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Persson, H. & Duman, I. (2019). Catalytic pyrolysis over transition metal-modified zeolites: a comparative study between catalyst activity and deactivation. Journal of Analytical and Applied Pyrolysis
Open this publication in new window or tab >>Catalytic pyrolysis over transition metal-modified zeolites: a comparative study between catalyst activity and deactivation
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2019 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250XArticle in journal (Refereed) Published
Abstract [en]

The utilization of metal-doped zeolites in catalytic pyrolysis of biomass is a well-known approach to promote the formation of certain compounds. One major technical issue of using zeolites in biomass pyrolysis processes is their rapid deactivation due to coke formation. However, little is known about how metal-doping influences the characteristics of coking, such as coking rate and its composition.

In this study, four different materials were experimentally evaluated based on their catalytic activity and coking characteristics: HZSM-5, Fe/ZSM-5, Ni/ZSM-5 and FeNi/ZSM-5. The materials were prepared and characterized followed by screening in a bench-scale setup for in-situ catalytic pyrolysis. The mass balance and composition of pyrolysis products including catalyst coke were analyzed.

It was found that metal-doping increases the concentration of aromatic hydrocarbons in the liquid product from 59.0 to 82.8 % of GC/MS peak area, especially monoaromatic hydrocarbons (MAHs) and naphthalenes. Fe mainly promotes MAHs whereas Ni additionally promotes naphthalenes. FeNi/ZSM-5 enhances the production of both compound groups as well as further reducing the total acid number (TAN). Regarding the catalyst coke, metal-doped catalysts present an increased concentration of aromatic hydrocarbons in terms of MAHs, naphthalenes and polyaromatic hydrocarbons. For each catalyst, the chemical composition of catalyst coke reflects the catalyst’s activity seen in vapor upgrading. A reaction pathway based on the observed catalyst activities of metal-doped ZSM-5 and HZSM-5 is proposed.

The results also show that metal-doping of catalysts increases the formation of catalyst coke, mainly due to a higher concentration of strong acid sites. Also, the rate of coking is dependent on the strength of acid sites, where the strength correlates with the severity of coking. The coke yield was seen to increase from 3.5 wt% in the case of HZSM-5 to maximum 7.2 wt% over Fe/ZSM-5. However, the metal-doping of catalysts reduces the temperature of catalyst regeneration and catalyzes the oxidation of coke. Overall, this work presents a comparative study between catalyst activity and deactivation during thermochemical conversion of biomass.

National Category
Engineering and Technology
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-239877 (URN)10.1016/j.jaap.2018.12.005 (DOI)
Note

QC 20181206

Available from: 2018-12-04 Created: 2018-12-04 Last updated: 2018-12-06Bibliographically approved
Han, T., Sophonrat, N., Tagami, A., Sevastyanova, O., Mellin, P. & Yang, W. (2019). Characterization of lignin at pre-pyrolysis temperature to investigate its melting problem. Fuel, 235, 1061-1069
Open this publication in new window or tab >>Characterization of lignin at pre-pyrolysis temperature to investigate its melting problem
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2019 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 235, p. 1061-1069Article in journal (Refereed) Published
Abstract [en]

Technical lignin particles melt under relatively low temperature. This results in the problem in the continuous feeding and fluidization during lignin pyrolysis, which in turn limits its utilization on a large scale. In this study, two most available types of lignin have been used to investigate the lignin melting problem, which are Kraft lignin (KL) from pulping process and hydrolysis lignin (HL) from bio-ethanol production process. Elemental composition, thermal property and thermally decomposed derivatives of each sample are tested by elemental analyzer, TGA, DSC, and Py-GC/MS. Morphology, structure and crystal change before and after heat treatment are tested by microscopy, FTIR and XRD. All results suggest that lignin structure determines its melting properties. Kraft lignin from pulping process contains a less cross-linked structure. It melts under heating. On the other hand, hydrolysis lignin from hydrolysis process contains a highly crossed-linked and condensed structure. It does not melt before decomposition under heat treatment. Modifying lignin structure is suggested for the resolution of technical lignin melting problem.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2019
Keywords
Kraft lignin (KL), Hydrolysis lignin (HL), Melting properties, Structure
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-238521 (URN)10.1016/j.fuel.2018.08.120 (DOI)000447791900105 ()
Note

