Selective CO methanation catalysts for fuel processing applications

Dagle, Robert A.; Wang, Yong; Xia, Guanguang; Strohm, James J.; Holladay, Jamie D.; Palo, Daniel R.

doi:10.1016/j.apcata.2007.04.015

Cited by 151 publications

(64 citation statements)

References 16 publications

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“…20 (24) [c] , [5] does not take place at our reaction conditions, which are similar to conditions suggested by Manzer et al [18] Importantly, however, we have found that the formation of butyl esters can be achieved with high yields by employing a concentration step (see Supporting Information) to remove at least a portion of the water. Increasing the concentration of LA and H 2 SO 4 results in high yields of levulinates (> 85 %) at short contact times (2 h; entry 2) and allows for quantitative recovery of the sulfuric acid upon contact with water.…”

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confidence: 67%

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Reactive Extraction of Levulinate Esters and Conversion to γ‐Valerolactone for Production of Liquid Fuels

et al. 2011

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Biomass has been identified as a source of renewable carbon for the production of energy, fuels, and chemicals, facilitating a decreased dependence upon petroleum and a global reduction in greenhouse gas emissions. A promising approach for the utilization of lignocellulosic biomass is the controlled reduction of the biomass feedstock's oxygen content, to produce platform chemicals that retain sufficient functionality for upgrading to a variety of end products. In this respect, levulinic acid (LA) has been identified as an attractive platform molecule from which fine chemicals (e.g., d-aminolevulinic acid, diphenolic acid) and fuel additives (e.g., levulinate esters, methyltetrahydrofuran) can be produced.[1] A particularly promising derivative of LA is g-valerolactone (GVL), [2] from which gasoline, jet fuel, and diesel fuel components can be produced. [3][4][5][6] The production of equimolar quantities of levulinic acid and formic acids can be achieved, in good yield, from lignocellulosic biomass [7,8] and cellulose [5] through hydrolysis with dilute sulfuric acid. The hydrolysis of cellulose has been demonstrated through several strategies. For example, treatments that use dilute sulfuric acid, [5] concentrated hydrochloric acid, [9] solid acids, [10] or ionic liquids [11] all yield levulinic and formic acids as degradation products. To date, the preparation of levulinic acid through hydrolysis with dilute sulfuric acid appears to offer the most promising balance of cost, yield, and scalability, although further developments are needed in product recovery and sulfuric acid management. GVL can be obtained through the reduction of levulinic acid over a metal catalyst, preferably by consuming hydrogen generated in situ via the decomposition of formic acid. [12][13][14] However, the production of GVL by catalytic reduction of LA is complicated by the need to separate LA from sulfuric acid, as residual sulfur leads to low catalytic activity and deactivation with time-on-stream. [5,15] Although promising strategies have been demonstrated for the production of GVL from levulinic and formic acids, [16,17] these strategies are carried out without sulfuric acid and its carryover must be addressed. Therefore, the motivation of the present work is to demonstrate improved sulfuric acid management in levulinic acid-centered biorefining. In the present state of the art, H 2 SO 4 is recovered from LA in an energy-intensive process that involves solvent extraction combined with distillation. Herein, we report an improved, synergistic biorefining strategy that does not require the use of external solvents or energy-intensive distillation steps to separate the levulinic and formic acids from H 2 SO 4 , and instead employs reactive extraction, using butene, to produce hydrophobic esters of levulinic and formic acids. Moreover, we show that these esters spontaneously separate from H 2 SO 4 and can be converted to GVL over a dual-catalyst-bed system. As we have shown previously, GVL can be converted to butene and CO 2 by catalytic d...

