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Ylitervo, Päivi
Alternative names
Publications (10 of 27) Show all publications
Mohammadkhani, G., Mahboubi, A., Plöhn, M., Funk, C. & Ylitervo, P. (2024). The potential of Nordic microalgae in nutrient removal from anaerobic digestion effluents. Physiologia Plantarum, 176(1)
Open this publication in new window or tab >>The potential of Nordic microalgae in nutrient removal from anaerobic digestion effluents
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2024 (English)In: Physiologia Plantarum, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 176, no 1Article in journal (Refereed) Published
Abstract [en]

Anaerobic digestion is a promising method for organic waste treatment. While the obtained digestate can function as fertilizer, the liquid fraction produced is rather problematic to discharge due to its high nitrogen and chemical oxygen demand contents. Microalgae have great potential in sustainable nutrient removal from wastewater. This study aimed at evaluating native Swedish microalgae cultivation (batch operation mode, 25°C and continuous light of 80 μmol m−2 s−1) on anaerobic digestion effluent of pulp and paper sludge (PPS) or chicken manure (CKM) to remove ammonium and volatile fatty acids (VFAs). While algal strains, Chlorella vulgaris, Chlorococcum sp., Coelastrella sp., Scotiellopsis reticulata and Desmodesmus sp., could assimilate VFAs as carbon source, acetic acid was the most preferred. Higher algal biomass and cell densities were achieved using PPS compared to CKM. In PPS, Coelastrella sp. and Chlorella vulgaris reached the highest cell densities after 15 days, about 79 × 106 and 43 × 106 cells mL−1, respectively. Although in PPS, ammonium was completely assimilated (195 mg L−1), this was only 46% (172 mg L−1) in CKM. Coelastrella sp. produced the highest biomass concentration independently of the medium (1.84 g L−1 in PPS and 1.99 g L−1 in CKM). This strain is a promising candidate for nutrient removal and biomass production in the aforementioned media, followed by Chlorella vulgaris and Chlorococcum sp. They have great potential to reduce the environmental impact of industrial anaerobic digestion effluents in Nordic countries.

National Category
Other Industrial Biotechnology
Research subject
Resource Recovery; Resource Recovery
Identifiers
urn:nbn:se:hb:diva-31282 (URN)10.1111/ppl.14153 (DOI)001134340600001 ()2-s2.0-85181494300 (Scopus ID)
Funder
Swedish Research Council Formas, 2019‐00492
Note

The authors are thankful to ÅForsk (22-228) for the financial support of this project. The authors also are grateful to the Swedish Research Council FORMAS (2019-00492) to CF, Bio4Energy (www.bio4energy.se) to CF and Umeå University for their financial support.

Available from: 2024-01-11 Created: 2024-01-11 Last updated: 2024-02-01Bibliographically approved
Yangin-Gomec, C., Agnihotri, S., Ylitervo, P. & Sárvári Horváth, I. (2023). Assessment of Microbial Diversity during Thermophilic Anaerobic Co-Digestion for an Effective Valorization of Food Waste and Wheat Straw. Energies, 16(1), Article ID 15.
Open this publication in new window or tab >>Assessment of Microbial Diversity during Thermophilic Anaerobic Co-Digestion for an Effective Valorization of Food Waste and Wheat Straw
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 1, article id 15Article in journal (Refereed) Published
Abstract [en]

In this study, predominant bacterial and archaeal populations and their roles during anaerobic mono-digestion of food waste (FW) and co-digestion of FW with straw pellets (SP) at thermophilic temperature (53 ± 1 °C) were assessed by Next Generation Sequencing (NGS) analysis at organic loading rates (OLRs) of 3.0 and 7.0 gVS/L/d. Depending on the seed; results revealed that Firmicutes, Bacteroidetes, and Proteobacteria were, respectively the most prevalent bacterial phyla at both OLRs investigated. On the other hand, Euryarchaeota was dominated by methanogens playing crucial role in biogas production and correlated mainly with the activities of Methanobacteria and Methanomicrobia at class level. Acetoclastic Methanosaetae was the predominant genus at OLR = 3.0 gVS/L/d; however, shared the same predominance with hydrogenotrophic methanogens Methanospirillium at the highest OLR. Although no clear effect in response to straw addition at OLR of 3.0 gVS/L/d could be seen in terms of methanogenic archaea at genus level, hydrogenotrophic methanogens revealed some shift from Methanobacterium to Methanospirillium at higher OLR. Nevertheless, no prominent microbial shift in the presence of wheat straw at increased OLR was likely due to adapted inoculation at start-up which was also demonstrated by relatively stable biogas yields during co-digestion.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
biogas yield, co-substrate, food waste, methanogens, next generation sequencing
National Category
Other Industrial Biotechnology
Identifiers
urn:nbn:se:hb:diva-29248 (URN)10.3390/en16010055 (DOI)000909041900001 ()2-s2.0-85145776617 (Scopus ID)
Available from: 2023-01-11 Created: 2023-01-11 Last updated: 2024-01-16
Usino, D., Sar, T., Ylitervo, P. & Richards, T. (2023). Effect of Acid Pretreatment on the Primary Products of Biomass Fast Pyrolysis. Energies, 16(5), Article ID 2377.
Open this publication in new window or tab >>Effect of Acid Pretreatment on the Primary Products of Biomass Fast Pyrolysis
2023 (English)In: Energies, E-ISSN 1996-1073, Vol. 16, no 5, article id 2377Article in journal (Refereed) Published
Abstract [en]

