Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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
Bioprocessing of Recalcitrant Substrates for Biogas Production
University of Borås, Faculty of Textiles, Engineering and Business.
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Sustainable development
The publication has "Sustainable Development" as a keyword
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 [en]
anaerobic digestion, biogas, lignocellulose, wool, keratin, pre-treatment, co-digestion, dry digestion, economic evaluation
National Category
Environmental Biotechnology
Research subject
Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-597ISBN: 978-91-87525-69-8 (print)ISBN: 978-91-87525-70-4 (print)OAI: oai:DiVA.org:hb-597DiVA: diva2:844933
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
List of papers
1. Effect of the N-methylmorpholine-N-oxide (NMMO) pretreatment on anaerobic digestion of forest residues
Open this publication in new window or tab >>Effect of the N-methylmorpholine-N-oxide (NMMO) pretreatment on anaerobic digestion of forest residues
2013 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 8, no 4, 5409-5423 p.Article in journal (Refereed) Published
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
Keyword
Forest residues, NMMO, anaerobic digestion, inhibition, biogas, lignocelluloses, degradation, Biofuel
National Category
Industrial Biotechnology Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1627 (URN)000328280700050 ()2320/12723 (Local ID)2320/12723 (Archive number)2320/12723 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-01Bibliographically approved
2. Enhanced methane production from wool textile residues by thermal and enzymatic pretreatment
Open this publication in new window or tab >>Enhanced methane production from wool textile residues by thermal and enzymatic pretreatment
2013 (English)In: Process Biochemistry, ISSN 1359-5113, E-ISSN 1873-3298, Vol. 48, no 4, 575-580 p.Article in journal (Refereed) Published
Abstract [en]

Methane production from two types of wool textile wastes (TW1 and TW2) was investigated. To improve the digestibility of these textiles, different pretreatments were applied, and comprised thermal treatment (at 120 ◦C for 10 min), enzymatic hydrolysis (using an alkaline endopeptidase at different levels of enzymatic loading, at 55 ◦C for 0, 2, and 8 h), and a combination of these two treatments. Soluble protein concentration and sCOD (soluble chemical oxygen demand) were measured to evaluate the effectivity of the different pretreatment conditions to degrade wool keratin. The sCOD as well as the soluble protein content had increased in both textile samples in comparison to untreated samples, as a response to the different pretreatments indicating breakdown of the wool keratin structure. The combined treatments and the thermal treatments were further evaluated by anaerobic batch digestion assays at 55 ◦C. Combined thermal and enzymatic treatment of TW1 and TW2 resulted in methane productions of 0.43 N m3/kg VS and 0.27 N m3/kg VS, i.e., 20 and 10 times higher yields, respectively, than that gained from untreated samples. The application of thermal treatment by itself was less effective and resulted in increasing the methane production by 10-fold for TW1 and showing no significant improvement for TW2.

Place, publisher, year, edition, pages
Elsevier, 2013
Keyword
Anaerobic digestion, Wool textile, Keratin, Pretreatment, Enzyme, Chemical Enginering
National Category
Chemical Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1616 (URN)10.1016/j.procbio.2013.02.029 (DOI)000320413900004 ()2320/12679 (Local ID)2320/12679 (Archive number)2320/12679 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-01Bibliographically approved
3.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.
4. Dry anaerobic digestion of lignocellulosic and protein residues
Open this publication in new window or tab >>Dry anaerobic digestion of lignocellulosic and protein residues
2015 (English)In: Biofuel Research Journal, Vol. 2, no 4, 309-316 p.Article in journal (Refereed) Published
Abstract [en]

Utilisation of wheat straw and wool textile waste in dry anaerobic digestion (AD) process was investigated. Dry-AD of the individual substrates as well as co-digestion of those were evaluated using different total solid (TS) contents ranging between 6 to 30%. Additionally, the effects of the addition of nutrients and cellulose- or protein-degrading enzymes on the performance of the AD process were also investigated. Dry-AD of the wheat straw resulted in methane yields of 0.081 – 0.200 Nm3CH4/kgVS with the lowest and highest values obtained at 30 and 21% TS, respectively. The addition of the cellulolytic enzymes could significantly increase the yield in the reactor containing 13% TS (0.231 Nm3CH4/kg VS). Likewise, degradation of wool textile waste was enhanced significantly at TS of 13% with the addition of the protein-degrading enzyme (0.131 Nm3CH4/kg VS). Furthermore, the co-digestion of these two substrates showed higher methane yields compared with the methane potentials calculated for the individual fractions at all the investigated TS contents due to synergetic effects and better nutritional balance.

