The Experts below are selected from a list of 113673 Experts worldwide ranked by ideXlab platform
Linda J Broadbelt - One of the best experts on this subject based on the ideXlab platform.
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A Mechanistic Model of fast pyrolysis of hemicellulose
2018Co-Authors: Xiaowei Zhou, Wenjun Li, Ross Mabon, Linda J BroadbeltAbstract:Hemicellulose is one of the major components of lignocellulosic biomass, which is an abundant source of renewable carbon on the Earth and has potential for the production of renewable drop-in transportation fuels and multiple commodity chemicals. In this work, a structure for hemicellulose extracted from corn stover was proposed to capture the experimentally characterized structural properties. A Mechanistic Model for hemicellulose pyrolysis was constructed based on the reaction family approach that we used for cellulose pyrolysis before. The Model described the decomposition of hemicellulose chains, reactions of intermediates, and formation of a range of low molecular weight products (LMWPs) at the Mechanistic level and specified rate constants for all the reactions in the network. Overall, 504 reactions of 114 species were included in the Mechanistic Model for fast pyrolysis of extracted hemicellulose. The Mechanistic Model closely matched experimental yields of various products with mass yield ≥1 wt%. Modeling results show that both the degree of polymerization and the polydispersity index of hemicellulose have an insignificant effect on the pyrolysis product distribution. Then, the Mechanistic Model of extracted hemicellulose is further extended to simulate the fast pyrolysis of native hemicellulose. Comparison of the Model results showed that fast pyrolysis of native hemicellulose from corn stalk yielded more char, gaseous species, acetol, and much more acetic acid than that of extracted hemicellulose from corn stover, while yielding less 1,2-anhydroxylopyranose, 1,2;3,4-dianhydroxylopyranose and glycolaldehyde.
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 1 experiments and development of a detailed Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Heather B Mayes, Brent H. Shanks, Linda J BroadbeltAbstract:Fast pyrolysis of lignocellulosic biomass, utilizing moderate temperatures ranging from 400 to 600 °C, produces a primary liquid product (pyrolytic bio-oil), which is potentially compatible with existing petroleum-based infrastructure and can be catalytically upgraded to fuels and chemicals. In this work, experiments were conducted with a micropyrolyzer coupled to a gas chromatography–mass spectrometry/flame ionization detector system to investigate fast pyrolysis of neat cellulose and other glucose-based carbohydrates. A detailed Mechanistic Model building on our previous work was developed for fast pyrolysis of neat glucose-based carbohydrates by integrating updated findings obtained through experiments and theoretical calculations. The Model described the decomposition of cellulosic polymer chains, reactions of intermediates, and formation of a range of low molecular weight compounds at the Mechanistic level and specified each elementary reaction step in terms of Arrhenius parameters. The Mechanistic m...
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 2 validation and evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Brent H. Shanks, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose,...
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Experimental and Mechanistic Modeling of Fast Pyrolysis of Neat Glucose-Based Carbohydrates. 2. Validation and Evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Brent H. Shanks, Michael W. Nolte, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose, char, H2O, CO2, CO, and especially glycolaldehyde and 5-hydroxymethylfurfural. The Model was also able to well match the yields of pyrolysis products that our previous Model did not include, such as levoglucosan-furanose, methyl glyoxal, and minor products with yields of less than 1 wt % like levoglucosenone, acetone, dihydroxyacetone, and propenal. The Mechanistic Model showed its versatility in providing insights that were difficult to obtain from experiments, including a time scale of 4–5 s for complete thermoconversion of cellulose at 500 °C. Analysis of the contributions of competing reaction pathways showed that decomposition of cellulosic chains played a more important role in the formation of levoglucosan and glycolaldehyde than in that of other pyrolysis products
Xiaowei Zhou - One of the best experts on this subject based on the ideXlab platform.