A high load of inorganics in raw lignocellulosic biomass is known to inhibit the yield of bio-oil and alter the chemical reactions during fast pyrolysis of biomass. In this study, palm kernel shell (PKS), an agricultural residue from palm oil production, and two other woody biomass samples (mahogany (MAH) sawdust and iroko (IRO) sawdust) were pretreated with distilled water or an acidic solution (either acetic, formic, hydrochloric (HCl) or sulfuric acid (H2SO4)) before fast pyrolysis in order to investigate its effect on the primary products and pyrolysis reaction pathways. The raw and pretreated PKS, MAH and IRO were pyrolysed at 600 °C and 5 s with a micro-pyrolyser connected to a gas chromatograph–mass spectrometer/flame ionisation detector (GC-MS/FID). Of the leaching solutions, HCl was the most effective in removing inorganics from the biomass and enhancing the primary pyrolysis product formed compared to the organic acids (acetic and formic acid). The production of levoglucosan was greatly improved for all pretreated biomasses when compared to the original biomass but especially after HCl pretreatment. Additionally, the relative content of the saccharides was maximised after pretreatment with H2SO4, which was due to the increased production of levoglucosenone. The relative content of the saccharides increased by over 70%. This increase may have occurred due to a possible reaction catalysed by the remaining acid in the biomass. The production of furans, especially furfural, was increased for all pretreatments but most noticeable when H2SO4 was used. However, the relative content of acids and ketones was generally reduced for PKS, MAH and IRO across all leaching solutions. The relative content of the phenol-type compound decreased to a large extent during pyrolysis after acid pretreatment, which may be attributed to dehydration and demethoxylation reactions. This study shows that the production of valuable chemicals could be promoted by pretreatment with different acid solutions.

Keywords
fast pyrolysis, primary products, pretreatment of biomass, Py-GC/MS/FID
National Category
Other Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-29503 (URN)10.3390/en16052377 (DOI)000947431700001 ()2-s2.0-85149769711 (Scopus ID)
Available from: 2023-03-03 Created: 2023-03-03 Last updated: 2024-02-01Bibliographically approved
Usino, D., Ylitervo, P. & Richards, T. (2023). Primary Products from Fast Co-Pyrolysis of Palm Kernel Shell and Sawdust. Molecules, 28(19), Article ID 6809.
Open this publication in new window or tab >>Primary Products from Fast Co-Pyrolysis of Palm Kernel Shell and Sawdust
2023 (English)In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 28, no 19, article id 6809Article in journal (Refereed) Published
Abstract [en]

Co-pyrolysis is one possible method to handle different biomass leftovers. The success of the implementation depends on several factors, of which the quality of the produced bio-oil is of the highest importance, together with the throughput and constraints of the feedstock. In this study, the fast co-pyrolysis of palm kernel shell (PKS) and woody biomass was conducted in a micro-pyrolyser connected to a Gas Chromatograph–Mass Spectrometer/Flame Ionisation Detector (GC–MS/FID) at 600 °C and 5 s. Different blend ratios were studied to reveal interactions on the primary products formed from the co-pyrolysis, specifically PKS and two woody biomasses. A comparison of the experimental and predicted yields showed that the co-pyrolysis of the binary blends in equal proportions, PKS with mahogany (MAH) or iroko (IRO) sawdust, resulted in a decrease in the relative yield of the phenols by 19%, while HAA was promoted by 43% for the PKS:IRO-1:1 pyrolysis blend, and the saccharides were strongly inhibited for the PKS:MAH-1:1 pyrolysis blend. However, no difference was observed in the yields for the different groups of compounds when the two woody biomasses (MAH:IRO-1:1) were co-pyrolysed. In contrast to the binary blend, the pyrolysis of the ternary blends showed that the yield of the saccharides was promoted to a large extent, while the acids were inhibited for the PKS:MAH:IRO-1:1:1 pyrolysis blend. However, the relative yield of the saccharides was inhibited to a large extent for the PKS:MAH:IRO-1:2:2 pyrolysis blend, while no major difference was observed in the yields across the different groups of compounds when PKS and the woody biomass were blended in equal amounts and pyrolysed (PKS:MAH:IRO-2:1:1). This study showed evidence of a synergistic interaction when co-pyrolysing different biomasses. It also shows that it is possible to enhance the production of a valuable group of compounds with the right biomass composition and blend ratio. 

