The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Shawn D. Mansfield - One of the best experts on this subject based on the ideXlab platform.
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Chemical Pulping advantages of zip lignin hybrid poplar
Chemsuschem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzalesvigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
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Chemical Pulping Advantages of Zip‐lignin Hybrid Poplar
ChemSusChem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzales-vigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
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significant increases in Pulping efficiency in c4h f5h transformed poplars improved Chemical savings and reduced environmental toxins
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Shannon K Huntley, Dave Ellis, Margarita Gilbert, Clint Chapple, Shawn D. MansfieldAbstract:The gene encoding ferulate 5-hydroxylase (F5H) was overexpressed in poplar (Populus tremula × Populus alba) using the cinnamate-4-hydroxylase (C4H) promoter to drive expression specifically in cells involved in the lignin biosynthetic pathway and was shown to significantly alter the mole percentage of syringyl subunits in the lignin, as determined by thioacidolysis. Analysis of poplar transformed with a C4H-F5H construct demonstrated significant increases in Chemical (kraft) Pulping efficiency from greenhouse-grown trees. Compared to wild-type wood, decreases of 23 kappa units and increases of >20 ISO brightness units were observed in trees exhibiting high syringyl monomer concentrations. These changes were associated with no significant modification in total lignin content and no observed phenotypic differences. C4H-F5H-transformed trees could increase pulp throughputs at mills by >60% while concurrently decreasing Chemicals employed during processing (Chemical Pulping and bleaching) and, consequently, t...
John N Saddler - One of the best experts on this subject based on the ideXlab platform.
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effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam
Biotechnology for Biofuels, 2013Co-Authors: Xuejun Pan, John N SaddlerAbstract:Background Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or Chemical Pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment methods for woody biomass for cellulosic ethanol production, and kraft process is a dominant Chemical Pulping method in paper industry. In the present research, the lignins from organosolv pretreatment and kraft Pulping were evaluated to replace polyol for producing rigid polyurethane foams (RPFs).
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Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam
Biotechnology for Biofuels, 2013Co-Authors: Xuejun Pan, John N SaddlerAbstract:Background Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or Chemical Pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment methods for woody biomass for cellulosic ethanol production, and kraft process is a dominant Chemical Pulping method in paper industry. In the present research, the lignins from organosolv pretreatment and kraft Pulping were evaluated to replace polyol for producing rigid polyurethane foams (RPFs). Results Petroleum-based polyol was replaced with hardwood ethanol organosolv lignin (HEL) or hardwood kraft lignin (HKL) from 25% to 70% (molar percentage) in preparing rigid polyurethane foam. The prepared foams contained 12-36% (w/w) HEL or 9-28% (w/w) HKL. The density, compressive strength, and cellular structure of the prepared foams were investigated and compared. Chain extenders were used to improve the properties of the RPFs. Conclusions It was found that lignin was Chemically crosslinked not just physically trapped in the rigid polyurethane foams. The lignin-containing foams had comparable structure and strength up to 25-30% (w/w) HEL or 19-23% (w/w) HKL addition. The results indicated that HEL performed much better in RPFs and could replace more polyol at the same strength than HKL because the former had a better miscibility with the polyol than the latter. Chain extender such as butanediol could improve the strength of lignin-containing RPFs.
John Ralph - One of the best experts on this subject based on the ideXlab platform.