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confidence: 67%

“…Butene can be converted into liquid fuels by oligomerization reactions. 11 (24) [c] 1 1.5 9 [b] 353 12 6.3 2.3 1. 6 11.3 60 (49) [c] 59 (47) [c] 20 (27) [c]…”

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confidence: 99%

Reactive Extraction of Levulinate Esters and Conversion to γ‐Valerolactone for Production of Liquid Fuels

et al. 2011

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“…More recent studies investigated the influence of the dispersion on the CO methanation reaction under conditions relevant for feed gas purification [10,19,22]. Although the mechanistic understanding is hampered by the fact that these studies were either performed under integral reaction conditions [22], or the CO 2 and CO methanation were investigated separately at different temperatures under differential reaction conditions [10], the results of these studies agree well with the findings of the early studies [13,14,53] and of our present work in the sense that they also observed an increasing activity with increasing particle size and higher Ru loading.…”

Section: Kinetic Measurementsmentioning

confidence: 99%

“…In that mechanism, CO 2 methanation will be inhibited as long as the CO partial pressure is sufficiently high to maintain the reaction inhibiting CO adlayer. Increasing the selectivity and activity of Ru supported catalysts has already been tried in many different ways, including the use of different support materials such as TiO 2 , Al 2 O 3 , SiO 2 [16,19], or of dopants [20,21], or by varying the Ru particle size [22]. In the latter study on Ru/Al 2 O 3 catalysts, the Ru particle sizes were varied between 7.5 and 34 nm, and a decrease in the temperature for maximum methane formation with decreasing particle size was reported.…”

Section: Introductionmentioning

confidence: 99%

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Eckle

Augustin

Anfang³

et al. 2012

Catalysis Today

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We have investigated the methanation of CO and CO 2 over Ru/zeolite catalysts with different Ru loading in semi-realistic reformate gases by in situ X-ray absorption spectroscopy (XAS), in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and kinetic measurements. Increasing the Ru loading causes an increase of the mean particle size from 0.9 nm (2.2 wt.% Ru) to 1.9 nm (5.6 wt.% Ru). At the same time, also the activity for CO methanation increases, while the selectivity for CO methanation, which is constant at 100% for reformate gases with 0.6% CO, decreases at low CO contents. The latter findings are interpreted in terms of a change in the physical effects governing the selectivity for CO methanation with increasing Ru particle size, from an inherently low activity for CO 2 dissociation and subsequent CO ad methanation on very small Ru nanoparticles to a site blocking mechanism on larger Ru nanoparticles. In the latter mechanism, CO 2 methanation is hindered by a reaction inhibiting adlayer of CO at higher CO ad coverages, i.e., at not too low CO concentrations, but facile in the absence of a CO adlayer, at lower CO concentrations in the reaction gas mixture.

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“…Therefore, hydrogen produced in the steam reformer needs to be purified. Though several purification processes are available [16][17][18][19][20][21], catalytic purification was chosen in this work, requiring two additional reactors: low-temperature water-gas shift (LTWGS) and carbon monoxide preferential oxidation (COPROX)…”

Section: Purificationmentioning

confidence: 99%

Hydrogen Production from Bioethanol: Behavior of a Carbon Oxide Preferential Oxidation Catalyst

et al. 2017

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Hydrogen is recognized as a promising green energy source, particularly when used to feed a polymer electrolyte membrane fuel cell (PEMFC). Here, hydrogen was obtained by bioethanol steam reforming with CO and CO 2 as primary sub products. Since the cell anode is extremely sensitive to poisoning with CO, watergas shift (WGS) and carbon oxide preferential oxidation (COPROX) reactors were employed for hydrogen purification. Catalysts prepared by our lab were tested at pilot plant scale in both the reformer and COPROX unit, where different active phase distributions, stoichiometric excess of air, and reaction temperatures were tested. The use of two different COPROX units with intermediate air injection was also considered. The as-prepared catalysts showed good stability and performance.

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Selective CO methanation catalysts for fuel processing applications

Cited by 151 publications

References 16 publications

Reactive Extraction of Levulinate Esters and Conversion to γ‐Valerolactone for Production of Liquid Fuels

Reactive Extraction of Levulinate Esters and Conversion to γ‐Valerolactone for Production of Liquid Fuels

Influence of the catalyst loading on the activity and the CO selectivity of supported Ru catalysts in the selective methanation of CO in CO2 containing feed gases

Hydrogen Production from Bioethanol: Behavior of a Carbon Oxide Preferential Oxidation Catalyst

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