Keywords
biomass blend, co-pyrolysis, fast pyrolysis, primary products, Py-GC-MS/FID
National Category
Energy Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-30679 (URN)10.3390/molecules28196809 (DOI)001084042800001 ()2-s2.0-85173900347 (Scopus ID)
Available from: 2023-10-23 Created: 2023-10-23 Last updated: 2023-11-15Bibliographically approved
Supriyanto, S., Ylitervo, P. & Richards, T. (2021). Gaseous products from primary reactions of fast plastic pyrolysis. Journal of Analytical and Applied Pyrolysis, 158
Open this publication in new window or tab >>Gaseous products from primary reactions of fast plastic pyrolysis
2021 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 158Article in journal (Refereed) Published
Abstract [en]

This study aimed to establish primary reactions and identify gaseous products during fast pyrolysis of low-density polyethylene (LDPE), polypropylene (PP) and polystyrene (PS). Fast pyrolysis was performed by using Py-GC/MS/FID at 574 ± 22 °C for 5 s. Gaseous fractions formed during pyrolysis of LDPE, PP and PS were 14 ± 1 wt%, 31 ± 3 wt% and 103 ± 12 wt%, respectively. The main gaseous compounds from LDPE were butane, 1-pentane and 1-hexene. PP pyrolysis gave propene, pentane and 2,4-dimethyl-1-heptene as the main gaseous compounds. Styrene monomer was the dominant gas from PS. The results showed that polyolefin (PP and PE) produced aliphatic hydrocarbons, while PS formed aromatic hydrocarbons. Furthermore, the proposed mechanism suggests that both inter- and intra-molecular hydrogen transfer occur during PP and PE pyrolysis. PS pyrolysis involves a C-C cleavage at the aliphatic side chain. This work is important to understand the mechanism of gas formation of primary reactions from pyrolysis of common plastics.

Keywords
Fast pyrolysis, Gas products, Primary reactions, Polyethylene, Polypropylene, Polystyrene
National Category
Energy Engineering
Identifiers
urn:nbn:se:hb:diva-26037 (URN)10.1016/j.jaap.2021.105248 (DOI)000687223400008 ()2-s2.0-85109107107 (Scopus ID)
Available from: 2021-07-10 Created: 2021-07-10 Last updated: 2021-09-07Bibliographically approved
Usino, D., Ylitervo, P., Moreno, A., Sipponen, M. H. & Richards, T. (2021). Primary interactions of biomass components during fast pyrolysis. Journal of Analytical and Applied Pyrolysis, 159, Article ID 105297.
Open this publication in new window or tab >>Primary interactions of biomass components during fast pyrolysis
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2021 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 159, article id 105297Article in journal (Refereed) Published
Abstract [en]