QC 20181106

Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2018-11-06Bibliographically approved
Han, T., Sophonrat, N., Tagami, A., Sevastyanova, O., Mellin, P. & Yang, W. (2019). Characterization of lignin at pre-pyrolysis temperature to investigate its melting problem. Fuel, 235, 1061-1069
Open this publication in new window or tab >>Characterization of lignin at pre-pyrolysis temperature to investigate its melting problem
Show others...
2019 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 235, p. 1061-1069Article in journal (Refereed) Published
Abstract [en]

Technical lignin particles melt under relatively low temperature. This results in the problem in the continuous feeding and fluidization during lignin pyrolysis, which in turn limits its utilization on a large scale. In this study, two most available types of lignin have been used to investigate the lignin melting problem, which are Kraft lignin (KL) from pulping process and hydrolysis lignin (HL) from bio-ethanol production process. Elemental composition, thermal property and thermally decomposed derivatives of each sample are tested by elemental analyzer, TGA, DSC, and Py-GC/MS. Morphology, structure and crystal change before and after heat treatment are tested by microscopy, FTIR and XRD. All results suggest that lignin structure determines its melting properties. Kraft lignin from pulping process contains a less cross-linked structure. It melts under heating. On the other hand, hydrolysis lignin from hydrolysis process contains a highly crossed-linked and condensed structure. It does not melt before decomposition under heat treatment. Modifying lignin structure is suggested for the resolution of technical lignin melting problem.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Hydrolysis lignin (HL), Kraft lignin (KL), Melting properties, Structure, Crystal structure, Fluidization, Heat treatment, Hydrolysis, Melting, Pulp manufacture, Pyrolysis, Structure (composition), Temperature, After-heat treatment, Bio-ethanol production, Crosslinked structures, Elemental compositions, Hydrolysis lignins, Kraft lignin, Pyrolysis temperature, Lignin
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-236342 (URN)10.1016/j.fuel.2018.08.120 (DOI)000447791900105 ()2-s2.0-85052512069 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20181108

Available from: 2018-11-08 Created: 2018-11-08 Last updated: 2018-11-08Bibliographically approved
Wang, S., Persson, H., Weihong, Y. & Jönsson, P. (2018). Effect of H2 as Pyrolytic Agent on the Product Distribution during Catalytic Fast Pyrolysis of Biomass Using Zeolites. Energy & Fuels
Open this publication in new window or tab >>Effect of H2 as Pyrolytic Agent on the Product Distribution during Catalytic Fast Pyrolysis of Biomass Using Zeolites
2018 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029Article in journal (Refereed) Published
Abstract [en]

Bio-oil generated from catalytic fast pyrolysis or hydrotreating processes represents one of the most promising alternatives to liquid fossil fuels. The use of H2 as carrier gas in the pyrolysis of biomass requires further research to study the catalytic fast pyrolysis reactions in the case of using reactive atmosphere. In this work, pyrolysis experiments with lignocellulosic biomass have been performed in a fixed bed reactor in H2 and N2 atmospheres with/without HZSM-5 additions to investigate the influence of the pyrolytic agents during fast pyrolysis of biomass and upgrading of pyrolytic vapors over a zeolitic catalyst. It was found that in a H2 atmosphere, H2 was consumed in both noncatalytic and catalytic pyrolysis processes, respectively. Higher yields of nonaqueous liquids and permanent gases are obtained in a H2 atmosphere compared to a N2 atmosphere. A catalytic pyrolysis process using HZSM-5 in a H2 atmosphere increased the production of polymer aromatic hydrocarbons and suppressed the production of monomer aromatic hydrocarbons compared to similar tests performed in a N2 atmosphere. The results show an overall increased activity of HZSM-5 in the reactive H2 atmosphere compared to a N2 atmosphere.

