Catalytic conversion of acetol over HZSM-5 catalysts – influence of Si/Al ratio and introduction of mesoporosity.
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| Title: | Catalytic conversion of acetol over HZSM-5 catalysts – influence of Si/Al ratio and introduction of mesoporosity. |
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| Authors: | Eschenbacher, Andreas1 (AUTHOR), Andersen, Jakob Afzali1 (AUTHOR), Jensen, Anker Degn1 (AUTHOR) aj@kt.dtu.dk |
| Source: | Catalysis Today. Apr2021, Vol. 365, p301-309. 9p. |
| Subjects: | Hydroxypropanone, Gas phase reactions, Silicon alloys, Mesoporous materials, Catalysts, Catalyst poisoning, Liquid hydrocarbons |
| Abstract: | [Display omitted] • Catalyst screening with acetol as representative pyrolysis vapor compound. • Three parent HZSM-5 and four mesoporous HZSM-5 tested after steam treatment. • Coking propensity increased after introduction of mesopores. • Mesoporous HZSM-5 samples showed improved tolerance towards deactivation. Crude bio-oil from fast pyrolysis of biomass has a high oxygen content and acidity, leading to problems with corrosion and polymerization/instability. In this work, the catalytic vapor phase upgrading of acetol, a compound that is present in high concentrations in pyrolysis vapors, was investigated over three microporous HZSM-5 and four mesoporous HZSM-5 catalysts with different levels of acidity and mesoporosity. All catalysts were steam-treated prior to testing in order to attribute deactivation unambiguously to coking rather than simultaneously occurring dealumination, and catalysts were characterized by Ar and N 2 physisorption, NH 3 -TPD, Pyridine-IR, TEM, and XRD. With increasing temperature from 400 to 500 °C the gas yield increased while the coke yield decreased, along with increased acetol conversion and increased selectivities to oxygen-free hydrocarbons in the liquid phase. Catalyst screening was conducted at 450 °C by studying the conversion of acetol as a function of increased amounts of fed reactant. CO and ethene were the major reaction products in the gas phase. At high conversions, the condensed liquid contained olefins such as iso-butene and BTX monoaromatics. With increasing amounts of acetol fed, the selectivity to oxygen-free hydrocarbons decreased while the concentration of oxygenated compounds such as ethers, ketones, and furans increased. Simultaneously, coke formation rapidly decreased the weak and strong acid sites of the zeolites. A maximum monoaromatics yield of ∼5 wt.% of fed acetol was achieved in the initial upgrading phase for the purely microporous zeolites with Si/Al = 15 and 29, while mesoporous HZSM-5 showed slightly lower yields of monoaromatics. While the coking propensity increased after introduction of mesopores, all mesoporous catalysts showed an improved capacity for converting acetol compared to their microporous versions. Mesoporous HSZM-5 prepared via desilication of parent HZSM-5 (Si/Al = 15) with a mixture of NaOH and a pore-directing agent showed the highest tolerance towards deactivation, which is attributed to a favorable combination of acid strength and the preservation of crystallinity and microporous volume with well distributed mesopores, improving the accessibility of reactants to active sites. [ABSTRACT FROM AUTHOR] |
| Copyright of Catalysis Today is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 149687104 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Catalytic conversion of acetol over HZSM-5 catalysts – influence of Si/Al ratio and introduction of mesoporosity. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Eschenbacher%2C+Andreas%22">Eschenbacher, Andreas</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Andersen%2C+Jakob+Afzali%22">Andersen, Jakob Afzali</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Jensen%2C+Anker+Degn%22">Jensen, Anker Degn</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> aj@kt.dtu.dk</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Catalysis+Today%22">Catalysis Today</searchLink>. Apr2021, Vol. 365, p301-309. 