Conversion of Cellulose to Levulinic Acid/Ester over an Acid Catalyst: Impacts of Dispersion of Hydrogen Ions on Polymerization Reactions

Ming, Cong; Sun, Kai; Shao, Yuewen; Zhang, Zhanming; Zhang, Shu; Liu, Qing; Wang, Lele; Hu, Song; Xiang, Jun; Hu, Xun

doi:10.1021/acs.energyfuels.9b02825

Cited by 9 publications

(13 citation statements)

References 46 publications

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“…A binary reaction medium composed of ethanol-glycerol was proposed for the sulfuric acid-catalyzed conversion of glucoseto inhibit the humin formationviathe use of non-aqueous green solvents, but an improvement of the EL yield was not achieved (run EL_3, Table 7) [119]. In addition, the available data for the conversion of C6 carbohydrates to EL with H 2 SO 4 , confirm that cellulose is the most recalcitrant substrate, leading to the lowest EL yields (runs EL_7-EL_8, Table 7), except when higher catalyst concentrations (0.1-0.3 mol/L) were employed (runs EL_9-EL_10, Table 7) and the reaction conditions were properly modulated [69,117,120,121]. Bernardo et al proposed perrhenic acid [72] as strong Brønsted homogeneous acid for the synthesis of EL (runs EL_11-EL_14, Table 7).…”

Section: El Synthesis From Model Carbohydratesmentioning

confidence: 93%

“…Several works have investigated the production of EL from mono-and polysaccharides, preferring the use of diluted sulfuric acid (0.002-0.3 mol/L) (runs EL_1-EL_10, Table 7) [69,[117][118][119][120][121]. Temperatures that are higher than 170 • C and relatively short reaction times (below 2 h) have been generally adopted to achieve good EL yields.…”

Section: El Synthesis From Model Carbohydratesmentioning

confidence: 99%

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Direct Alcoholysis of Carbohydrate Precursors and Real Cellulosic Biomasses to Alkyl Levulinates: A Critical Review

Galletti¹,

Antonetti²,

Fulignati³

et al. 2020

Catalysts

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Alkyl levulinates (ALs) represent outstanding bio-fuels and strategic bio-products within the context of the marketing of levulinic acid derivatives. However, their synthesis by acid-catalyzed esterification of pure levulinic acid, or by acid-catalyzed alcoholysis of furfuryl alcohol, although relatively simple, is still economically disadvantageous, due to the high costs of the pure precursors. The direct one-pot alcoholysis of model C6 carbohydrates and raw biomass represents an alternative approach for the one-step synthesis of ALs. In order to promote the market for these bio-products and, concurrently, the immediate development of new applications, it is necessary to speed up the intensification of their production processes, and this important achievement is onlypossible by using low-cost or, even better, waste biomasses, as starting feedstocks. This review provides an overview of the most recent and promising advances on the one-pot production of ALs from model C6 carbohydrates and real biomasses, in the presence of homogeneous or heterogeneous acid catalysts. The use of model C6 carbohydrates allows for the identification of the best obtainable ALs yields, resulting in being strategic for the development of new smart catalysts, whose chemical properties must be properly tuned, taking into account the involved reaction mechanism. On the other hand, the transition to the real biomass now represents a necessary choice for allowing the next ALs production on a larger scale. The improvement of the available synthetic strategies, the use of raw materials and the development of new applications for ALs will contribute to develop more intensified, greener, and sustainable processes.

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Section: El Synthesis From Model Carbohydratesmentioning

confidence: 93%

Section: El Synthesis From Model Carbohydratesmentioning

confidence: 99%

Direct Alcoholysis of Carbohydrate Precursors and Real Cellulosic Biomasses to Alkyl Levulinates: A Critical Review

Galletti¹,

Antonetti²,

Fulignati³

et al. 2020

Catalysts

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“…Solid nanoparticles may become emulsifiers that replace asphaltenes (which are essentially nanoparticles) , from the interface, and these could be nanocellulose particles that are obtained by various methods from natural cellulose. − Cellulose is the most widespread polymer on earth, being biodegradable, nontoxic, available, and renewable. − The use of cellulose does not a negative impact on the environment, which is being polluted by heavy oil production . In recent years, there has been a growing trend toward obtaining various types of cellulose micro- and nanoparticles, e.g., microfibrillated (also known as nanofibrillated) cellulose, , cellulose nanocrystals, cellulose yarn, microcrystalline cellulose, bacterial cellulose nanoparticles, and biosynthesized fibers .…”

