Higher Alcohol Synthesis Using K-Doped CoRhMoS2/MWCNT Catalysts: Influence of Pelletization, Particle Size and Incorporation of Binders

Boahene, Philip; Surisetty, Venkateswara Rao; Sammynaiken, Ramaswami; Dalai, Ajay K.

doi:10.1007/s11244-013-0210-3

Cited by 27 publications

(29 citation statements)

References 30 publications

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“…Nonetheless, the decrease in specific surface area as a result of coimpregnation of Co, Mo, and Rh metal precursors on the supports also significantly influenced the homogeneity of dispersed metal species on the surface of the supports, as corroborated by the X-ray powder diffraction analysis. 7,21 Furthermore, a similar trend (as illustrated above) can be observed when the normalized specific BET surface area (NS BET ) of the prepared catalysts were computed Table 1 …”

Section: Resultssupporting

confidence: 70%

“…Also, the peaks occurring at 2θ values of 26.2, 28.3 and 34.8 can be assigned to the presence of K 2 Mo 2 O 7 species in the samples. 21,31 The average MoO 3 crystallite size from the full width at half maximum (FWHM) diffraction profile computed by the Debye-Scherer's equation (L=0.9λ/βcosθ) for both Cats-CNH and OCP f , showed MoO 3 crystallite size in the range 6-10 nm as opposed to 16 nm for the Cat-OCP catalyst; giving an indication that there must have been metal species agglomeration on the latter catalyst due to its lower specific surface area. Nonetheless, all these particle sizes quite favoured the higher alcohols synthesis reaction, though a much lower extent for Cat-OCP.…”

Section: Resultsmentioning

confidence: 99%

“…The synthesis gas mixture was then introduced via mass flow controllers and the higher alcohols synthesis reaction conducted under steady-state at reaction conditions of 300-3400°C, 8.3 MPa (1300 psig), and a gas hourly space velocity (GHSV) of 3.6 m 3 (STP)/ (h kg cat ) over a period of 24 h. The product gas was cooled to 00°C in a cold trap to separate it into gaseous and liquid phases at the reaction pressure. 7,21 The CO conversion and other gaseous products were monitored hourly by venting the exit gas through an online Shimadzu gas chromatograph instrument equipped with an integrated thermal conductivity detector (TCD) via a sampling valve. Using Ar as an internal standard, the CO conversion was calculated and the overall mass balance of the reaction was determined.…”

Section: Catalytic Activitymentioning

confidence: 99%

“…[19][20] The former is characteristic of the extent of disorderliness in the carbon matrix and the latter is due to the C-C stretching modes present in the material. While the G-band indicates the graphitic E2g plane vibration, the D-band is due to the disordered parts such as grain boundaries, 21,36 which is indicative of the A1g plane. It is known that the intensity ratio of the D to G bands (I D /I G ) is generally used to denote the extent of disorderliness present in the graphite layer of carbon material.…”

Section: Raman Spectroscopic Analysismentioning

confidence: 99%

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Syngas Conversion to Higher Alcohols: Application of novel K-Promoted CoRhMo Catalysts Supported over Carbon Nanohorns and its by-Products

