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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
Kharrazi, S. M., Soleimani, M., Jokar, M., Richards, T., Pettersson, A. & Mirghaffari, N. (2021). Pretreatment of lignocellulosic waste as a precursor for synthesis of high porous activated carbon and its application for Pb (II) and Cr (VI) adsorption from aqueous solutions. International Journal of Biological Macromolecules, 180, 299-310
Open this publication in new window or tab >>Pretreatment of lignocellulosic waste as a precursor for synthesis of high porous activated carbon and its application for Pb (II) and Cr (VI) adsorption from aqueous solutions
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2021 (English)In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 180, p. 299-310Article in journal (Refereed) Published
Abstract [en]

Effects of Elm tree sawdust pretreatments using alkali and alkaline earth metals (NaCl, KCl, CaCl2, MgCl2 and Elm tree ash) and deashing solutions (water, HCl, HNO3 and aqua regia) before the carbonization process on the porosity of produced activated carbons and Pb (II) and Cr (VI) adsorption were studied. The activated carbons were characterized by pore size distribution, surface area, FTIR, and SEM-EDX analysies. Based on the results, HCl leaching pretreatment of the biomass increased the activated carbon adsorption capacity of Cr (VI) from 114 to 190 mg g−1. The treatment of biomass with alkali and alkali earth metal salts, especially MgCl2, remarkably increased the activated carbon adsorption capacity of Pb (II) from 233 to 1430 mg g−1. The results indicated that Pb (II) adsorption was attributed to both the mesoporous structure of activated carbon and the abundance of Mg on the activated carbon's surface. On the other hand, the micropores played a major role in Cr (VI) adsorption capacity. The development of the micro- or mesoporous structure of activated carbons through pretreatment of lignocellulosic precursor could be an approach for providing high performance activated carbons for Pb (II) and Cr (VI) removal from aqueous solutions.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Chemical activation, Elm tree, Heavy metals
National Category
Environmental Sciences
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-25921 (URN)10.1016/j.ijbiomac.2021.03.078 (DOI)000649643500013 ()33737183 (PubMedID)2-s2.0-85102625569 (Scopus ID)
Available from: 2021-07-09 Created: 2021-07-09 Last updated: 2021-07-13Bibliographically approved
Vali, N., Åmand, L.-E., Combres, A., Richards, T. & Pettersson, A. (2021). Pyrolysis of municipal sewage sludge to investigate char and phosphorous yield together with heavy-metal removal—experimental and by thermodynamic calculations. Energies, 14(5), Article ID 1477.
Open this publication in new window or tab >>Pyrolysis of municipal sewage sludge to investigate char and phosphorous yield together with heavy-metal removal—experimental and by thermodynamic calculations
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2021 (English)In: Energies, E-ISSN 1996-1073, Vol. 14, no 5, article id 1477Article in journal (Refereed) Published
Abstract [en]

Sewage sludge is regarded as a potential source for soil fertilizer However, the direct utilization of sewage sludge in agricultural land is restricted since it also contains heavy metals, pathogens, and toxic compounds. Pyrolysis of the sewage sludge destroys the organic pollutants and partly volatilizes the heavy metals. In this study, pyrolysis of sewage sludge was carried out in order to determine the optimum residence time and temperature to recover the phosphorous and remove heavy metals from the resultant sewage sludge char (SSC). Pyrolysis was conducted on dried sewage sludge (DSS) by means of thermogravimetric analysis (TGA) and high-temperature oven with an N2-atmosphere. Microwave Plasma-Atomic Emission Spectroscopy (MP-AES) was used to determine the concentration of P and trace elements in the resulting solid char fraction. A combination of chemical fractionation (step-by-step leaching) of the DSS and thermodynamic equilibrium calculations were utilized to estimate the availability of phosphorous and removal of heavy metals in the SSC fraction at different temperatures. The results from the thermodynamics calculation were in line with the measured chemical composition of the SSC. Furthermore, the energy contents of the SSC obtained at different temperatures were measured. The pyrolysis evaluation results indicate that phosphorous was enriched in the char, while lead, zinc, and cadmium were significantly removed.

Keywords
Chemical fractionation, Phosphorus recovery, Pyrolysis, Sewage sludge, Thermodynamic equilibrium modeling, Agricultural robots, Atomic emission spectroscopy, Heavy metals, Organic pollutants, Phosphorus, Thermogravimetric analysis, Trace elements, Chemical compositions, Dried sewage sludge, Heavy metal removal, Municipal sewage sludge, Thermodynamic calculations, Thermodynamic equilibrium calculation, Thermodynamics calculations, Atmospheric temperature
National Category
Energy Engineering
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-25948 (URN)10.3390/en14051477 (DOI)000628159600001 ()2-s2.0-85106217062 (Scopus ID)
Available from: 2021-07-09 Created: 2021-07-09 Last updated: 2023-08-28
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
Eboh, F. C., Andersson, B.-Å. & Richards, T. (2019). Economic evaluation of improvements in a waste-to-energy combined heat and power plant. Waste Management
Open this publication in new window or tab >>Economic evaluation of improvements in a waste-to-energy combined heat and power plant
2019 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456Article in journal (Refereed) Published
Abstract [en]

