Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

Davis, Brynmor J.; Jacobs, Gary; Ma, Wanhong; Sparks, Dennis E.; Azzam, Khalid; Mohandas, Janet Chakkamadathil; Shafer, Wilson D.; Pendyala, Venkat Ramana Rao

doi:10.2172/1052997

Cited by 10 publications

(24 citation statements)

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“…Details of the iron catalyst preparation can be found elsewhere [6,24]. In brief, a base Fe catalyst 100 Fe/5.1 Si/1.25 K was first prepared using a precipitation method.…”

Section: Iron Catalyst Preparationmentioning

confidence: 99%

“…The BET surface area, BJH pore volume and pore diameter are 107 m 2 /g, 0.154 cm 3 /g-cat and 6 nm, respectively [6,8].…”

Section: Iron Catalyst Preparationmentioning

confidence: 99%

“…Coal-or biomass-derived syngas generally contains a number of impurities such as sulfur compounds (e.g., H 2 S and COS), halide compounds (e.g., NaCl and KCl), nitrogen-containing chemicals (e.g., NH 3 , NO x and HCN), traces of metals (e.g., Hg and Pb), and other compounds (e.g., NaHCO 3 , KHCO 3 , HCl, HF, and HBr) in addition to ash and tars [1][2][3][4][5][6]. These contaminants could behave as catalyst poisons when their concentrations in syngas reach specific limits; thus, they have the potential to significantly decrease catalyst activity and reduce catalyst life.…”

Section: Introductionmentioning

confidence: 99%

“…Promoters such as B, Mn and K were found to greatly improve the resistance of iron catalyst to H 2 S poison, possibly serving as adsorbents for sulfur [14,22,23]. 6 According to the above review, despite a number of sulfur studies (online or offline addition) performed on iron and cobalt based FTS catalysts, the conclusions of sulfur decreasing or increasing iron catalyst activity and sulfur decreasing or changing little the heavier hydrocarbon selectivity have been shown. The mechanism of sulfur poisoning of iron catalysts for FTS, as well as the ability of sulfur to poison iron (i.e., described as the relationship between the number of metal sites (in moles) affected by each mole of sulfur, have not, to date, reached a consensus (e.g., metal/S ratio varied over a wide range of 2-20).…”

Section: Introductionmentioning

confidence: 99%

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Effect of H2S in syngas on the Fischer–Tropsch synthesis performance of a precipitated iron catalyst

Jacobs

Sparks

et al. 2016

Applied Catalysis A: General

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The sulfur limit, the relationship between the sulfur added and the surface Fe atoms lost (Fe/S), and mechanism of sulfur poisoning Fe catalyst were studied using an iron Fischer-Tropsch synthesis (FTS) catalyst (100 Fe/5.1 Si/2.0 Cu/3.0 K). The FTS reaction was carried out at 230-270 o C, 1.3MPa, H 2 /CO = 0.67-0.77 and 30-70% CO conversion using a 1-L slurry phase reactor. The used Fe catalysts were characterized by XRD, Mössbauer spectroscopy and XANES spectroscopy to understand the deactivation mechanism of the Fe based catalyst after adding up to 1 ppm H 2 S in the feed. Co-feeding of 0.1 ppm H 2 S in syngas for 70 h changed very little the activity of the Fe catalyst, but increasing the H 2 S level to 0.2 ppm or above resulted in measurable deactivation of the Fe catalyst over a similar time period. The limit of sulfur level in the syngas feed (sensitivity) was determined to be 50 ppb. Co-feeding of up to 1.0 ppm H 2 S level was found to increase the extents of the secondary reaction of 1-olefins and the water gas shift (WGS) reaction even though the absolute rates were decreased with time. The addition of H 2 S decreased CH 4 selectivity and increased C 5+ selectivities of the Fe catalyst. The Fe/S ratio, which can be used to define the poison ability of sulfur for the iron catalyst, was quantified based on the deactivation data obtained. The Fe/S ratio strongly depended on temperature and decreased

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“…Details of the iron catalyst preparation can be found elsewhere [6,24]. In brief, a base Fe catalyst 100 Fe/5.1 Si/1.25 K was first prepared using a precipitation method.…”

Section: Iron Catalyst Preparationmentioning

confidence: 99%

“…The BET surface area, BJH pore volume and pore diameter are 107 m 2 /g, 0.154 cm 3 /g-cat and 6 nm, respectively [6,8].…”

Section: Iron Catalyst Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of H2S in syngas on the Fischer–Tropsch synthesis performance of a precipitated iron catalyst

Jacobs

Sparks

et al. 2016

Applied Catalysis A: General

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“…Table 21. Further details about the catalyst preparation method can be found elsewhere (Davis, Jacobs et al 2009). Between each step, the catalyst was dried under vacuum in a rotary evaporator at 80 °C and the temperature was slowly increased to 95 °C.…”

Section: Catalyst Preparation and Physical Characterizationmentioning

confidence: 99%

Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

Alptekin

2013

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Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies.We therefore investigated the impact of potential contaminants (H 2 S, NH 3 , HCN, AsH 3 , PH 3 , HCl, NaCl, KCl, AS 3 , NH 4 NO 3 , NH 4 OH, KNO 3 , HBr, HF, and HNO 3 ) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts; ferrochrome-based high-temperature WGS catalyst (HT-WGS, Shiftmax 120™, Süd-Chemie), low-temperature Cu/ZnO-based WGS catalyst (LT-WGS, Shiftmax 230™, Süd-Chemie), and iron-and cobalt-based Fischer-Trospch synthesis catalysts (Fe-FT & Co-FT, UK-CAER). In this project, TDA Research, Inc. collaborated with a team at the University of Kentucky Center for Applied Energy Research (UK-CAER) led by Dr. Burt Davis.We first conducted a detailed thermodynamic analysis. The three primary mechanisms whereby the contaminants may deactivate the catalyst are condensation, deposition, and reaction. AsH 3 , PH 3 , H 2 S, HCl, NH 3 and HCN were found to have a major impact on the Fe-FT catalyst by producing reaction products, while NaCl, KCl and PH 3 produce trace amounts of deposition products.The impact of the contaminants on the activity, selectivity, and deactivation rates (lifetime) of the catalysts was determined in bench-scale tests. Most of the contaminants appeared to adsorb onto (or react with) the HT-and LT-WGS catalysts were they were co-fed with the syngas:  4.5 ppmv AsH 3 or 1 ppmv PH 3 in the syngas impacted the selectivity and CO conversion of both catalysts  H 2 S slowly degraded both WGS catalysts -A binary mixture of H 2 S (60 ppmv) and NH 3 (38 ppmv) impacted the activity of the LT-WGS catalyst, but not the HT-WGS catalyst  Moderate levels of NH 3 (100 ppmv) or HCN (10 ppmv) had no impact  NaCl or KCl had essentially no effect on the HT-WGS catalyst, but the activity of the LT-WGS catalyst decreased very slowly Long-term experiments on the Co-FT catalyst at 260 and 270 °C showed that all of the contaminants impacted it to some extent with the exception of NaCl and HF. Irrespective of its source (e.g., NH 3 , KNO 3 , or HNO 3 ), ammonia suppressed the activity of the Co-FT catalyst to a moderate degree. There was essentially no impact the Fe-FT catalyst when up to 100 ppmw halide compounds (NaCl and KCl), or up to 40 ppmw alkali ...

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Conversion of waste to sustainable aviation fuel via Fischer–Tropsch synthesis: Front‐end design decisions

Sánchez

Link

Chauhan

et al. 2022

Energy Science & Engineering

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Front-end design decisions for a process to produce sustainable aviation turbine fuel from waste materials were presented. The design employs distributed conversion of wastes to oils, which are then transported to a central facility for gasification, syngas cleaning, Fischer-Tropsch synthesis and refining, that is, a spoke-and-hub approach. Different aspects of the front-end design, that is, the steps up to syngas cleaning, were evaluated. The evaluation employed a combination of case studies, calculations, experimental investigations, and literature review. The supply of sustainable aviation fuel (SAF) as a 50:50 mixture of wastederived and petroleum-derived kerosene to meet the demand of an international airport (Pearson, Toronto) was employed as case study. The amount of raw material required made it impractical to make use of only one type of waste. Using the same set of assumptions, it was shown that in terms of cumulative transport distance required, a spoke-and-hub approach was twice as efficient as centralized processing only. Technologies for decentralized production of oils were assessed, and oils produced by pyrolysis and hydrothermal liquefaction (HTL) in pilot-scale and larger facilities were procured and characterized. These oils were within the broader compositional space of pyrolysis oils and HTL oils reported in laboratory studies. The oil compositions were employed to study the impact of oil composition on entrained flow gasification. Thermodynamic equilibrium calculations of pyrolysis and HTL oil entrained flow gasification resulted in H 2 / CO ratios of syngas and O 2 consumption rates in a narrow range, despite the diversity of feeds. At the same time, to produce an equal molar amount of syngas (H 2 + CO), less HTL oil than pyrolysis oil was required as feed. Gas cleaning technologies were reviewed to ascertain types of contaminants anticipated after gasification, their removal effectiveness, and Fischer-Tropsch catalyst poisoning 1763

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Sensitivity of Fischer-Tropsch Synthesis and Water-Gas Shift Catalysts to Poisons from High-Temperature High-Pressure Entrained-Flow (EF) Oxygen-Blown Gasifier Gasification of Coal/Biomass Mixtures

Cited by 10 publications

References 1 publication

Effect of H2S in syngas on the Fischer–Tropsch synthesis performance of a precipitated iron catalyst

Effect of H2S in syngas on the Fischer–Tropsch synthesis performance of a precipitated iron catalyst

Impact of Contaminants Present in Coal-Biomass Derived Synthesis Gas on Water-gas Shift and Fischer-Tropsch Synthesis Catalysts

Conversion of waste to sustainable aviation fuel via Fischer–Tropsch synthesis: Front‐end design decisions

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