Mechanistic study of liquid phase glycerol hydrodeoxygenation with in-situ generated hydrogen

Yfanti, V.-L.; Lemonidou, Angeliki A.

doi:10.1016/j.jcat.2018.09.036

Cited by 46 publications

(43 citation statements)

References 48 publications

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“…It is interesting to point out that no ethylene glycol is formed during acetol hydrogenation suggesting that ethylene glycol is formed due to C-C cleavage of glycerol rather than 1,2-PD or acetol. This result is in agreement with a recent mechanistic study of glycerol hydrogenolysis [31]. Since Ni improves the catalytic activity for acetol hydrogenation and also improves the methanol steam reforming to produce more hydrogen for in situ hydrogenation, the addition of Ni improves the selectivity to 1,2-PD in glycerol hydrogenolysis.…”

Section: X-ray Diffraction and Other Physicochemical Propertiessupporting

confidence: 92%

“…In Figure 9b, it can be seen that the 1,2-PD selectivity is always higher with a higher amount of Ni loaded over the reaction time. One reason that a higher 1,2-PD selectivity can be obtained as the Ni content is increased to 5% is because the acetol concentration in the reaction mixture is lower due to the lower dehydration rate suppressing the formation of other by-products caused by the condensation reactions between acetol and alcohols [31]. As illustrated in Figure 9d, for all types of catalysts, the acetol yields always increase at the early stage of the reaction and then decrease afterward.…”

Section: X-ray Diffraction and Other Physicochemical Propertiesmentioning

confidence: 92%

“…It is interesting to note that professor Lemonidou's group has recently published a few papers on glycerol hydrogenolysis to produce 1,2-PD using in situ hydrogen produced from methanol steam reforming [29][30][31][32][33]. Their initial work compared the activities of Cu/ZnO/Al 2 O 3 and Pt/SiO 2 catalysts [29].…”

Section: Introductionmentioning

confidence: 99%

“…It is generally accepted that the dehydration of glycerol to acetol is the rate determining step in the hydrogenolysis of glycerol to produce 1,2-PD. In order to achieve high selectivity to 1,2-PD, rapid hydrogenation of the acetol intermediate is required as acetol is known to be active to produce other un-desired products via reactions between acetol and alcohols [9,31,34,35]. Thus, a major challenge of the glycerol hydrogenolysis process without adding molecular hydrogen is to ensure a fast hydrogenation of acetol compared to the other side reactions caused by acetol to produce undesired by-products.…”

Section: Introductionmentioning

confidence: 99%

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The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

Liu¹,

Guo²,

Rempel³

et al. 2019

Catalysts

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Production of green chemicals using a biomass derived feedstock is of current interest. Among the processes, the hydrogenolysis of glycerol to 1,2-propanediol (1,2-PD) using externally supplied molecular hydrogen has been studied quite extensively. The utilization of methanol present in crude glycerol from biodiesel production can avoid the additional cost for molecular hydrogen storage and transportation, as well as reduce the safety risks due to the high hydrogen pressure operation. Recently the hydrogenolysis of glycerol with a Cu/ZnO/Al2O3 catalyst using in situ hydrogen generated from methanol steam reforming in a liquid phase reaction has been reported. This paper focusses on the effect of added Ni on the activity of a Cu/ZnO/Al2O3 catalyst prepared by an oxalate gel-co-precipitation method for the hydrogenolysis of glycerol using methanol as a hydrogen source. It is found that Ni reduces the conversion of glycerol but improves the selectivity to 1,2-PD, while a higher conversion of methanol is observed. The promoting effect of Ni on the selectivity to 1,2-PD is attributed to the slower dehydration of glycerol to acetol coupled with a higher availability of in situ hydrogen produced from methanol steam reforming and the higher hydrogenation activity of Ni towards the intermediate acetol to produce 1,2-PD.

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Section: X-ray Diffraction and Other Physicochemical Propertiessupporting

confidence: 92%

Section: X-ray Diffraction and Other Physicochemical Propertiesmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

Liu¹,

Guo²,

Rempel³

et al. 2019

Catalysts

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“…It is not clear when C−C cleavage occurs in this reaction pathway, however, acetaldehyde, ethanol, ethylene, ethane, CO, CO 2 , methanol, formaldehyde, and methane are all observed. C−C cleavage may occur through hydrogenolysis of glycerol to form ethylene glycol or 2‐hydroxyacetaldehyde [35–36] . At short contact times, the major observed C 2 product was acetaldehyde with low yields of hydroxyacetaldehyde observed in some samples.…”

Section: Resultsmentioning

confidence: 99%

The Hydrodeoxygenation of Glycerol over NiMoS_x: Catalyst Stability and Activity at Hydropyrolysis Conditions

et al. 2020

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Catalytic activity tests were run to elucidate the chemistry and catalyst stability for the hydrodeoxygenation of glycerol and other aliphatic oxygenates over a NiMoSx/Al2O3 catalyst at different pretreatments at hydropyrolysis conditions in a continuous flow reactor. Reactivity metrics were developed to quantify and compare the reactivity of NiMo for deoxygenation, hydrogenation, and C−C cleavage. Activity experiments showed sulfided NiMo and reduced NiMo catalysts had similar deoxygenation and hydrogenation activity for glycerol HDO at 400 °C and 270 psig H2 with the NiMoSx catalyst showing higher C−C cleavage activity. Without a sulfur co‐feed, both the NiMoSx and NiMoOx catalysts lost >40 % deoxygenation activity over 30 h time on stream. With a 2100 ppm H2S co‐feed the NiMoSx catalyst showed a 12 times decrease in the deactivation rate for deoxygenation and 6 time decrease in the deactivation rate for hydrogenation. The main products at high conversion were propylene, propane, ethylene, methane, CO, methanol, ethanol, and 1‐propanol. At low conversion, the major products were unsaturated allyl alcohol, acrolein, hydroxyacetone, and acetaldehyde. With no H2S co‐feed at short contact times, there was a significant amount of carbon loss possibly due to condensation reactions, while at 2100 ppm H2S in the feed, the carbon balance was 102.4 %. Temperature programmed oxidation of the spent NiMoSx catalysts after 30 h of glycerol HDO without an H2S co‐feed showed that one of the causes of deactivation was coking.

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Liquid Organic Hydrogen Carriers (LOHCs) as H‐Source for Bio‐Derived Fuels and Additives Production

Valentini

Marrocchi

Vaccaro

2022

Advanced Energy Materials

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consumption combined with a resource efficient circular economy approach, with the final goal of minimizing the impact of health, safety, security and environment.In the design of a greener future, the replacement of depleting sources with renewable ones is at the center of a sustainable development. [2] Biomass is a natural, abundant, renewable, carbon-neutral source; its use represents a promising strategy to address the need for substituting fossil feedstock in the preparation of chemicals, fuels, and materials, besides energy production. [3][4][5][6][7][8][9][10][11][12][13][14] The major issues that limit the large-scale utilization of biomass in fuel production are the differences in cost and process efficiencies compared to those for fossil fuels. [15] After the Covid-19 crisis, this aspect has become even more evident, as reported by the International Agency of Energy, ultimately causing the first contraction in biofuel production over the past two decades. [16] The reduced transport fuel demand and the decreased petroleum-based fuel prices have transitorily lowered the economic interest for biofuel production. In this pandemic and emergency scenario, therefore, has emerged even more clearly the importance of developing efficient strategies for biomass conversion into fuels, making economically attractive the use of environmentally friendly renewable energy systems (Figure 1). [17] Among the plethora of biomass transformations, hydrogenation and hydrodeoxygenation reactions are widely used for decreasing the oxygen content of biomass-derived platforms to increase their potential as fuels. [18][19][20] In this context, as well as in the challenging goal of creating a decarbonized energy system, hydrogen plays a prominent role in the chemical industry. [21][22][23][24] It is important to notice that the vast majority of the worldwide hydrogen production (45-65 Mt/year) features a significant CO 2 footprint as a consequence of different hydrocarbon reforming processes (i.e., steam-reforming of fossil fuels, thermal cracking of natural gas, solar-thermal reforming of methane) or of coal gasification. [25] Several efforts have been directed during the past years toward the definition of possible effective approaches to a green H 2 production by water splitting. [26][27][28][29][30][31] To date, however, both water electrolysis and photo-driven water splitting are economically and energetically unfavorable, with a long way ahead to hold the promise of a zero-carbon energy system. Indeed, the associated energy demand as well as the low market prices of oxygen, inevitably co-produced from water electrolysis, hinder the shaping of a large-scale employment of this technology.Liquid organic hydrogen carriers (LOHCs) are attractive materials for their ability to generate in situ hydrogen that may be directly used to produce target biofuel precursors, fuels or fuel additives. Indeed, the replacement of fossil feedstock is an urgent necessity for shifting toward a carbon neutral energy economy. Several desired chemica...

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Mechanistic study of liquid phase glycerol hydrodeoxygenation with in-situ generated hydrogen

Cited by 46 publications

References 48 publications

The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

The Hydrodeoxygenation of Glycerol over NiMoS_x: Catalyst Stability and Activity at Hydropyrolysis Conditions

Liquid Organic Hydrogen Carriers (LOHCs) as H‐Source for Bio‐Derived Fuels and Additives Production

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Mechanistic study of liquid phase glycerol hydrodeoxygenation with in-situ generated hydrogen

Cited by 46 publications

References 48 publications

The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

The Promoting Effect of Ni on Glycerol Hydrogenolysis to 1,2-Propanediol with In Situ Hydrogen from Methanol Steam Reforming Using a Cu/ZnO/Al2O3 Catalyst

The Hydrodeoxygenation of Glycerol over NiMoSx: Catalyst Stability and Activity at Hydropyrolysis Conditions

Liquid Organic Hydrogen Carriers (LOHCs) as H‐Source for Bio‐Derived Fuels and Additives Production

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The Hydrodeoxygenation of Glycerol over NiMoS_x: Catalyst Stability and Activity at Hydropyrolysis Conditions