Improving the efficiency of waste-to-energy combined heat and power plants increases their production of both electricity and heat. Economic evaluation of such improvements enables adequate decisions to be made between the various alternatives with respect to economic viability of the plant. In this study, the cost and profitability of different modifications to improve efficiency in a waste-to-energy plant are considered: these include the re-arrangement of air heaters, the introduction of a reheater, flue gas condensation (FGC) and an integrated gasification-combustion process. The base case and the modifications are evaluated and compared when operating either as a combined heat and power plant or as a power plant. Modelling, simulation and cost estimations were performed with the Aspen Plus software. Although the integrated gasification-combustion technology with FGC has the highest exergy efficiency, its higher capital cost is greater than all of the other alternatives. Modification 6, which involves both re-arrangement and changing the air heating medium has the lowest capital cost with respect to enhancing exergy efficiency. Modifications 1 and 7, involving FGC, are the best alternatives for the capital cost per total unit of revenue generated. These modifications not only provides the highest heat production but also the highest net present value (NPV). The base case and the modifications investigated all have positive NPV, indicating that a waste-to-energy combined heat and power plant is an attractive investment. However, an increase of about 122% in the gate fees would be required for a system with only electricity production to be profitable.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Waste-to-energy plant, Efficiency improvement, Economic viability, Cost of improvement
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hb:diva-21730 (URN)10.1016/j.wasman.2019.09.008 (DOI)000494887900009 ()2-s2.0-85072213171 (Scopus ID)
Available from: 2019-09-14 Created: 2019-09-14 Last updated: 2020-01-28Bibliographically approved
Eboh, F. C., Ahlström, P. & Richards, T. (2019). Evaluating improvements in a waste-to-energy combined heat and power plant. Case Studies in Thermal Engineering
Open this publication in new window or tab >>Evaluating improvements in a waste-to-energy combined heat and power plant
2019 (English)In: Case Studies in Thermal Engineering, ISSN 2214-157XArticle in journal (Refereed) Published
Abstract [en]

Evaluation of different alternatives for enhancement in a waste combustion process enables adequate decisions to be made for improving its efficiency. Exergy analysis has been shown be an effective tool in assessing the overall efficiency of a system. However, the conventional exergy method does not provide information of the improvements possible in a real process. The purpose of this paper is to evaluate state-of-the art techniques applied in a municipal solid-waste fired heat and power plant. The base case plant is evaluated first; the results are then used to decide upon which technical modifications should be introduced and they are thereafter evaluated. A modified exergy-based method is used to discover the improvement potential of both the individual components and the overall base case plant. The results indicate that 64% of exergy destruction in the overall process can theoretically be improved. The various modifications selected involve changing the bed material, using a gasifier followed by a gas boiler and incorporating a more durable material into the boiler walls. In addition, changing the heating medium of the incoming air (from steam to flue gas) along with a reduction in the stack temperature and the integration of flue gas condensation were considered for utilizing the exergy in the flue gases. The modification involving gasifier, gas boiler and flue gas condensation proved to be the best option, with the highest exergy efficiency increment of 21%.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Theoretical process, Exergy efficiency, Flue gas condensation, Municipal solid-waste fired plant, Improvement potential, Gasification-combustion process
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hb:diva-21729 (URN)10.1016/j.csite.2019.100476 (DOI)000487833400035 ()2-s2.0-85067188415 (Scopus ID)
Available from: 2019-09-14 Created: 2019-09-14 Last updated: 2020-01-29Bibliographically approved
Chandolias, K., Richards, T. & Taherzadeh, M. J. (2018). Combined gasification-fermentation process in waste biorefinery. In: Waste Biorefinery: Potential and Perspectives. Elsevier
Open this publication in new window or tab >>Combined gasification-fermentation process in waste biorefinery
2018 (English)In: Waste Biorefinery: Potential and Perspectives, Elsevier, 2018Chapter in book (Refereed)
Abstract [en]

Thermal processes of wastes lead to production of energy in form of electricity and/or heat. However, if the goal is to produce materials, thermochemical processes can be applied. These processes via e.g. gasification produce raw syngas that is a mixture of principally H2, CO and CO2, with some impurities. This raw syngas is traditionally cleaned and catalytically treated via chemical processes such as Fischer-Tropsch. However, as there is a variety of microorganisms that can assimilate syngas, this gas can be used as a substrate to produce different chemicals via biochemical routes. This chapter is dedicated to describe an efficient thermochemical-biochemical route of waste treatment. The gasification process, the design and the factors that affect the syngas composition are firstly described. Thereafter, the microbiology, biochemical reactions, metabolic pathways and process conditions toward production of several metabolic products from syngas such as carboxylic acids, ethanol, butanol, 2,3-butanediol, methane and biopolymers are presented. 

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Gasification, Fermentation, Biofuels, Valuable chemicals
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hb:diva-14190 (URN)9780444639929 (ISBN)
Funder
Swedish Research Council
Available from: 2018-05-16 Created: 2018-05-16 Last updated: 2018-06-21Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0037-3555

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