Fast pyrolysis is an industrially attractive method to produce fuels and chemicals from biomass; however, to gain better control over the process, the reactions and interactions between the components and decomposition products need elucidation. This study investigated primary reactions during fast pyrolysis of biomass. Pyrolysis of the three main biomass components (cellulose, hemicellulose and lignin) and their blends was carried out with a micro-pyrolyser connected to a Gas Chromatograph-Mass Spectrometer/Flame Ionisation Detector (GC–MS/FID). The blends of the individual components were prepared in similar proportions to that of native biomass (birchwood) and were pyrolysed at 600 °C for 2 s. The results showed that the two-component blends decrease the production of saccharides to a large extent. This was especially noticeable for levoglucosan when cellulose was mixed with either hemicellulose or lignin. Similarly, in the presence of cellulose, the formation of phenolic compounds from lignin was inhibited by 62 %. However, no differences were found in yields of the main products for the xylan-lignin blend compared to those from the individual components. The yields of volatile products from the cellulose-xylan blend were promoted for a majority of the product categories and were most pronounced for the aldehydes. Furthermore, while the formation of the phenols and saccharides was slightly inhibited for the three-component blend, the aldehydes, ketones and furans showed an increased production compared to the weighed sum of products expected, based on the pyrolysis of the individual components. The native biomass showed a similar trend as the three-component blend in all product categories except for the saccharides, which were inhibited to a large extent. This study provides a better understanding of the interactions occurring between different components during fast pyrolysis of biomass.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Fast pyrolysis, Primary reactions, Biomass blend, Biomass interaction, Py-GC/MS/FID
National Category
Energy Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-26536 (URN)10.1016/j.jaap.2021.105297 (DOI)000697681700003 ()2-s2.0-85113332077 (Scopus ID)
Available from: 2021-09-29 Created: 2021-09-29 Last updated: 2023-08-31
Chandolias, K., Sugianto, L. A., Izazi, N., Millati, R., Wikandari, R., Ylitervo, P., . . . Taherzadeh, M. J. (2021). Protective effect of a reverse membrane bioreactor against toluene and naphthalene in anaerobic digestion. Biotechnology and applied biochemistry
Open this publication in new window or tab >>Protective effect of a reverse membrane bioreactor against toluene and naphthalene in anaerobic digestion
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2021 (English)In: Biotechnology and applied biochemistry, ISSN 0885-4513, E-ISSN 1470-8744Article in journal (Refereed) Published
Abstract [en]

Raw syngas contains tar contaminants including toluene and naphthalene, which inhibit its conversion to methane. Cell encasement in a hydrophilic reverse membrane bioreactor (RMBR) could protect the cells from hydrophobic contaminants. This study aimed to investigate the inhibition of toluene and naphthalene and the effect of using RMBR. In this work, toluene and naphthalene were added at concentrations of 0.5?1.0 and 0.1?0.2 g/L in batch operation. In continuous operation, concentration of 0?6.44 g/L for toluene and 0?1.28 g/L for naphthalene were studied. The results showed that no inhibition was observed in batch operation for toluene and naphthalene at concentrations up to 1 and 0.2 g/L, respectively. In continuous operation of free cell bioreactors (FCBRs), inhibition of toluene and naphthalene started at 2.05 and 0.63 g/L, respectively. When they were present simultaneously, inhibition of toluene and naphthalene occurred at concentrations of 3.14 and 0.63 g/L, respectively. In continuous RMBRs, no inhibition for toluene and less inhibition for naphthalene were observed, resulting in higher methane production from RMBR than that of FCBR. These results indicated that RMBR system gave a better protection effect against inhibitors compared with FCBR.

Place, publisher, year, edition, pages
John Wiley & Sons, 2021
Keywords
anaerobic digestion, syngas contaminants, naphthalene, toluene, protective effect, reverse membrane bioreactor
National Category
Other Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-26179 (URN)10.1002/bab.2218 (DOI)000675539600001 ()34196033 (PubMedID)2-s2.0-85110966313 (Scopus ID)
Available from: 2021-08-11 Created: 2021-08-11 Last updated: 2021-08-18Bibliographically approved
Supriyanto, S., Usino, D., Ylitervo, P., Dou, J., Sipponen, M. H. & Richards, T. (2020). Identifying the primary reactions and products of fast pyrolysis of alkali lignin. Journal of Analytical and Applied Pyrolysis, 151, Article ID 104917.
Open this publication in new window or tab >>Identifying the primary reactions and products of fast pyrolysis of alkali lignin
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2020 (English)In: Journal of Analytical and Applied Pyrolysis, Vol. 151, article id 104917Article in journal (Refereed) Published
Abstract [en]

This study focused on the effect of temperature and residence time on the primary thermal decomposition reactions during a fast pyrolysis of softwood alkali lignin. The use of Py-GC/MS/FID (Micropyrolyser-Gas Chromatography/Mass Spectrometry/Flame Ionization Detector) allowed for rapid heating of the sample and detailed identification and quantification of the pyrolysis products at a temperature range of 400–600 °C, with residence times from 0.5–5 s. The identified primary pyrolysis products were mainly volatile guaiacyl-type compounds. There was a general increase in yield for the majority of the volatile compounds with increased temperature and time. The cleavage of the lignin polymer to linear carbonyl (acetaldehyde) and guaiacyl-type aromatic compounds increased with temperature, while that of catechol and cresol type was mainly favoured at 500 and 600 °C. Based on these results, a mechanistic pathway for the pyrolytic process was proposed, drawing a linkage from structural units of lignin to the formed primary products. In summary, our findings suggest that the primary decomposition reactions that occur under the fast pyrolysis conditions can be controlled by varying the process temperature and residence time, and deliver mechanistic insight into the product distribution from structurally complex lignin material.