Dalai¹

2017

IPCSE

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Abbreviations: HA: higher alcohols; FTS: fischer-tropsch synthesis; OCP: other carbon particles; OMC: ordered mesoporous carbon; FTIR: fourier transform infra-red; TEM: transmission emission microscopy IntroductionGasoline blends with up to 10% ethanol (E10) and higher alcohols are commercially available at gasoline pump stations in the USA, Canada, and some parts of Europe. 1 The production of these alcohols (C 2 and C 2+ ) promises immense potential to replace other additives utilized as octane boosters in automotive fuels. Catalytic conversion of synthesis gas (mainly, CO+H 2 ) to higher alcohols (HA) via the Fischer-Tropsch synthesis (FTS) process has received tremendous interest due to the generation of environmentally benign octane boosters and alternative fuels to supplement the diminishing supply of the world's finite fossil fuel reserves. In this regard, beneficial incentives derived from the use of these alcohols as alternative fuels or alternative fuel components in transportation systems directly tackles global climate issues such as the reduction of greenhouse gas emissions, reduction of toxic emissions, and also the improvement of the overall energy efficiency of internal combustion engines.2 Unlike gasoline and diesel fuels, higher alcohols contain oxygen components that allow gasoline-blended fuels to combust more completely; thereby, increasing the combustion efficiency and reducing air pollution, and can also be renewable resource depending on the origin of syngas feedstock (via biomass gasification). To improve selectivity and activity of these alcohol products, the catalyst metals and supports used for this reaction play a vital role. 3In the catalysis of hydrogenation reactions on heterogeneous surfaces, whereby metal precursors dispersed on a porous support act as catalyst, the support plays a crucial role due to the probable hydrogen spillover effect. 4,5 The atomic hydrogen forming as a result of dissociative adsorption on the metal migrates onto the support (hydrogen spillover); making the chemical reaction proceeds not only on the metal surface but also on the support. 5In general terms, the support acts to: a. Stabilize the active species and promoters. b. Promote hydrogen or oxygen donation or exchange.c. Modify the dispersion, reducibility, and electron-donating or accepting effects of metal particles 6 among others.Nevertheless, the nature of surface acidity or basicity of the support can greatly impact the surface chemistry of the final catalysts. For instance, metal oxide supports such as SiO 2 and Al 2 O 3 have the tendency to favour hydrocarbons formation by suppressing the reaction rate of alcohols as a result of accelerated coke deposition. AbstractThe submerged arc discharge in liquid nitrogen technique was used to synthesize carbon nanohorns (CNHs) using 90A and 34V; generating other carbon by-products at the high temperature (>4000K) plasma zone, herein depicted as: "other carbon particles" (OCP) and "other fine carbon particles" (OCP f ). In the present work, a series of ...

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Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Section: Catalytic Activitymentioning

confidence: 99%

Section: Raman Spectroscopic Analysismentioning

confidence: 99%

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Syngas Conversion to Higher Alcohols: Application of novel K-Promoted CoRhMo Catalysts Supported over Carbon Nanohorns and its by-Products

Dalai¹

2017

IPCSE

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“…34 For carbon materials such as graphite, carbon nanotubes, ordered mesoporous carbons, carbon nanohorns, etc., information such as electronic structure as well as sample imperfections can be derived from spectra obtained from this technique. 21,35 Figures 3A, 3B show the Raman profiles of both the pristine and functionalized supports as well as their corresponding KCoMoRh catalysts. From the Raman spectra, the two distinct peaks in the range of 1340-1350 cm −1 and 1580-1595 cm −1 observed can be attributed to the so called D-and G-bands, respectively.…”

Section: Raman Spectroscopic Analysismentioning

confidence: 99%

Untitled

2017

IPCSE

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Sustainable Aviation Fuel from Syngas through Higher Alcohols

et al. 2022

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The current review critically summarizes recent developments in transformations of syngas to higher alcohols. Although higher alcohols have found applications as fuel additives, detergents and plastics for a long while, transformation of alcohols to jet fuel has attained recent interest due to an urgent need to develop jet fuels from sustainable sources. Fermentation of lignocellulosic‐based sugars to ethanol as a technology does not compete with the food chain supply being thus a potentially acceptable route if economically viable. An alternative method is to gasify biomass to produce syngas, which can further be transformed to higher alcohols through several pathways. Jet fuel range alkanes are obtained from alcohols via oligomerisation, dehydration and hydrogenation. The highest space time yields of higher alcohols of 0.61 g/(gcath) is obtained over a bimetallic copper‐iron catalyst supported on a hierarchical zeolite at 300 °C and 5 MPa. Furthermore, copper‐cobalt and cobalt‐manganese compositions are promising for the direct synthesis of higher alcohols from syngas, where one of the challenges is to suppress formation of alkanes and CO2 and increase selectivity to higher alcohols. From the mechanistic point of view, it has been proposed to use dual‐site catalysts, where one site promotes hydrogenation, while the other site is required for the chain growth. In addition to selection of the optimum reaction conditions and catalyst properties, kinetic modelling, thermodynamics and scale up issues are discussed.

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Higher Alcohol Synthesis Using K-Doped CoRhMoS2/MWCNT Catalysts: Influence of Pelletization, Particle Size and Incorporation of Binders

Cited by 27 publications

References 30 publications

Syngas Conversion to Higher Alcohols: Application of novel K-Promoted CoRhMo Catalysts Supported over Carbon Nanohorns and its by-Products

Syngas Conversion to Higher Alcohols: Application of novel K-Promoted CoRhMo Catalysts Supported over Carbon Nanohorns and its by-Products

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Sustainable Aviation Fuel from Syngas through Higher Alcohols

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