9p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Hydroxypropanone%22">Hydroxypropanone</searchLink><br /><searchLink fieldCode="DE" term="%22Gas+phase+reactions%22">Gas phase reactions</searchLink><br /><searchLink fieldCode="DE" term="%22Silicon+alloys%22">Silicon alloys</searchLink><br /><searchLink fieldCode="DE" term="%22Mesoporous+materials%22">Mesoporous materials</searchLink><br /><searchLink fieldCode="DE" term="%22Catalysts%22">Catalysts</searchLink><br /><searchLink fieldCode="DE" term="%22Catalyst+poisoning%22">Catalyst poisoning</searchLink><br /><searchLink fieldCode="DE" term="%22Liquid+hydrocarbons%22">Liquid hydrocarbons</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: [Display omitted] • Catalyst screening with acetol as representative pyrolysis vapor compound. • Three parent HZSM-5 and four mesoporous HZSM-5 tested after steam treatment. • Coking propensity increased after introduction of mesopores. • Mesoporous HZSM-5 samples showed improved tolerance towards deactivation. Crude bio-oil from fast pyrolysis of biomass has a high oxygen content and acidity, leading to problems with corrosion and polymerization/instability. In this work, the catalytic vapor phase upgrading of acetol, a compound that is present in high concentrations in pyrolysis vapors, was investigated over three microporous HZSM-5 and four mesoporous HZSM-5 catalysts with different levels of acidity and mesoporosity. All catalysts were steam-treated prior to testing in order to attribute deactivation unambiguously to coking rather than simultaneously occurring dealumination, and catalysts were characterized by Ar and N 2 physisorption, NH 3 -TPD, Pyridine-IR, TEM, and XRD. With increasing temperature from 400 to 500 °C the gas yield increased while the coke yield decreased, along with increased acetol conversion and increased selectivities to oxygen-free hydrocarbons in the liquid phase. Catalyst screening was conducted at 450 °C by studying the conversion of acetol as a function of increased amounts of fed reactant. CO and ethene were the major reaction products in the gas phase. At high conversions, the condensed liquid contained olefins such as iso-butene and BTX monoaromatics. With increasing amounts of acetol fed, the selectivity to oxygen-free hydrocarbons decreased while the concentration of oxygenated compounds such as ethers, ketones, and furans increased. Simultaneously, coke formation rapidly decreased the weak and strong acid sites of the zeolites. A maximum monoaromatics yield of ∼5 wt.% of fed acetol was achieved in the initial upgrading phase for the purely microporous zeolites with Si/Al = 15 and 29, while mesoporous HZSM-5 showed slightly lower yields of monoaromatics. While the coking propensity increased after introduction of mesopores, all mesoporous catalysts showed an improved capacity for converting acetol compared to their microporous versions. Mesoporous HSZM-5 prepared via desilication of parent HZSM-5 (Si/Al = 15) with a mixture of NaOH and a pore-directing agent showed the highest tolerance towards deactivation, which is attributed to a favorable combination of acid strength and the preservation of crystallinity and microporous volume with well distributed mesopores, improving the accessibility of reactants to active sites. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Catalysis Today is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.cattod.2020.03.041 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 9 StartPage: 301 Subjects: – SubjectFull: Hydroxypropanone Type: general – SubjectFull: Gas phase reactions Type: general – SubjectFull: Silicon alloys Type: general – SubjectFull: Mesoporous materials Type: general – SubjectFull: Catalysts Type: general – SubjectFull: Catalyst poisoning Type: general – SubjectFull: Liquid hydrocarbons Type: general Titles: – TitleFull: Catalytic conversion of acetol over HZSM-5 catalysts – influence of Si/Al ratio and introduction of mesoporosity. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Eschenbacher, Andreas – PersonEntity: Name: NameFull: Andersen, Jakob Afzali – PersonEntity: Name: NameFull: Jensen, Anker Degn IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 04 Text: Apr2021 Type: published Y: 2021 Identifiers: – Type: issn-print Value: 09205861 Numbering: – Type: volume Value: 365 Titles: – TitleFull: Catalysis Today Type: main |
| ResultId | 1 |