Keywords
Fast pyrolysis, Lignin, Primary reactions, Py-GC/MS/FID
National Category
Engineering and Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-23812 (URN)10.1016/j.jaap.2020.104917 (DOI)000580632500014 ()2-s2.0-85091261216 (Scopus ID)
Available from: 2020-09-18 Created: 2020-09-18 Last updated: 2023-08-31Bibliographically approved
Usino, D., Supriyanto, S., Ylitervo, P., Pettersson, A. & Richards, T. (2020). Influence of temperature and time on initial pyrolysis of cellulose and xylan. Journal of Analytical and Applied Pyrolysis, Volume 147(104782)
Open this publication in new window or tab >>Influence of temperature and time on initial pyrolysis of cellulose and xylan
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2020 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. Volume 147, no 104782Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to investigate the effects of temperature and reaction time on the primary pyrolysis of cellulose and xylan. Fast pyrolysis of cellulose and xylan was carried out with a micropyrolyser connected to a gas chromatograph-mass spectrometer/flame ionisation detector (GC–MS/FID) to separate and identify volatile components, both qualitatively and quantitatively. This set-up meant a minimum amount of secondary reactions, low impact of the heating period and at the same time provided rapid and accurate analyses. The two biomass components investigated were: cellulose and hemicellulose (represented by xylan). They were pyrolysed during 0.5, 1, 2 and 5 s (s) and within a temperature range of 400–600 °C. The results showed that levoglucosan (1, 6-anhydro β-D-glucopyranose) is the main chemical compound released during cellulose pyrolysis. It increased with increasing temperature and time. The main volatile compounds produced from pyrolysis of xylan are: 1-hydroxy-2-butanone, 4-hydroxy-5, 6-dihydro-(2 H)-pyran-2-one, 1-hydroxy-2-propanone (acetol), acetaldehyde and hydroxyacetaldehyde (HAA). HAA was the most abundant chemical compound released during xylan pyrolysis, increasing with higher temperatures and time. Acetol and acetaldehyde also showed similar behaviour. The chemical compounds released from cellulose and xylan fast pyrolysis are primary products and assumed to be produced directly from both cellulose and xylan molecules and not from secondary degradation. In this study, possible reaction routes during biomass primary pyrolysis are also suggested based on the product distribution from the thermal decomposition of cellulose and xylan.

Keywords
Fast pyrolysis, Primary reactions, Py-GC-MS/FID, Cellulose, Xylan
National Category
Engineering and Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-23155 (URN)10.1016/j.jaap.2020.104782 (DOI)000523305000007 ()2-s2.0-85079271304 (Scopus ID)
Available from: 2020-04-24 Created: 2020-04-24 Last updated: 2023-08-31Bibliographically approved
Sárvári Horváth, I., del Pilar Castillo, M., Schnürer, A., Agnihotri, S., Ylitervo, P. & Edström, M. (2017). Utilization of Straw Pellets and Briquettes as Co-Substrates at Biogas Plants.
Open this publication in new window or tab >>Utilization of Straw Pellets and Briquettes as Co-Substrates at Biogas Plants
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2017 (English)Report (Other academic)
Abstract [en]

Biogas reactors can be utilized more efficiently when straw and food waste are digested together instead of separately. In the present study, straw in the form of pellets and briquettes has been used in experiments and calculations. Co-digestion of different substrates can give a more optimal substrate composition and a more efficient utilization of available digester volume. The pelleting and briquetting process has been shown to be an adequate pretreatment method of the straw. Digesting food waste and straw together showed synergistic effects with improved degradation of the food waste as well as a higher total volumetric methane production as compared to when food waste was used as the sole substrate. Energy produced through increased biogas production was higher than the energy needed for the pelleting and briquetting process. The positive effect in regard to gas production was mainly seen for the straw pellets, results supported by both chemical and microbiological analysis. These effects were observed in both mesophilic and thermophilic conditions. In conclusion, this study illustrates that straw is a suitable co-digestion substrate to food waste and can be used to improve gas yields as well as for more efficient utilization of the digester volume. These results show the biogas potential of straw, today not yet used as a substrate to a large extent.

Publisher
p. 58
Series
EnergiForsk REPORT 2017:438
National Category
Bioenergy
Identifiers
urn:nbn:se:hb:diva-13564 (URN)
Available from: 2018-01-17 Created: 2018-01-17 Last updated: 2018-01-18Bibliographically approved
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