National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-3742 (URN)10.18331/BRJ2015.2.4.5 (DOI)
Available from: 2015-12-06 Created: 2015-12-06 Last updated: 2016-02-15Bibliographically approved
5. Biogas production from lignocelluloses by N-methylmorpholine-N-oxide (NMMO) pretreatment: Effects of recovery and reuse of NMMO
Open this publication in new window or tab >>Biogas production from lignocelluloses by N-methylmorpholine-N-oxide (NMMO) pretreatment: Effects of recovery and reuse of NMMO
2014 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 161, 446-450 p.Article in journal (Refereed) Published
Abstract [en]

The effects of N-methylmorpholine-N-oxide (NMMO) pretreatment on barley straw and forest residues were investigated for biogas production. The pretreatments were performed at 90 °C with 85% NMMO for 3–30 h. The best pretreatment conditions resulted in 100% improvement in methane yield during the subsequent digestion compared to that of the untreated lignocelluloses. Methane yields of 0.23 and 0.15 Nm3 CH4/kg VS were obtained from barley straw and forest residues, respectively, corresponding to 88% and 83% of the theoretical yields. In addition, the effects of the pretreatment with recovered and reused NMMO was also studied over the course of five cycles. Pretreatment with recycled NMMO showed the same performance as the fresh NMMO on barley straw. However, pretreatment of forest residues with recycled NMMO resulted in 55% reduction in methane yield.

Place, publisher, year, edition, pages
Elsevier, 2014
Keyword
Resource Recovery
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1888 (URN)10.1016/j.biortech.2014.03.107 (DOI)000335436000058 ()24736089 (PubMedID)2320/14030 (Local ID)2320/14030 (Archive number)2320/14030 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-01Bibliographically approved
6. Experimental and economical evaluation of bioconversion of forest residues to biogas using organosolv pretreatment
Open this publication in new window or tab >>Experimental and economical evaluation of bioconversion of forest residues to biogas using organosolv pretreatment
2015 (English)In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 178, 201-8 p.Article in journal (Refereed) Published
Abstract [en]

The methane potential of forest residues was compared after applying organic solvent, i.e., acetic acid, ethanol, and methanol pretreatments using batch anaerobic digestion (AD). The pretreatments were performed at 190 °C with 50% (V/V) organic solvent for 60 min. The accumulated methane yields after 40 days of AD from pretreated forest residues were between 0.23 and 0.34 m3 CH4/kg VS, which shows a significant improvement compared to 0.05 m3 CH4/kg VS, from untreated forest residues. These improvements count up to 50% increase in the methane yields from the pretreated substrates based on expected theoretical yield from carbohydrates. Among the organic solvents, pretreatments with acetic acid and ethanol led to highest methane yields, i.e., over 0.30 m3 CH4/kg VS. However, techno-economical evaluation showed, pretreatment with methanol was more viable financially. The capital investments of the plant operating 20,000 tons of forest residues varied between 56 and 60 million USD, which could be recovered in less than 8 years of operation.

Place, publisher, year, edition, pages
Elsevier, 2015
Keyword
anaerobic digestion, lignocelluloses, organosolv, pretreatments, process design
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1894 (URN)10.1016/j.biortech.2014.07.064 (DOI)25113881 (PubMedID)2320/14037 (Local ID)2320/14037 (Archive number)2320/14037 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-12-01Bibliographically approved

Open Access in DiVA

omslag(1261 kB)75 downloads
File information
File name COVER01.pdfFile size 1261 kBChecksum SHA-512
6b9889e8587e741caad92632b483cf3560b7a98f011e28377a1b67dcc32146034a2dbed8e022a608bba0bf4a56b041e20e0e352067351a746c1ddf27af74055e
Type coverMimetype application/pdf
spikblad(41 kB)77 downloads
File information
File name SPIKBLAD01.pdfFile size 41 kBChecksum SHA-512
22f430bee9f704aa8d3979aed20026c0509c629f24dc66aebb027827c8b2153f22565bb25b60ce13942f6bdc73f8092cba90da468ba94f574350938a6e1dfebb
Type spikbladMimetype application/pdf
fulltext(4165 kB)762 downloads
File information
File name FULLTEXT01.pdfFile size 4165 kBChecksum SHA-512
5433ed7630d6478300097f500a0f5f121c617d564cff5517438bc6f9172fd591c9f984da4bde5d03bc069af1ccba015e1901941c592606a44a6cb796130fb35c
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Kabir, Maryam M
By organisation
Faculty of Textiles, Engineering and Business
Environmental Biotechnology

Search outside of DiVA

GoogleGoogle Scholar
Total: 762 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1727 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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