Hydrolysis of esters in subcritical and supercritical water

Krammer, Petra; Vogel, Herbert

doi:10.1016/s0896-8446(99)00032-7

Cited by 230 publications

(138 citation statements)

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“…Some k u and k c values have been reported in the literature for auto-catalyzed hydrolyses (12,(36)(37)(38)(39)(40)(41)(42) . For instance, Krammer and Vogel (12) presented a plot for the hydrolysis of ethyl acetate, which displays a curvature from which A can be assessed by using (11) and the time for consuming half the initial esters.…”

Section: Figurementioning

confidence: 99%

“…The variations of crosslink density in the early period of exposure (and the associated changes of thermo-mechanical properties) are important in aging problems. In addition, knowing the degelation point and the characteristics of the soluble fraction can be very useful in the chemical recycling of polyesters, especially in nearcritical water (11)(12)(13)(14)(15) , or for delignification in paper processing (16)(17)(18) .…”

Section: Introductionmentioning

confidence: 99%

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Crosslink Density Changes during the Hydrolysis of Tridimensional Polyesters

Richaud

Pierre

Coquillat

et al. 2014

Macro Theory & Simulations

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. The hydrolysis of almost ideal networks based on macrodiols (poly(adipate of ethylene glycol)) of average molar mass about 2 kg/mol, with L=18 ester groups per chain has been studied. Tensile testing was used to evaluate the crosslink density through the statistical theory of rubber elasticity at two temperatures and three values of relative humidity. A kinetic model for ester consumption including an autocatalysis term was proposed and combined with two original approaches for modeling the crosslink density changes. This allowed kinetic parameters of hydrolysis to be determined, and very good predictions were obtained for the variations of crosslink density (or elastic modulus) in the three aging conditions considered.The initial curvature of elastic modulus vs. time was predicted positive for weak autocatalysis and negative for strong autocatalysis. The obtained conversion ratio at degelation was found to decrease sharply with the number of esters per elastically active chain.

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Section: Figurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Crosslink Density Changes during the Hydrolysis of Tridimensional Polyesters

Richaud

Pierre

Coquillat

et al. 2014

Macro Theory & Simulations

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“…The lower dielectric constant of subcritical water enables it to dissolve hydrophobic substances, [2][3][4] while the increase in ion product, by up to 3 orders of magnitude, owing to temperature increase renders subcritical water capable of acting as an acid or base catalyst for hydrolysis and degradation. [5][6][7] Thus the use of subcritical water can also be regarded as a potential replacement for environmentally undesirable acid catalysts. On account of these advantages, subcritical water has increasingly received attention for application in chemical and biochemical processes.…”

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confidence: 99%

Degradation Kinetics of Glucuronic Acid in Subcritical Water

Wang

Neoh

Kobayashi

et al. 2010

Bioscience, Biotechnology, and Biochemistry

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“…Hydrothermal treatment breaks the physical and chemical structure in the materials such as cellulose, hemicelluloses, and lignin [10][11][12][13][14] in paper and kimchi, and these biomasses were broken down into smaller and simpler molecules. Table 2 shows the property of raw samples of kimchi and paper and their products after the hydrothermal treatment which were produced at 180…”

Section: Effect Of the Hydrothermal Treatment On The Property Of The mentioning

confidence: 99%

Hydrothermal Upgrading of Korean MSW for Solid Fuel Production: Effect of MSW Composition

2016

Thermochemical Waste Treatment

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In Korea, municipal solid waste (MSW) treatment is conducted by converting wastes into energy resources using the mechanicalbiological treatment (MBT). The small size MSW to be separated from raw MSW by mechanical treatment (MT) is generally treated by biological treatment that consists of high composition of food residue and paper and so forth. In this research, the hydrothermal treatment was applied to treat the surrogate MT residue composed of paper and/or kimchi. It was shown that the hydrothermal treatment increased the calorific value of the surrogate MT residue due to increasing fixed carbon content and decreasing oxygen content and enhanced the dehydration and drying performances of kimchi. Comparing the results of paper and kimchi samples, the calorific value of the treated product from paper was increased more effectively due to its high content of cellulose. Furthermore, the change of the calorific value before and after the hydrothermal treatment of the mixture of paper and kimchi can be well predicted by this change of paper and kimchi only. The hydrothermal treatment can be expected to effectively convert high moisture MT residue into a uniform solid fuel.

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Hydrolysis of esters in subcritical and supercritical water

Cited by 230 publications

References 22 publications

Crosslink Density Changes during the Hydrolysis of Tridimensional Polyesters

Crosslink Density Changes during the Hydrolysis of Tridimensional Polyesters

Degradation Kinetics of Glucuronic Acid in Subcritical Water

Hydrothermal Upgrading of Korean MSW for Solid Fuel Production: Effect of MSW Composition

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