Section: Introductionmentioning

confidence: 99%

Morphology and Rheology of Heavy Crude Oil/Water Emulsions Stabilized by Microfibrillated Cellulose

Gorbacheva

Ilyin

2021

Energy Fuels

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The application of microfibrillated cellulose and sodium dodecyl sulfate (SDS) to obtain heavy crude oil emulsions in water has been considered. First of all, the optimal concentration of cellulose in its aqueous dispersion was studied. A rheological study showed that cellulose dispersions exhibit viscoplasticity when the content of microfibrils is 0.3% or higher. At the same time, these dispersions are capable of flowing under high shear stresses only when the cellulose content does not exceed 1%. The use of 1% cellulose dispersion allows for obtaining stable direct emulsions with oil content up to 30 vol %, while a higher oil concentration leads to the phase inversion with a transition from viscoplasticity of oil-in-water emulsions to almost Newtonian behavior of water-inoil systems. In the case of using SDS, cellulose-free oil emulsions are not resistant to creaming even in a concentrated aqueous SDS solution. The combined application of cellulose microfibrils (1%) and SDS (5%) helps to obtain stable highly concentrated direct emulsions containing up to 80 vol % heavy crude oil. Calculations have shown that the use of 50 vol % emulsion is optimal and allows for reducing energy consumption for transportation of heavy crude oil by 13 times.

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“…For mineral acid such as sulfuric acid (H 2 SO 4 ), the hydrogen ions could be uniformly distributed in the reaction medium such as water. For the solid acid catalyst like the solid acidic resin catalyst, the hydrogen ions are mainly distributed on the local surface of the catalyst but not in whole reaction medium . This creates two potential issues.…”

Section: Introductionmentioning

confidence: 99%

Investigation into Properties of Carbohydrate Polymers Formed from Acid‐Catalyzed Conversion of Sugar Monomers/Oligomers over Brønsted Acid Catalysts

Sun

Zhang

et al. 2020

Energy Tech

Self Cite

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Steric hindrance is an intrinsic issue for solid acid catalysts in catalyzing conversion of sugars with a certain size. Herein, the conversion of furfural and sugar monomers/oligomers over a heterogeneous catalyst (D008) and homogeneous acid (H2SO4) is conducted in aqueous medium. The results indicate the steric hindrance of D008 shows more significant effects on the conversion of the sugars than that of furfural, as the chain form of the sugar monomers/oligomers is much bigger than that of furfural in size. The high local concentration of hydrogen ions on D008 facilitates furfural polymerization via opening of the furan ring through hydration reactions. The deactivation of D008 is responsible for the low yield of volatile products when the polymer formed from the polymerization of the sugars fills the pores. The sugar structures determine the polymer's properties. Thermal stability of the coke derived from the sugar oligomers is lower than that from the sugar monomers due to more aliphatic structures in the resulting coke. In addition, the coke derived from the sugars is more hydrophilic than that from furfural, due to the multiple hydroxyl group in the sugar substrates.

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Conversion of Cellulose to Levulinic Acid/Ester over an Acid Catalyst: Impacts of Dispersion of Hydrogen Ions on Polymerization Reactions

Cited by 9 publications

References 46 publications

Direct Alcoholysis of Carbohydrate Precursors and Real Cellulosic Biomasses to Alkyl Levulinates: A Critical Review

Direct Alcoholysis of Carbohydrate Precursors and Real Cellulosic Biomasses to Alkyl Levulinates: A Critical Review

Morphology and Rheology of Heavy Crude Oil/Water Emulsions Stabilized by Microfibrillated Cellulose

Investigation into Properties of Carbohydrate Polymers Formed from Acid‐Catalyzed Conversion of Sugar Monomers/Oligomers over Brønsted Acid Catalysts

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