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Chemical Pulping advantages of zip lignin hybrid poplar
Chemsuschem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzalesvigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
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Chemical Pulping Advantages of Zip‐lignin Hybrid Poplar
ChemSusChem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzales-vigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
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Hydroxycinnamates in lignification
Phytochemistry Reviews, 2009Co-Authors: John RalphAbstract:Hydroxycinnamates incorporate into lignins by various mechanisms. The polysaccharide esters of ferulate, in particular, and the range of dehydrodiferulates and higher oligomers in grasses, participate in free-radical (cross-)coupling reactions during lignification to become integrally bound into the lignin polymer, resulting in extensive cross-linking between lignins and polysaccharides. Monolignol-hydroxycinnamate (primarily monolignol-p-coumarate) conjugates are primary building blocks for lignins, again in grasses (but analogously with monolignol acetates and p-hydroxybenzoates in other plants); radical coupling reactions of the monolignol moiety of the conjugate result in lignins with pendant p-coumarate units acylating a variety of lignin structures. Recent evidence suggests that even the hydroxycinnamic acids themselves can be monomers in lignification in wild-type and transgenic plants, undergoing radical cross-coupling reactions to incorporate into the polymer with interesting consequences. The compatibility of ferulate, in particular, with lignification suggests that plants able to utilize monolignol-ferulate conjugates in their primary monomer supply will be particularly well suited for subsequent Chemical delignification, potentially improving processes for biomass conversion to biofuels, and for Chemical Pulping.
Shengfei Zhou - One of the best experts on this subject based on the ideXlab platform.
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Chemical Pulping advantages of zip lignin hybrid poplar
Chemsuschem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzalesvigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
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Chemical Pulping Advantages of Zip‐lignin Hybrid Poplar
ChemSusChem, 2017Co-Authors: Shengfei Zhou, John Ralph, Troy Runge, Steven D. Karlen, Eliana Gonzales-vigil, Shawn D. MansfieldAbstract:Hybrid poplar genetically engineered to possess Chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance Chemical Pulping efficiencies. Kraft Pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperature and Chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of Pulping were created, and the pulp bleaching and physical properties evaluated. Under identical cooking conditions, compared to wild-type, the zip-lignin hybrid poplar showed extended delignification, confirming the zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for zip-lignin poplar pulp, although differences in residual lignin between zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between Pulping conditions that resulted in identical delignification, with the zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41 % gain). Bleaching and physical properties were subsequently equivalent between the samples with slight Chemical savings realized in the zip-lignin samples due to the enhanced delignification.
Xuejun Pan - One of the best experts on this subject based on the ideXlab platform.
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effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam
Biotechnology for Biofuels, 2013Co-Authors: Xuejun Pan, John N SaddlerAbstract:Background Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or Chemical Pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment methods for woody biomass for cellulosic ethanol production, and kraft process is a dominant Chemical Pulping method in paper industry. In the present research, the lignins from organosolv pretreatment and kraft Pulping were evaluated to replace polyol for producing rigid polyurethane foams (RPFs).
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Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam
Biotechnology for Biofuels, 2013Co-Authors: Xuejun Pan, John N SaddlerAbstract:Background Lignin is one of the three major components in plant cell walls, and it can be isolated (dissolved) from the cell wall in pretreatment or Chemical Pulping. However, there is a lack of high-value applications for lignin, and the commonest proposal for lignin is power and steam generation through combustion. Organosolv ethanol process is one of the effective pretreatment methods for woody biomass for cellulosic ethanol production, and kraft process is a dominant Chemical Pulping method in paper industry. In the present research, the lignins from organosolv pretreatment and kraft Pulping were evaluated to replace polyol for producing rigid polyurethane foams (RPFs). Results Petroleum-based polyol was replaced with hardwood ethanol organosolv lignin (HEL) or hardwood kraft lignin (HKL) from 25% to 70% (molar percentage) in preparing rigid polyurethane foam. The prepared foams contained 12-36% (w/w) HEL or 9-28% (w/w) HKL. The density, compressive strength, and cellular structure of the prepared foams were investigated and compared. Chain extenders were used to improve the properties of the RPFs. Conclusions It was found that lignin was Chemically crosslinked not just physically trapped in the rigid polyurethane foams. The lignin-containing foams had comparable structure and strength up to 25-30% (w/w) HEL or 19-23% (w/w) HKL addition. The results indicated that HEL performed much better in RPFs and could replace more polyol at the same strength than HKL because the former had a better miscibility with the polyol than the latter. Chain extender such as butanediol could improve the strength of lignin-containing RPFs.