Degradation Characteristics of Wood Using Supercritical Alcohols

Poudel, Jeeban; Oh, Sea Cheon

doi:10.3390/en5125038

Cited by 5 publications

(4 citation statements)

References 20 publications

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“…The presented results show that there is a close relationship between the bulk density of porous materials and their mechanical properties (Poudel and Oh 2012). The replacement of petroleum-based polyol by bio-based polyol L 0.5_150 resulted in the lowered volumetric expansion of the reaction mixture during polymerization.…”

Section: Mechanical and Thermal Properties Of Analyzed Polyurethanesmentioning

confidence: 64%

Biopolyols obtained via microwave-assisted liquefaction of lignin: structure, rheological, physical and thermal properties

et al. 2018

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The present study examined the application of polyols obtained via microwave-assisted liquefaction of lignin in the production of rigid polyurethane foam. Lignin was liquefied in crude glycerol and 1,4-butanediol at different temperatures (130-170 °C), without a catalyst and using various biomass concentrations (15 and 30 wt%). The physicochemical properties, process yield, and FTIR-based identification of the obtained polyols were investigated. Under optimal conditions, i.e., a 5-min microwave heating time and a reaction temperature of 150 °C, a polyol characterized by a suitable hydroxyl number of 670 mg KOH/g was obtained with a 93% process yield. Liquefied biopolyol was directly used for the production of rigid polyurethane foams with the addition of polymeric diphenylmethane diisocyanate at the [NCO/OH] ratio of 2:1. Mechanical properties of the obtained foams gradually improved with increasing content of biopolyol. The 5% weight loss temperature (T 5 ) for bio-based foams was higher, respectively 6 and 13 °C compared to the petrochemical foam. Replacement of petrochemical polyether with biopolyols showed the ability to obtain rigid polyurethane foams from lignin and crude glycerol.

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Section: Mechanical and Thermal Properties Of Analyzed Polyurethanesmentioning

confidence: 64%

Biopolyols obtained via microwave-assisted liquefaction of lignin: structure, rheological, physical and thermal properties

et al. 2018

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“…In addition, a complicated purification and separation process is required, which leads to a low yield of biodiesel and high processing costs [6]. The transesterification for biodiesel production via supercritical alcohols has been suggested to overcome the drawbacks related to the homogeneous catalytic process [14][15][16][17].The comparison of the two methods shows that the supercritical method is much simpler and more environmentally friendly. Furthermore, the presence of water and FFA does not affect the yield of biodiesel as transesterification of triglyceride and esterification of FFA take place simultaneously [18].…”

Section: Introductionmentioning

confidence: 99%

Qualitative Analysis of Transesterification of Waste Pig Fat in Supercritical Alcohols

et al. 2017

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Abstract:In this work, the characteristics of waste pig fat degradation using supercritical alcohols have been studied. Comparative analysis of the influence of supercritical methanol and supercritical ethanol as solvents on the transesterification was the primary focus of this research. The experiments were carried out with waste pig fat to alcohol weight ratios of 1:1.5 (molar ratio: 1:40.5 for methanol and 1:28 for ethanol), 1:2.0 (molar ratio: 1:54 for methanol and 1:37.5 for ethanol) and 1:2.5 (molar ratio: 1:67.5 for methanol and 1:47 for ethanol) at transesterification temperatures 250, 270 and 290 • C for holding time 0, 15, 30, 45 and 60 min. Increase in the transesterification and holding time increased the conversion while increase in alcohol amount from 1:1.5 to 1:2.0 and 1:2.5 had minimal effect on the conversion. Further, majority of the ester composition in using SCM as solvent falls in the carbon range of C17:0, C19:1 and C19:2 while that for SCE falls in the carbon range of C18:0, C20:1 and C20:2. Glycerol was only present while using SCM as solvent.

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“…The conversion of biomass, very often wood, into industrially useful compounds can also be performed with the use of supercritical methanol or ethanol (Minami and Saka 2003;Poudel and Oh 2012), subcritical water (Matsunaga et al 2008) or ionic liquids (Maki-Arvela et al 2010). The main reactions occurring during liquefaction are the degradation of biomass ingredients, esterification and polycondensation.…”

Section: Introductionmentioning

confidence: 99%

Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization

et al. 2016

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In this work lignocellulose biomass liquefaction was used to produce biopolyols suitable for the manufacturing of rigid polyurethane foams. In order to better evaluate the mechanism of the process, pure cellulose was applied as a raw material. The effect of time and temperature on the effectiveness of liquefaction and the parameters of resulting biopolyols were characterized. The prepared materials were analyzed in terms of their chemical structure, rheology, thermal and oxidative stability, and basic physical and mechanical properties that are important from the point of view of polyurethane manufacturing. The optimal parameters for the biopolyol production with a 94 % yield were achieved at 150°C for a 6-h reaction duration. The obtained polyols were characterized by the hydroxyl number of 643 mg KOH/g and enhanced thermal and oxidative stability compared to the polyols obtained at lower temperatures, which is associated with the altered mechanism of liquefaction. The results of rheological tests, analyzed with the use of Ostwald-de Waele and Herschel Bulkley models, revealed that the prepared biopolyols can be classified as pseudoplastic fluids with the viscosity values similar to those of commercially available products. Rigid foams obtained via partial substitution of petrochemical polyol with prepared biobased one were characterized by slightly increased apparent density and average cell size comparing to unmodified materials. The best mechanical performance was observed for the sample containing 35 wt% of biopolyol in the polyol mixture, which indicates a synergistic effect between the applied polyols. The applied modification delayed thermal degradation of foams due to changes in thermal decomposition process. In conclusion, the presented work confirms that lignocellulose biomass liquefaction can be successfully applied as a manufacturing method of polyols later used in the production of polyurethanes.

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Degradation Characteristics of Wood Using Supercritical Alcohols

Cited by 5 publications

References 20 publications

Biopolyols obtained via microwave-assisted liquefaction of lignin: structure, rheological, physical and thermal properties

Biopolyols obtained via microwave-assisted liquefaction of lignin: structure, rheological, physical and thermal properties

Qualitative Analysis of Transesterification of Waste Pig Fat in Supercritical Alcohols

Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization

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