . The pretreatment process led to minor changes in the composition of the forest residues . The best improvement in methane yield of the forest residues was achieved by pretreatment using 85% NMMO for 15 h at 120 °C. This treatment resulted in 0.1 7 Nm 3 /kg VS methane yield , which corresponds to 83 % of the expected theoretical yield of carbohydrates present in the material. Additionally, the accumulated methane yield and the rate of the methane production were highly affected by the amounts of remaining NMMO when it was not well separated during the washing and filtration step s after the treatment. The p resence o f concentrations even as low as 0.008 % NMMO resulted in a decrease in the final methan e yield by 45% , while the presence of 1% of this solvent in the digester completely terminated the anaerobic digestion process.

Place, publisher, year, edition, pages
North Carolina State University: College of Natural Resources , 2013. Vol. 8, no 4, 5409-5423 p.
Keyword [en]
Forest residues, NMMO, anaerobic digestion, inhibition, biogas, lignocelluloses, degradation, Biofuel
National Category
Industrial Biotechnology Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-1627ISI: 000328280700050Local ID: 2320/12723OAI: oai:DiVA.org:hb-1627DiVA: diva2:869696
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2016-07-13Bibliographically approved
In thesis
1. Bioprocessing of Recalcitrant Substrates for Biogas Production
Open this publication in new window or tab >>Bioprocessing of Recalcitrant Substrates for Biogas Production
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The application of anaerobic digestion (AD) as a sustainable waste management technology is growing worldwide, due to high energy prices as well as increasingly strict environmental regulations. The growth of the AD industry necessitates exploring new substrates for their utilisation in AD processes. The present work investigates the AD of two recalcitrant biomass: lignocelluloses and keratin-rich residues. The complex nature of these waste streams limits their biological degradation; therefore, suitable pre-processing is required prior to the AD process.In the first part of the study, the effects of organic solvent pre-treatments on bioconversion of lignocelluloses (straw and forest residues) to biogas were evaluated. Pre-treatment with N-methylmorpholine-N-oxide (NMMO) resulted in minor changes in the composition of the substrates, while their digestibility significantly increased. Furthermore, due to the high cost of the NNMO, the effect of pre-treatment with the recycled solvent was also explored. Since it was found that the presence of small traces of NMMO in the system after the treatment has inhibitory effects on AD, pre-treatments of forest residues using other organic solvents, i.e. acetic acid, ethanol, and methanol, were investigated too. Although pre-treatments with acetic acid and ethanol led to the highest methane yields, the techno-economical evaluation of the process showed that pre-treatment with methanol was the most viable economically, primarily due to the lower cost of methanol, compared to that of the other solvents.In the second part of the work, wool textile wastes were subjected to biogas production. Wool is mainly composed of keratin, an extremely strong and resistible structural protein. Thermal, enzymatic and combined treatments were, therefore, performed to enhance the methane yield. The soluble protein content of the pre-treated samples showed that combined thermal and enzymatic treatments had significantly positive effects on wool degradation, resulting in the highest methane yields, i.e. 10–20-fold higher methane production, compared to that obtained from the untreated samples.In the last part of this thesis work, dry digestion of wheat straw and wool textile waste, as well as their co-digestion were studied. The total solid (TS) contents applied in the digesters were between 6–30% during the investigations. The volumetric methane productivity was significantly enhanced when the TS was increased from 6 to 13–21%. This can be a beneficial factor when considering the economic feasibility of large-scale dry AD processes.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2015. 65 p.
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 70
Keyword
anaerobic digestion, biogas, lignocellulose, wool, keratin, pre-treatment, co-digestion, dry digestion, economic evaluation
National Category
Environmental Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-597 (URN)978-91-87525-69-8 (ISBN)978-91-87525-70-4 (ISBN)
Public defence
2015-10-09, D207, Allégatan 1, Borås, Sweden., Borås, 10:00 (English)
Available from: 2015-09-04 Created: 2015-08-10 Last updated: 2016-01-13Bibliographically approved

Open Access in DiVA

No full text

Other links

http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_08_4_5409_Kabir_NMMO_Anaerobic_Digestion/2340

Search in DiVA

By author/editor
Kabir, Maryam MTaherzadeh, Mohammad. J.Sárvári Horváth, Ilona
By organisation
School of Engineering
In the same journal
BioResources
Industrial BiotechnologyIndustrial Biotechnology

Search outside of DiVA

GoogleGoogle Scholar

Total: 155 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf