There has been a recent shift in interest in converting not only natural gas and coal derived syngas to Fischer-Tropsch synthesis products, but also converting biomass-derived syngas, as well as syngas derived from coal and biomass mixtures. As such, conventional catalysts based on iron and cobalt may not be suitable without proper development. This is because, while ash, sulfur compounds, traces of metals, halide compounds, and nitrogen-containing chemicals will likely be lower in concentration in syngas derived from mixtures of coal and biomass (i.e., using entrained-flow oxygen-blown gasifier gasification gasification) than solely from coal, other compounds may actually be increased. Of particular concern are compounds containing alkali chemicals like the chlorides of sodium and potassium. In the first year, University of Kentucky Center for Applied Energy Research (UK-CAER) researchers completed a number of tasks aimed at evaluating the sensitivity of cobalt and iron-based Fischer-Tropsch synthesis (FT) catalysts and a commercial iron-chromia high temperature water-gas shift catalyst (WGS) to alkali halides. This included the preparation of large batches of 0.5%Pt-25%Co/Al{sub 2}O{sub 3} and 100Fe: 5.1Si: 3.0K: 2.0Cu (high alpha) catalysts that were split up among the four different entities participating in the overall project; the testing of the catalysts under clean FT and WGS conditions; the testing of the Fe-Cr WGS catalyst under conditions of co-feeding NaCl and KCl; and the construction and start-up of the continuously stirred tank reactors (CSTRs) for poisoning investigations.

Wood gas generator

Fischer–Tropsch process

Water gas

Water-gas shift reaction

10.2172/1002145

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Kinetic Modeling of Secondary Methane Formation and 1‐Olefin Hydrogenation in Fischer–Tropsch Synthesis over a Cobalt Catalyst

International Journal of Chemical Kinetics (2017)

Branislav Todić Wenping Ma Gary Jacobs Nikola M. Nikačević Burtron H. Davis

ABSTRACT A detailed kinetic model of Fischer–Tropsch synthesis (FTS) product formation, including secondary methane formation and 1‐olefin hydrogenation, has been developed. Methane formation in FTS over the cobalt‐based catalyst is well known to be higher‐than‐expected compared to other n ‐paraffin products under typical reaction conditions. A novel model proposes secondary methane formation on a different type of active site, which is not active in forming C 2+ products, to explain this anomalous methane behavior. In addition, a model of secondary 1‐olefin hydrogenation has also been developed. Secondary 1‐olefin hydrogenation is related to secondary methane formation with both reactions happening on the same type of active sites. The model parameters were estimated from experimental data obtained with Co/Re/γ‐Al 2 O 3 catalyst in a slurry‐phase stirred tank reactor over a range of conditions ( T = 478, 493, and 503 K, P = 1.5 and 2.5 MPa, H 2 /CO feed ratio = 1.4 and 2.1, and X CO = 16–62%). The proposed model including secondary methane formation and 1‐olefin hydrogenation is shown to provide an improved quantitative and qualitative prediction of experimentally observed behavior compared to the detailed model with only primary reactions.

Fischer–Tropsch process

10.1002/kin.21133

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Hydrogenation of Carbon Dioxide to Liquid Fuels

Muthu Kumaran Gnanamani Gary Jacobs Venkat Ramana Rao Pendyala Wenping Ma Burtron H. Davis

Methanation

Fischer–Tropsch process

Refining (metallurgy)

Reactivity

Synthetic fuel

Carbon fibers

10.1002/9781118831922.ch4

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Na Promotion of Pt/m-ZrO2 Catalysts for the Steam Reforming of Formaldehyde

Catalysts (2022)

Michela Martinelli Elijah S. Garcia Zahra Rajabi Caleb D. Watson A. Jeremy Kropf

The decomposition selectivity of formaldehyde during steam reforming was explored using unpromoted and sodium promoted Pt/m-ZrO2 catalysts, and the Na content was varied (0.5%Na, 1%Na, 1.8%Na, 2.5%Na, and 5%Na). In situ DRIFTS experiments during temperature programmed reaction in flowing H2O revealed that formaldehyde is adsorbed at reduced defect sites on zirconia, where it is converted to formate species through the addition of labile bridging OH species. Formate species achieve a maximum intensity in the range of 125–175 °C, where only slight changes in intensity are observed. Above this temperature, the formate decomposition reactivity strongly depends on the Na loading, with the optimum loadings being 1.8%Na and 2.5%Na. CO2 temperature programmed desorption results, as well as a greater splitting observed between the formate νasym(OCO) and νsym(OCO) bands in infrared spectroscopy, indicate greater basicity is induced by the presence of Na. This strengthens the interaction between the formate -CO2 functional group and the catalyst surface, weakening the formate C-H bond. A shift in the ν(CH) band of formate to lower wavenumbers was observed by addition of Na, especially at 1.8%Na and higher loadings. This results in enhanced decarboxylation and dehydrogenation of formate, as observed in in situ DRIFTS, temperature-programmed reaction/mass spectrometry experiments of the steam reforming of formaldehyde, and fixed bed reaction tests. For example, 2.5%Na addition of 2.5% increased the CO2 selectivity from 83.5% to 99.5% and the catalysts achieved higher stable conversion at lower temperature than NiO catalysts reported in the open literature. At 5%Na loading, Pt sites were severely blocked, hindering H-transfer.

Sodium formate

Decarboxylation

10.3390/catal12111294

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Citations (3)