Keywords
biomass, pyrolysis, hydrogen, HZSM-5, 生物质, 生物燃料, HZSM-5, 催化裂解, 氢气
National Category
Bioenergy Chemical Engineering Biochemicals
Research subject
Chemical Engineering; Energy Technology; Biotechnology
Identifiers
urn:nbn:se:kth:diva-232341 (URN)10.1021/acs.energyfuels.8b01779 (DOI)000442448300052 ()2-s2.0-85049616561 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 2018-07-20

Available from: 2018-07-19 Created: 2018-07-19 Last updated: 2018-09-07Bibliographically approved
Han, T., Sophonrat, N., Evangelopoulos, P., Persson, H., Weihong, Y. & Jönsson, P. (2018). Evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin. Journal of Analytical and Applied Pyrolysis, 33, 162-168
Open this publication in new window or tab >>Evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin
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2018 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 33, p. 162-168Article in journal (Refereed) Published
Abstract [en]

Sulfonated Kraft lignin, the most available commercial lignin of today, has high sulfur content due to the extraction and the subsequent sulfonation processes. In this work, the evolution of sulfur during fast pyrolysis of sulfonated Kraft lignin has been studied. Fast Pyrolysis experiments have been done using Py-GC/MS. It is found that main sulfur-containing products in the pyrolytic vapors are present as the following small molecular compounds: H2S, SO2, CH3SH, CH3SCH3, and CH3SSCH3. This indicates that sulfur-containing radicals preferentially combine with the other small radicals such as H and CH3 during fast pyrolysis process. Sulfur is suggested to be mainly present as sulfite (SO3) and sulfide (S) in the sulfonated Kraft lignin. Sulfite that is incorporated into lignin during the sulfonation process mainly result in the formation of SO2. The nature of the sulfur links created during the Kraft pulping process is difficult to determine, but they are supposed to mainly exist in form of sulfide (S) bonds, which lead to the formation of H2S, CH3SH, CH3SCH3 and CH3SSCH3.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Chemical Engineering Materials Engineering
Identifiers
urn:nbn:se:kth:diva-229683 (URN)10.1016/j.jaap.2018.04.006 (DOI)000435747900020 ()2-s2.0-85045121473 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20180611

Available from: 2018-06-05 Created: 2018-06-05 Last updated: 2018-07-23Bibliographically approved
Wan, W., Engvall, K., Yang, W. & Möller, B. F. (2018). Experimental and modelling studies on condensation of inorganic species during cooling of product gas from pressurized biomass fluidized bed gasification. Energy, 153, 35-44
Open this publication in new window or tab >>Experimental and modelling studies on condensation of inorganic species during cooling of product gas from pressurized biomass fluidized bed gasification
2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 153, p. 35-44Article in journal (Refereed) Published
Abstract [en]

In a biomass gasification process, condensation of inorganic species can cause problems such as corrosion and deposition on the downstream equipment. In this work, in order to investigate the condensation of inorganics during the gas cooling step of the biomass gasification system, both experimental and modelling studies were conducted. Experiments were performed on a pilot-scale steam/oxygen blown fluidized bed gasification facility. A CO2 cooled probe was located at the head of a filter to condense inorganic species. Five thermocouples were used to monitor the probe temperature profile. Deposits on the probe were characterized using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) to analyze the elemental composition of deposits. A process model based on the local chemical and phase equilibriums was developed using software SimuSage to predict both release and condensation of inorganics. A customized thermodynamic database extracted from the FactSage 7.1 was used during model calculations. Two cases including with and without addition of bed material were calculated. Results show that the identified elemental compositions of deposit under different gas cooling temperatures reasonably agree with the elemental compositions predicted by model calculations. This demonstrates that the established model and the customized thermodynamic data are valid. A large amount of carbon is identified in the deposit of low temperature probe sections, which may come from the condensed tar. Additionally, a temperature window is found, where melts are formed during gas cooling.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Biomass, Inorganics, Condensation, Gasification
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-234209 (URN)10.1016/j.energy.2018.04.031 (DOI)000436651100005 ()2-s2.0-85046675283 (Scopus ID)
Note

