Liquefaction of beech wood in various supercritical alcohols

Yamazaki, J.; Minami, Eiji; Saka, Shiro

doi:10.1007/s10086-005-0798-4

Cited by 110 publications

(57 citation statements)

References 17 publications

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“…Ethanol, on the other hand, can be produced from agricultural biomass via fermentation technology and is easily available in the market at a high purity [43]. Comparative analysis of SCM and SCE in biodiesel production is indispensable considering the similarity in their properties and the merits they can provide compared to the supercritical water and supercritical carbon dioxide [26]. …”

Section: Resultsmentioning

confidence: 99%

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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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Section: Resultsmentioning

confidence: 99%

“…As these alcohols have lower critical temperatures and pressures, they offer milder conditions for reaction. In addition, these alcohols are expected to readily dissolve relatively high molecular weight products from cellulose, hemicelluloses, and lignin because of their low dielectric constants when compared with that of water [26].…”

Section: Introductionmentioning

confidence: 99%

Qualitative Analysis of Transesterification of Waste Pig Fat in Supercritical Alcohols

et al. 2017

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“…Also, methanol being a C1 alcohol could likely also limit its radical scavenging properties thus reducing the efficiency of inhibiting repolymerisation reactions. Yamazaki et al 12 equally observed similarities between beech wood liquefaction in different primary alcohols of chain length C1 to C10 at 350°C. Longer chain alcohols provided faster wood conversion at short reaction times; however, after 30 minutes reaction time all alcohols performed similarly.…”

Section: Effect Of Different Alcohols On Product Yieldsmentioning

confidence: 87%

Solvent consumption in non-catalytic alcohol solvolysis of biorefinery lignin

Nielsen

Jensen

Schandel

et al. 2017

Sustainable Energy Fuels

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a Lignin solvolysis in supercritical alcohols provides a method for producing a deoxygenated liquid bio-oil. Solvent consumption is however inevitable and due to the high cost of alcohols, relative to a bio-oil product, it can hinder commercial viability. In order to investigate the reactions of solvent consumption we studied solvolysis of biorefinery lignin in several primary alcohols. Lignin solvolysis in methanol, ethanol, 1-propanol and 1-butanol performed similarly with respect to bio-oil composition; however, methanol gave much lower bio-oil yield. Solvent consumption increases with reaction temperature for all alcohols and from 10 wt% at 300°C to 35 wt% at 400°C when using ethanol. The mechanism for solvent consumption was found mainly to take place through three different reactions: Direct decomposition to gas through decarbonylation, formation of light condensation products and incorporation of the alcohol into the bio-oil through covalent bonding. Incorporation of the alchohol into the depolymerised oil product by covalent bonding may be a desirable effect which contributes to increased oil yield, inhibition of repolymerisation, reduced oxygen content and elimination of acidity. IntroductionSolvolysis of lignin rich biomass is of growing interest as a process for producing liquid fuels and chemicals. 1, 2 An important issue in such a process is consumption of the solvent, since the cost of solvent may exceed the value of the depolymerised lignin product. Undesired solvent consumption can therefore hinder commercial viability.The mechanisms of solvent consumption in biomass solvolysis reactions are not understood in detail. Alcohols thermally decompose to gasses at elevated temperatures starting already at the supercritical temperature. 3 Even in reactions where the solvent is recognised as being a reactant, and acting as a hydrogen donor, solvent consumption is often an overlooked parameter. 1,2 Reactions in which alcohol solvent is consumed due to reaction with lignin is seen in some studies where the yield of solids and liquid depolymerised lignin species exceed the amount of initially added lignin 4, 5 hence transformation of solvent to biooil must occur. Direct alkylation of depolymerised lignin by ethanol can be described by a mechanism by Zhao et al. 6 , where alcohol radicals facilitate cleavage and resulting in its incorporation in the depolymerised lignin molecule. The alcohol most likely both facilitates lignin polymer cleavage and inhibition of repolymerisation by reaction with reactive radical species formed at elevated temperatures. Barnard investigated the thermal decomposition of ethanol at 576 °C -624 °C and observed significant gas yields and in particular also a brown polymer. 7 Higher alcohol synthesis as described by Guerbet 8, 9 may be responsible for formation of heavier alcohol polymerisation products that will be found in the bio-oil fraction after lignin solvolysis.We previously conducted a parametric study of bio-refinery lignin solvolysis by ethanol assessing the effect of re...

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“…In addition to supercritical water (Sawai et al 2013), supercritical organic solvents including methanol (Saka and Kusdiana 2001;Imahara et al 2009), ethanol (Warabi et al 2004;Yamazaki et al 2006), acetone (Jin et al 2014) and phenol (Mishra and Saka 2011) have been applied to the liquefaction of biomass. In particular, compared with other liquefaction solvents, ethanol is regarded as the most promising for liquefaction, not only because of its high efficiency, but also because of its renewability and the fact that there are numerous sources (Xu and Etcheverry 2008).…”

Section: Introductionmentioning

confidence: 99%

Liquefaction of Fir Sawdust in Supercritical Ethanol with Dissolved Phosphotungstic Acid

ChangWei¹,

Zheng²,

Lv³

et al. 2015

BioResources

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An environmentally benign approach is put forward with the focus on directly liquefying and depolymerizing Cunninghamia lanceolata (Lamb.) Hook. (Chinese fir) sawdust into ethyl levulinate (EL) under supercritical ethanol (scEtOH) conditions by using phosphotungstic acid (PTA) as a catalyst. The effects of parameters such as catalyst dosage, temperature, and reaction time on alcoholysis yield were investigated. The experimental results show that the biomass alcoholysis yield reached 95.35% with 0.5 g PTA as a catalyst at 260 °C for 30 min. Alcoholysis yield and quantitative content of EL depended on the catalyst. The light bio-oil was primarily composed of phenols, aldehydes, ketones, and esters. A high quantitative content of EL up to 20.82% (AR, Relative abundance) was achieved, compared to 0.73% AR when PTA was not added. Hence, scEtOH with dissolved PTA may offer novel media for both chemical reactions and biomass conversion technology as a replacement for environmentally undesirable organic solvents.

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Liquefaction of beech wood in various supercritical alcohols

Cited by 110 publications

References 17 publications

Qualitative Analysis of Transesterification of Waste Pig Fat in Supercritical Alcohols

Qualitative Analysis of Transesterification of Waste Pig Fat in Supercritical Alcohols

Solvent consumption in non-catalytic alcohol solvolysis of biorefinery lignin

Liquefaction of Fir Sawdust in Supercritical Ethanol with Dissolved Phosphotungstic Acid

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