Hot Gas Desulfurization with Zinc Titanate Sorbents in a Fluidized Bed. 1. Determination of Sorbent Particle Conversion Rate Model Parameters

Konttinen, Jukka; Zevenhoven, C.A.P.; Hupa, Mikko

doi:10.1021/ie960686x

Cited by 21 publications

(29 citation statements)

References 13 publications

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“…Since the formed ZnS occupies a larger volume, sulfidation causes a lack of porosity, as evident by the lowering of the BET surface area found in this study. This also causes product-layer diffusion resistance, and several studies have attempted to model these diffusional resistances. The fresh adsorbent had a surface area of 46 m 2 g –1 and spent adsorbents in the range 17–18 m 2 g –1 , Table .…”

Section: Discussionmentioning

confidence: 99%

Desulfurization of Biomass Syngas Using ZnO-Based Adsorbents: Long-Term Hydrogen Sulfide Breakthrough Experiments

et al. 2020

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Dry-bed adsorptive desulfurization of biomass-based syngas with low to medium sulfur content using ZnO was investigated as an alternative to the conventional wet scrubbing processes. The technical feasibility of ZnO-based desulfurization was studied in laboratory-scale H2S breakthrough experiments. The experiments were set up to utilize realistic H2S concentrations from gasification and therefore long breakthrough times. Experiments were performed in a steam-rich model biosyngas in varying conditions. The long-term breakthrough experiments showed apparent ZnO utilization rates between 10 and 50% in the tested conditions, indicating intraparticle mass-transfer resistances partly due to space velocity and particle size constraints as well as the most likely product-layer resistances as evidenced by the large spent adsorbent surface area decrease. An empirical deactivation model to estimate full breakthrough curves was fitted to the laboratory-scale experimental data. Breakthrough experiment in tar-rich syngas was also performed with the conclusion that ZnO performance is not significantly affected by hydrocarbons despite carbon deposition on the particle surfaces.

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Section: Discussionmentioning

confidence: 99%

Desulfurization of Biomass Syngas Using ZnO-Based Adsorbents: Long-Term Hydrogen Sulfide Breakthrough Experiments

et al. 2020

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“…It is generally applied at high temperatures, which limits removal to residual H 2 S concentrations of >10 ppm. 41 , 37 , 42 …”

Section: Resultsmentioning

confidence: 99%

Steel Manufacturing EAF Dust as a Potential Adsorbent for Hydrogen Sulfide Removal

et al. 2022

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Electric arc furnace dust (EAFD) is a high-volume steel manufacturing byproduct with currently limited value-added applications. EAFD contains metal oxides that can react with H 2 S to form stable sulfides. Hence, the valorization potential of EAFD as an adsorbent material for syngas H 2 S removal was investigated. EAFD from European steel plants was characterized and tested in dynamic H 2 S breakthrough tests and benchmarked against a commercial ZnO-based adsorbent. For this, the EAFD was first processed into adsorbents by simple milling and granulation steps. The EAFD samples exhibited sulfur capture capacities at 400 °C and an SV of 17,000 h –1 that correlated with the sample milling times and Zn concentrations. It was verified that only zinc participated in sulfur capture. Yet, both ZnO and the zinc in ZnFe 2 O 4 were found to be active in sulfidation. At higher temperatures (500 and 600 °C), EAFD sample performance drastically improved and even exceeded the reference zinc oxide performance. The high-zinc (48% by mass) EAFD-B sample exhibited the highest tested performance at 500 °C, with a sulfur capture capacity of 234 mg g –1 . The results indicate that sufficiently high-zinc-content EAFD could serve as a viable sulfur capture material.

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“…The contact with coal gas for 5-6 days had no detrimental effect on sorbents' physical or chemical properties. A detailed analysis of the results on experimental testing and modeling of sulfur removal (reaction 1) at different scales are reported earlier (Konttinen et al, 1996(Konttinen et al, , 1997a.…”

Section: Introductionmentioning

confidence: 95%

Modeling of Sulfided Zinc Titanate Regeneration in a Fluidized-Bed Reactor. 2. Scale-Up of the Solid Conversion Model

Konttinen

Zevenhoven

Hupa

1997

Ind. Eng. Chem. Res.

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Hot gas desulfurization with regenerable metal oxide sorbents is an essential part of the simplified integrated gasification combined cycle process which is currently being demonstrated at commercial scale. As part of a sulfur removal process development, Carbona Corporation is developing fluidized-bed reactor models for scale-up. In the first part of this work, the parameters for an uniform conversion model were determined to describe the conversion rate of ZnS regeneration with oxygen. A method using the uniform conversion model for fluidized-bed application is presented in this paper. The apparent activation energy for the global reaction rate constant obtained from pilot-scale fluidized-bed tests is 200-210 kJ/mol. When using these reaction rate constants as inputs of a sensitivity analysis for a large-scale reactor model, in comparison with the rate constants reported earlier, some differences can be observed. The significance of the differences are discussed. It is stated that any zinc sulfate formed in fluidizedbed regeneration at temperatures 500-600°C will decompose, forming SO 2 , at the actual regeneration temperatures of the bed (725-800°C) due to neglible O 2 partial pressure.

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Hot Gas Desulfurization with Zinc Titanate Sorbents in a Fluidized Bed. 1. Determination of Sorbent Particle Conversion Rate Model Parameters

Cited by 21 publications

References 13 publications

Desulfurization of Biomass Syngas Using ZnO-Based Adsorbents: Long-Term Hydrogen Sulfide Breakthrough Experiments

Desulfurization of Biomass Syngas Using ZnO-Based Adsorbents: Long-Term Hydrogen Sulfide Breakthrough Experiments

Steel Manufacturing EAF Dust as a Potential Adsorbent for Hydrogen Sulfide Removal

Modeling of Sulfided Zinc Titanate Regeneration in a Fluidized-Bed Reactor. 2. Scale-Up of the Solid Conversion Model

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