QC 20180905

Available from: 2018-09-05 Created: 2018-09-05 Last updated: 2018-11-29Bibliographically approved
Persson, H., Han, T., Xia, W., Evangelopoulos, P. & Weihong, Y. (2018). Fractionation of liquid products from pyrolysis of lignocellulosic biomass by stepwise thermal treatment. Energy, 154, 346-351
Open this publication in new window or tab >>Fractionation of liquid products from pyrolysis of lignocellulosic biomass by stepwise thermal treatment
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2018 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 154, p. 346-351Article in journal (Refereed) Published
Abstract [en]

The thermal properties of cellulose, hemicellulose and lignin can be utilized to improve the characteristics of pyrolysis liquids. In this study, a concept of stepwise pyrolysis to fractionate the liquid based on the thermal properties of the biomass constituents was investigated. Lignocellulosic biomass was thermally treated in two steps: 200–300 °C followed by 550 °C. Derived liquids were studied for GC/MS analysis, water content, acid concentration and a solvent extraction method. Pyrolytic liquid derived from 550 °C after treatment at lower temperatures have a higher relative composition of phenolic compounds compared to one-step pyrolysis (increased from 58 to 90% of GC/MS peak area). Also, compounds known to promote aging, such as acids and carbonyl compounds, are derived at lower temperatures which may suppress aging in the liquid derived downstream at 550 °C. For liquids derived at 550 °C, the total acid number was reduced from 125 in one-step treatment to 14 in two-step treatment. Overall, no significant difference in the total liquid yield (sum of the liquids derived in separated treatments) nor any variations in their collective composition compared to one-step treatment at 550 °C was observed, i.e. stepwise pyrolysis can be utilized for direct fractionation of pyrolytic vapors.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Pyrolysis Biomass Bio-oil Stepwise Fractionation
National Category
Engineering and Technology
Research subject
Chemical Engineering; Chemistry; Energy Technology; Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-227249 (URN)10.1016/j.energy.2018.04.150 (DOI)000436886200033 ()2-s2.0-85046167007 (Scopus ID)
Funder
Swedish Energy Agency, 33284-2Swedish Energy Agency, 39449-1
Note

QC 20180522

Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2018-07-17Bibliographically approved
Kabalina, N., Costa, M., Weihong, Y. & Martin, A. R. (2018). Impact of a reduction in heating, cooling and electricity loads on the performance of a polygeneration district heating and cooling system based on waste gasification. Energy Journal, 151, 594-604
Open this publication in new window or tab >>Impact of a reduction in heating, cooling and electricity loads on the performance of a polygeneration district heating and cooling system based on waste gasification
2018 (English)In: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 151, p. 594-604Article in journal (Refereed) Published
Keywords
polygeneration, district heating and cooling, refuse derived fuel, municipal solid waste, gasification
National Category
Other Engineering and Technologies Environmental Engineering
Identifiers
urn:nbn:se:kth:diva-226907 (URN)10.1016/j.energy.2018.03.078 (DOI)000432509000051 ()2-s2.0-85046033334 (Scopus ID)
Note

QC 20180504

Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2018-06-13Bibliographically approved
Evangelopoulos, P., Sophonrat, N., Jilvero, H. & Weihong, Y. (2018). Investigation on the low-temperature pyrolysis of automotive shredder residue (ASR) for energy recovery and metal recycling. Waste Management, 76, 507-515
Open this publication in new window or tab >>Investigation on the low-temperature pyrolysis of automotive shredder residue (ASR) for energy recovery and metal recycling
2018 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 76, p. 507-515Article in journal (Refereed) Published
Abstract [en]

