The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Michael H Studer - One of the best experts on this subject based on the ideXlab platform.
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two stage steam explosion pretreatment of softwood with 2 Naphthol as carbocation scavenger
Biotechnology for Biofuels, 2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rudolf Von Rohr, Michael H StuderAbstract:Lignocellulosic biomass is considered as a potential source for sustainable biofuels. In the conversion process, a pretreatment step is necessary in order to overcome the biomass recalcitrance and allow for sufficient fermentable sugar yields in enzymatic hydrolysis. Steam explosion is a well known pretreatment method working without additional chemicals and allowing for efficient particle size reduction. However, it is not effective for the pretreatment of softwood and the harsh conditions necessary to achieve a highly digestible cellulose fraction lead to the partial degradation of the hemicellulosic sugars. Previous studies showed that the autohydrolysis pretreatreatment of softwood can benefit from the addition of 2-Naphthol. This carbocation scavenger prevents lignin repolymerisation leading to an enhanced glucose yield in the subsequent enzymatic hydrolysis. In order to prevent the degradation of the hemicellulose, we investigated in this study a two-stage 2-Naphthol steam explosion pretreatment. In the first stage, spruce wood is pretreated at a severity which is optimal for the autocatalytic hydrolysis of the hemicellulose. The hydrolyzate containing the solubilized sugars is withdrawn from the reactor and the remaining solids are pretreated with different amounts of 2-Naphthol in a second stage at a severity that allows for high glucose yields in enzymatic hydrolysis. The pretreated spruce was subjected to enzymatic hydrolysis and to simultaneous saccharification and fermentation (SSF). In the first stage, the maximal yield of hemicellulosic sugars was 47.5% at a pretreatment severity of log $$R_0$$ = 3.75 at 180 °C. In the second stage, a 2-Naphthol dosage of 0.205 mol/mol lignin C9-unit increased the ethanol yield in SSF with a cellulose loading of 1% using the whole second stage pretreatment slurry by 17% from 73.6% for the control without 2-Naphthol to 90.4%. At a higher solid loading corresponding to 5% w/w cellulose, the yields decreased due to higher concentrations of residual 2-Naphthol in the biomass and the pretreatment liquor, but also due to higher concentrations of potential inhibitors like HMF, furfural and acetic acid. Experiments with washed solids, vacuum filtered solids and the whole slurry showed that residual 2-Naphthol can inhibit the fermentation as a single inhibitor but also synergistically together with HMF, furfural and acetic acid. This work shows that a two-stage pretreatment greatly enhances the recovery of hemicellulosic sugars from spruce wood. The presence of 2-Naphthol in the second pretreatment stage can enhance the ethanol yield in SSF of steam explosion pretreated softwood at low cellulose concentrations of 1% w/w. However, with higher solid loadings of 5% w/w cellulose, the ethanol yields were in general lower due to the solid effect and a synergistic inhibition of HMF, furfural, acetic acid with residual 2-Naphthol. The concentration of residual 2-Naphthol tolerated by the yeast decreased with increasing concentrations of HMF, furfural, and acetic acid.
Christophmaximilian Seidel - One of the best experts on this subject based on the ideXlab platform.
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two stage steam explosion pretreatment of softwood with 2 Naphthol as carbocation scavenger
Biotechnology for Biofuels, 2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rudolf Von Rohr, Michael H StuderAbstract:Lignocellulosic biomass is considered as a potential source for sustainable biofuels. In the conversion process, a pretreatment step is necessary in order to overcome the biomass recalcitrance and allow for sufficient fermentable sugar yields in enzymatic hydrolysis. Steam explosion is a well known pretreatment method working without additional chemicals and allowing for efficient particle size reduction. However, it is not effective for the pretreatment of softwood and the harsh conditions necessary to achieve a highly digestible cellulose fraction lead to the partial degradation of the hemicellulosic sugars. Previous studies showed that the autohydrolysis pretreatreatment of softwood can benefit from the addition of 2-Naphthol. This carbocation scavenger prevents lignin repolymerisation leading to an enhanced glucose yield in the subsequent enzymatic hydrolysis. In order to prevent the degradation of the hemicellulose, we investigated in this study a two-stage 2-Naphthol steam explosion pretreatment. In the first stage, spruce wood is pretreated at a severity which is optimal for the autocatalytic hydrolysis of the hemicellulose. The hydrolyzate containing the solubilized sugars is withdrawn from the reactor and the remaining solids are pretreated with different amounts of 2-Naphthol in a second stage at a severity that allows for high glucose yields in enzymatic hydrolysis. The pretreated spruce was subjected to enzymatic hydrolysis and to simultaneous saccharification and fermentation (SSF). In the first stage, the maximal yield of hemicellulosic sugars was 47.5% at a pretreatment severity of log $$R_0$$ = 3.75 at 180 °C. In the second stage, a 2-Naphthol dosage of 0.205 mol/mol lignin C9-unit increased the ethanol yield in SSF with a cellulose loading of 1% using the whole second stage pretreatment slurry by 17% from 73.6% for the control without 2-Naphthol to 90.4%. At a higher solid loading corresponding to 5% w/w cellulose, the yields decreased due to higher concentrations of residual 2-Naphthol in the biomass and the pretreatment liquor, but also due to higher concentrations of potential inhibitors like HMF, furfural and acetic acid. Experiments with washed solids, vacuum filtered solids and the whole slurry showed that residual 2-Naphthol can inhibit the fermentation as a single inhibitor but also synergistically together with HMF, furfural and acetic acid. This work shows that a two-stage pretreatment greatly enhances the recovery of hemicellulosic sugars from spruce wood. The presence of 2-Naphthol in the second pretreatment stage can enhance the ethanol yield in SSF of steam explosion pretreated softwood at low cellulose concentrations of 1% w/w. However, with higher solid loadings of 5% w/w cellulose, the ethanol yields were in general lower due to the solid effect and a synergistic inhibition of HMF, furfural, acetic acid with residual 2-Naphthol. The concentration of residual 2-Naphthol tolerated by the yeast decreased with increasing concentrations of HMF, furfural, and acetic acid.
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MOESM4 of Two-stage steam explosion pretreatment of softwood with 2-Naphthol as carbocation scavenger
2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rohr, Michael StuderAbstract:Additional file 4: Figure S4. Influence of 2-Naphthol dosage on final ethanol concentration in SSF with 5% w/w cellulose
Lanka Satyanarayana - One of the best experts on this subject based on the ideXlab platform.
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oxidative coupling of 2 Naphthol to r s binol by mcm 41 supported mn chiral schiff base complexes
ChemInform, 2015Co-Authors: Kusum K Bania, Galla V Karunakar, Lanka SatyanarayanaAbstract:Enantiopure BINOL is obtained by enantioselective oxidation of 2-Naphthol (I) in the presence of oxygen as oxidant using three Mn(III)-chiral Schiff base complexes supported on MCM-41 as effective reusable catalysts.
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oxidative coupling of 2 Naphthol to r s binol by mcm 41 supported mn chiral schiff base complexes
RSC Advances, 2015Co-Authors: Kusum K Bania, Galla V Karunakar, Lanka SatyanarayanaAbstract:Three Mn(III)-chiral Schiff base complexes supported on MCM-41 are found to be effective reusable catalysts for enantioselective oxidation of 2-Naphthol to (R)- and (S)-BINOL (1,1′ bi-2-Naphthol) in the presence of oxygen. The supported Mn(III)-complexes are characterized by PXRD, FTIR, solid state-NMR, BET, and cyclic voltammetry study. The homo-coupling reaction with oxygen as the oxidant is promoted by 20 mg of Mn(III) Schiff base complexes to afford biNaphthols in nearly quantitative yields with high enantioselectivity of up to 91% ee. The catalytic activities of the homogeneous and heterogeneous chiral catalyst are found to be almost similar. However, the heterogeneous counterparts are found to be advantageous in terms of recyclability and storability. Oxygen partial pressure, the nature of the solvent, temperature and the amount of catalyst affect the catalytic oxidation process. High temperature and highly polar solvent are found to have adverse effects on the catalytic oxidation process.
Laszlo Gyenge - One of the best experts on this subject based on the ideXlab platform.
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two stage steam explosion pretreatment of softwood with 2 Naphthol as carbocation scavenger
Biotechnology for Biofuels, 2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rudolf Von Rohr, Michael H StuderAbstract:Lignocellulosic biomass is considered as a potential source for sustainable biofuels. In the conversion process, a pretreatment step is necessary in order to overcome the biomass recalcitrance and allow for sufficient fermentable sugar yields in enzymatic hydrolysis. Steam explosion is a well known pretreatment method working without additional chemicals and allowing for efficient particle size reduction. However, it is not effective for the pretreatment of softwood and the harsh conditions necessary to achieve a highly digestible cellulose fraction lead to the partial degradation of the hemicellulosic sugars. Previous studies showed that the autohydrolysis pretreatreatment of softwood can benefit from the addition of 2-Naphthol. This carbocation scavenger prevents lignin repolymerisation leading to an enhanced glucose yield in the subsequent enzymatic hydrolysis. In order to prevent the degradation of the hemicellulose, we investigated in this study a two-stage 2-Naphthol steam explosion pretreatment. In the first stage, spruce wood is pretreated at a severity which is optimal for the autocatalytic hydrolysis of the hemicellulose. The hydrolyzate containing the solubilized sugars is withdrawn from the reactor and the remaining solids are pretreated with different amounts of 2-Naphthol in a second stage at a severity that allows for high glucose yields in enzymatic hydrolysis. The pretreated spruce was subjected to enzymatic hydrolysis and to simultaneous saccharification and fermentation (SSF). In the first stage, the maximal yield of hemicellulosic sugars was 47.5% at a pretreatment severity of log $$R_0$$ = 3.75 at 180 °C. In the second stage, a 2-Naphthol dosage of 0.205 mol/mol lignin C9-unit increased the ethanol yield in SSF with a cellulose loading of 1% using the whole second stage pretreatment slurry by 17% from 73.6% for the control without 2-Naphthol to 90.4%. At a higher solid loading corresponding to 5% w/w cellulose, the yields decreased due to higher concentrations of residual 2-Naphthol in the biomass and the pretreatment liquor, but also due to higher concentrations of potential inhibitors like HMF, furfural and acetic acid. Experiments with washed solids, vacuum filtered solids and the whole slurry showed that residual 2-Naphthol can inhibit the fermentation as a single inhibitor but also synergistically together with HMF, furfural and acetic acid. This work shows that a two-stage pretreatment greatly enhances the recovery of hemicellulosic sugars from spruce wood. The presence of 2-Naphthol in the second pretreatment stage can enhance the ethanol yield in SSF of steam explosion pretreated softwood at low cellulose concentrations of 1% w/w. However, with higher solid loadings of 5% w/w cellulose, the ethanol yields were in general lower due to the solid effect and a synergistic inhibition of HMF, furfural, acetic acid with residual 2-Naphthol. The concentration of residual 2-Naphthol tolerated by the yeast decreased with increasing concentrations of HMF, furfural, and acetic acid.
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MOESM4 of Two-stage steam explosion pretreatment of softwood with 2-Naphthol as carbocation scavenger
2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rohr, Michael StuderAbstract:Additional file 4: Figure S4. Influence of 2-Naphthol dosage on final ethanol concentration in SSF with 5% w/w cellulose
Simone Brethauer - One of the best experts on this subject based on the ideXlab platform.
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two stage steam explosion pretreatment of softwood with 2 Naphthol as carbocation scavenger
Biotechnology for Biofuels, 2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rudolf Von Rohr, Michael H StuderAbstract:Lignocellulosic biomass is considered as a potential source for sustainable biofuels. In the conversion process, a pretreatment step is necessary in order to overcome the biomass recalcitrance and allow for sufficient fermentable sugar yields in enzymatic hydrolysis. Steam explosion is a well known pretreatment method working without additional chemicals and allowing for efficient particle size reduction. However, it is not effective for the pretreatment of softwood and the harsh conditions necessary to achieve a highly digestible cellulose fraction lead to the partial degradation of the hemicellulosic sugars. Previous studies showed that the autohydrolysis pretreatreatment of softwood can benefit from the addition of 2-Naphthol. This carbocation scavenger prevents lignin repolymerisation leading to an enhanced glucose yield in the subsequent enzymatic hydrolysis. In order to prevent the degradation of the hemicellulose, we investigated in this study a two-stage 2-Naphthol steam explosion pretreatment. In the first stage, spruce wood is pretreated at a severity which is optimal for the autocatalytic hydrolysis of the hemicellulose. The hydrolyzate containing the solubilized sugars is withdrawn from the reactor and the remaining solids are pretreated with different amounts of 2-Naphthol in a second stage at a severity that allows for high glucose yields in enzymatic hydrolysis. The pretreated spruce was subjected to enzymatic hydrolysis and to simultaneous saccharification and fermentation (SSF). In the first stage, the maximal yield of hemicellulosic sugars was 47.5% at a pretreatment severity of log $$R_0$$ = 3.75 at 180 °C. In the second stage, a 2-Naphthol dosage of 0.205 mol/mol lignin C9-unit increased the ethanol yield in SSF with a cellulose loading of 1% using the whole second stage pretreatment slurry by 17% from 73.6% for the control without 2-Naphthol to 90.4%. At a higher solid loading corresponding to 5% w/w cellulose, the yields decreased due to higher concentrations of residual 2-Naphthol in the biomass and the pretreatment liquor, but also due to higher concentrations of potential inhibitors like HMF, furfural and acetic acid. Experiments with washed solids, vacuum filtered solids and the whole slurry showed that residual 2-Naphthol can inhibit the fermentation as a single inhibitor but also synergistically together with HMF, furfural and acetic acid. This work shows that a two-stage pretreatment greatly enhances the recovery of hemicellulosic sugars from spruce wood. The presence of 2-Naphthol in the second pretreatment stage can enhance the ethanol yield in SSF of steam explosion pretreated softwood at low cellulose concentrations of 1% w/w. However, with higher solid loadings of 5% w/w cellulose, the ethanol yields were in general lower due to the solid effect and a synergistic inhibition of HMF, furfural, acetic acid with residual 2-Naphthol. The concentration of residual 2-Naphthol tolerated by the yeast decreased with increasing concentrations of HMF, furfural, and acetic acid.
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MOESM4 of Two-stage steam explosion pretreatment of softwood with 2-Naphthol as carbocation scavenger
2019Co-Authors: Christophmaximilian Seidel, Simone Brethauer, Laszlo Gyenge, Philipp Rohr, Michael StuderAbstract:Additional file 4: Figure S4. Influence of 2-Naphthol dosage on final ethanol concentration in SSF with 5% w/w cellulose
