Whisker carbon formation in catalytic steam reforming of biomass gasification gas

Kihlman, Johanna; Kaisalo, Noora; Koskinen-Soivi, Mari-Leena; Simell, Pekka; Niemelä, Marita; Lehtonen, Juha

doi:10.1016/j.apcata.2018.07.011

Cited by 13 publications

(18 citation statements)

References 24 publications

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“…The formation of whisker carbon (a.k.a. carbon nanotubes, carbon filaments) was not expected in this study as this form of carbon is inhibited by the H2S as indicated by the literature [9] and our previous studies [27,35]. The nucleation of the first graphitic ring for the whisker is determined to require 6-7 carbon atoms adsorbed on adjacent sites [60], which is incidentally why partial blocking of the sites by sulfur inhibits the formation of the whisker carbon [9,27].…”

Section: Carbon Characterizationmentioning

confidence: 49%

“…Whisker carbon forms only on specific metals-nickel is the most common one to be used in the reforming [9]. It does not appear at all on noble metal catalysts [9,27]. Although the carbon nanotube growth is an undesired side reaction in the type of process presented in this study, the carbon nanotubes can also be a valuable product.…”

Section: Introductionmentioning

confidence: 82%

“…Graphitic carbon can also grow into a carbon nanotube (a.k.a. whisker carbon) between catalyst support and metal particle [9,26], which quickly leads to the mechanical destruction of the catalyst [9,27,28]. Whisker carbon forms only on specific metals-nickel is the most common one to be used in the reforming [9].…”

Section: Introductionmentioning

confidence: 99%

“…Although carbon formation has been widely studied from different aspects (e.g., catalytic reactions, carbon nanotube production, PAH formation, industrial-scale coking problems, and electrochemical synthesis), the variation in test conditions is immense, complicating the direct comparison of the results. Besides our own publications [27,35], the carbon formation in the reforming of tar at or above 700 • C has been studied with various nickel-containing catalysts for biomass pyrolysis volatiles [36][37][38][39][40], toluene model compound [37,38,[41][42][43][44][45][46][47][48][49], phenol model compound [24,50], naphthalene model compound [24,37,40,48,49], benzene model compound [48,49] and 1-methylnaphthalene model compound [51].…”

Section: Introductionmentioning

confidence: 99%

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Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Kihlman

Simell

2022

Catalysts

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Biomass gasification gas contains hydrocarbons that must be converted to CO and H2 prior to the utilization of the gas in a synthesis unit. Autothermal or steam reforming operating with a nickel or noble metal catalyst is a feasible option to treat the gas, but the harsh reaction conditions may lead to the formation of solid carbon. This study discusses the effects of pressure, time-on-stream, and ethylene content on the carbon formation on nickel and rhodium catalysts. The experiments were carried out with laboratory-scale equipment using reaction conditions that were closely simulated after a pilot-scale biomass gasifier. The results indicated that ethylene content above 20,000 vol-ppm and the increased pressure would increase the carbon formation, although there were differences between the rhodium and nickel catalysts. However, carbon formation was significantly more pronounced on the nickel catalyst when the reaction time was increased from 5 h to 144 h. The type of carbon was found to be primarily encapsulating and graphitic. The formation of whisker carbons (also known as carbon nanotubes) was not observed, which is consistent with the literature as the feed gas contained H2S. It was concluded that utilizing a noble metal catalyst as the front layer of the catalyst bed could lower the risk for carbon formation sufficiently to provide stable long-term operation.

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Section: Carbon Characterizationmentioning

confidence: 49%

Section: Introductionmentioning

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Kihlman

Simell

2022

Catalysts

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“…The formation of pyrolytic carbon takes place when the temperature is increased to over 600 • C while whisker carbon is usually produced at 500-600 • C [14,[28][29][30][31][32]. The formation of whisker carbon during biomass steam reforming was studied by Kihlman et al [33]. The authors found that carbon deposition over Ni can be significantly reduced when the catalyst is doped with Ca.…”

Section: Introductionmentioning

confidence: 99%

Toluene Steam Reforming over Ni/CeZrO2—The Influence of Steam to Carbon Ratio and Contact Time on the Catalyst Performance and Carbon Deposition

Łamacz

2022

Catalysts

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The formation of tars during coal or biomass gasification is a serious issue resulting in decreasing efficiency of the process and increased maintenance costs. The decomposition of tars can be conducted via catalytic steam reforming that enriches the produced gas in hydrogen. Nevertheless, the catalyst should be characterized by high activity, stability, and resistance towards carbon deposition. Ceria-zirconia supported nickel (Ni/CeZrO2) is a very good candidate to catalyze tar removal—Ni is an active phase for reforming reactions, while CeZrO2 provides the active sites that play important roles in protecting the catalyst from carbon deposition. Ni/CeZrO2 shows high activity in the steam reforming of model tar compounds. In this paper, its performance in the steam reforming of toluene and carbon deposition is discussed considering the changing parameters of the reaction: the temperature, steam to carbon ratio, and the contact time.

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Catalytic CO₂ Conversion to C1 Chemicals over Single‐Atom Catalysts

Zhang,

Yang,

Liu

et al. 2023

Advanced Energy Materials

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Carbon dioxide, as an abundant and nontoxic C1 resource, can be extensively applied to produce C1 building blocks via direct and indirect routes. On account of the stable electronic structure and high activation energy of CO2, the most challenging problem of CO2 conversion is the rational design of low‐cost and efficient catalysts with attractive performance. Single‐atom catalysts (SACs) with atomically dispersed metal atoms, strong metal–support interaction, and tunable/unsaturated coordination environment offer a potential choice by achieving maximum atomic utilization and lowering the CO2 activation barrier. Furthermore, the geometric and electronic structure of SACs can be easily regulated by tuning the coordination environment of single atoms, which significantly affects their catalytic performance. In this review, therefore, a comprehensive review of thermocatalytic CO2 conversion to C1 chemicals over SACs is presented. Specifically, the physiochemical and electronic properties, synthesis methods, and characterization technologies are introduced. Thereafter, an overview of catalytic performance and mechanism of SACs is described during thermocatalytic CO2 conversion to C1 chemicals. Finally, the main limitations of current studies on CO2 conversion to C1 chemicals over SACs are summarized, and simultaneouslyperspectives on the future are proposed, in order to provide a guidance for decarbonizing the industries and cycling greenhouse gases.

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Whisker carbon formation in catalytic steam reforming of biomass gasification gas

Cited by 13 publications

References 24 publications

Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Toluene Steam Reforming over Ni/CeZrO2—The Influence of Steam to Carbon Ratio and Contact Time on the Catalyst Performance and Carbon Deposition

Catalytic CO₂ Conversion to C1 Chemicals over Single‐Atom Catalysts

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Whisker carbon formation in catalytic steam reforming of biomass gasification gas

Cited by 13 publications

References 24 publications

Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Carbon Formation in the Reforming of Simulated Biomass Gasification Gas on Nickel and Rhodium Catalysts

Toluene Steam Reforming over Ni/CeZrO2—The Influence of Steam to Carbon Ratio and Contact Time on the Catalyst Performance and Carbon Deposition

Catalytic CO2 Conversion to C1 Chemicals over Single‐Atom Catalysts

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Product

Resources

About

Catalytic CO₂ Conversion to C1 Chemicals over Single‐Atom Catalysts