The automotive shredder residue (ASR) or shredder light fraction (SLF) is the remaining fraction from the metal recovery of end-of-life vehicles (ELVs). While processes for metal recovery from ELVs are well developed, the similar process for ASR remains a challenge. In this work, low-temperature pyrolysis of the ASR fraction was investigated under the assumption that a low temperature and inert environment would enhance the metal recovery, i.e. the metals would not be further oxidised from their original state and the organic material could be separated from the metals in the form of volatiles and char. Pyrolysis experiments were performed in a tube reactor operating at 300, 400 and 500 degrees C. The gas and oil obtained by pyrolysis were analysed by micro-GC (micro-Gas Chromatography) and GC/MS (Gas Chromatography/Mass Spectrometry), respectively. It was found that the gas produced contained a high amount of CO2, limiting the energy recovery from this fraction. The oil consisted of a high concentration of phenolic and aromatic compounds. The solid residue was crushed and fractionated into different particle sizes for further characterization. The pyrolysis temperature of 300 degrees C was found to be insufficient for metal liberation, while the char was easier to crush at tested temperature of 400 and 500 degrees C. The intermediate temperature of 400 degrees C is then suggested for the process to keep the energy consumption low.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2018
Keywords
Automotive shredder residues (ASR), Pyrolysis, Metal recovery, Thermal treatment, Shredder light fraction (SLF), End-of-life vehicles (ELVs)
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-231730 (URN)10.1016/j.wasman.2018.03.048 (DOI)000435064000050 ()29628362 (PubMedID)2-s2.0-85044935411 (Scopus ID)
Note

QC 20180814

Available from: 2018-08-14 Created: 2018-08-14 Last updated: 2018-11-06Bibliographically approved
Lousada, C. M., Sophonrat, N. & Weihong, Y. (2018). Mechanisms of Formation of H, HO, and Water and of Water Desorption in the Early Stages of Cellulose Pyrolysis. The Journal of Physical Chemistry C, 122(23), 12168-12176
Open this publication in new window or tab >>Mechanisms of Formation of H, HO, and Water and of Water Desorption in the Early Stages of Cellulose Pyrolysis
2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 23, p. 12168-12176Article in journal (Refereed) Published
Abstract [en]

Here, we report the results from a combined first-principles and experimental investigation of the initial stages of decomposition of cellulose during heating in pyrolysis. Density functional theory calculations with periodic boundary conditions were performed to investigate the formation of H and HO radicals and of the molecular products H2O, H-2, and H2O2 originating from their recombination. The stabilization that alcohol groups impart to adjacent C-radicals and the allylic recombination of unpaired electrons of neighboring C-radicals play decisive roles in the decomposition mechanism. This makes the simultaneous formation of H-center dot from C2 and HO center dot from C3 the most favorable process. The recombination of these radicals to form water leads to an additional stabilization of the reaction. The computed temperature-dependent reactions Gibbs' free energies reveal that desorption of H2O from intact cellulose occurs at T = 147 degrees C and that gas-phase water forms spontaneously from the decomposition of cellulose at T = 282 degrees C. These results are in excellent agreement with our experimental study of the pyrolysis done with pyrolysis gas chromatography/mass spectrometry at different temperatures. The experiments show that upon heating, a small amount of water is released from cellulose at 210 degrees C, and a considerably larger amount starts to be released at 280 degrees C.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-231703 (URN)10.1021/acs.jpcc.8b02173 (DOI)000435611900005 ()2-s2.0-85047430208 (Scopus ID)
Note

QC 20180822

Available from: 2018-08-22 Created: 2018-08-22 Last updated: 2018-08-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1837-5439

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