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A Mechanistic Model of fast pyrolysis of hemicellulose
2018Co-Authors: Xiaowei Zhou, Wenjun Li, Ross Mabon, Linda J BroadbeltAbstract:Hemicellulose is one of the major components of lignocellulosic biomass, which is an abundant source of renewable carbon on the Earth and has potential for the production of renewable drop-in transportation fuels and multiple commodity chemicals. In this work, a structure for hemicellulose extracted from corn stover was proposed to capture the experimentally characterized structural properties. A Mechanistic Model for hemicellulose pyrolysis was constructed based on the reaction family approach that we used for cellulose pyrolysis before. The Model described the decomposition of hemicellulose chains, reactions of intermediates, and formation of a range of low molecular weight products (LMWPs) at the Mechanistic level and specified rate constants for all the reactions in the network. Overall, 504 reactions of 114 species were included in the Mechanistic Model for fast pyrolysis of extracted hemicellulose. The Mechanistic Model closely matched experimental yields of various products with mass yield ≥1 wt%. Modeling results show that both the degree of polymerization and the polydispersity index of hemicellulose have an insignificant effect on the pyrolysis product distribution. Then, the Mechanistic Model of extracted hemicellulose is further extended to simulate the fast pyrolysis of native hemicellulose. Comparison of the Model results showed that fast pyrolysis of native hemicellulose from corn stalk yielded more char, gaseous species, acetol, and much more acetic acid than that of extracted hemicellulose from corn stover, while yielding less 1,2-anhydroxylopyranose, 1,2;3,4-dianhydroxylopyranose and glycolaldehyde.
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 1 experiments and development of a detailed Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Heather B Mayes, Brent H. Shanks, Linda J BroadbeltAbstract:Fast pyrolysis of lignocellulosic biomass, utilizing moderate temperatures ranging from 400 to 600 °C, produces a primary liquid product (pyrolytic bio-oil), which is potentially compatible with existing petroleum-based infrastructure and can be catalytically upgraded to fuels and chemicals. In this work, experiments were conducted with a micropyrolyzer coupled to a gas chromatography–mass spectrometry/flame ionization detector system to investigate fast pyrolysis of neat cellulose and other glucose-based carbohydrates. A detailed Mechanistic Model building on our previous work was developed for fast pyrolysis of neat glucose-based carbohydrates by integrating updated findings obtained through experiments and theoretical calculations. The Model described the decomposition of cellulosic polymer chains, reactions of intermediates, and formation of a range of low molecular weight compounds at the Mechanistic level and specified each elementary reaction step in terms of Arrhenius parameters. The Mechanistic m...
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 2 validation and evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Brent H. Shanks, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose,...
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Experimental and Mechanistic Modeling of Fast Pyrolysis of Neat Glucose-Based Carbohydrates. 2. Validation and Evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Brent H. Shanks, Michael W. Nolte, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose, char, H2O, CO2, CO, and especially glycolaldehyde and 5-hydroxymethylfurfural. The Model was also able to well match the yields of pyrolysis products that our previous Model did not include, such as levoglucosan-furanose, methyl glyoxal, and minor products with yields of less than 1 wt % like levoglucosenone, acetone, dihydroxyacetone, and propenal. The Mechanistic Model showed its versatility in providing insights that were difficult to obtain from experiments, including a time scale of 4–5 s for complete thermoconversion of cellulose at 500 °C. Analysis of the contributions of competing reaction pathways showed that decomposition of cellulosic chains played a more important role in the formation of levoglucosan and glycolaldehyde than in that of other pyrolysis products
Brent H. Shanks - One of the best experts on this subject based on the ideXlab platform.
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 1 experiments and development of a detailed Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Heather B Mayes, Brent H. Shanks, Linda J BroadbeltAbstract:Fast pyrolysis of lignocellulosic biomass, utilizing moderate temperatures ranging from 400 to 600 °C, produces a primary liquid product (pyrolytic bio-oil), which is potentially compatible with existing petroleum-based infrastructure and can be catalytically upgraded to fuels and chemicals. In this work, experiments were conducted with a micropyrolyzer coupled to a gas chromatography–mass spectrometry/flame ionization detector system to investigate fast pyrolysis of neat cellulose and other glucose-based carbohydrates. A detailed Mechanistic Model building on our previous work was developed for fast pyrolysis of neat glucose-based carbohydrates by integrating updated findings obtained through experiments and theoretical calculations. The Model described the decomposition of cellulosic polymer chains, reactions of intermediates, and formation of a range of low molecular weight compounds at the Mechanistic level and specified each elementary reaction step in terms of Arrhenius parameters. The Mechanistic m...
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 2 validation and evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Brent H. Shanks, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose,...
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Experimental and Mechanistic Modeling of Fast Pyrolysis of Neat Glucose-Based Carbohydrates. 2. Validation and Evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Brent H. Shanks, Michael W. Nolte, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose, char, H2O, CO2, CO, and especially glycolaldehyde and 5-hydroxymethylfurfural. The Model was also able to well match the yields of pyrolysis products that our previous Model did not include, such as levoglucosan-furanose, methyl glyoxal, and minor products with yields of less than 1 wt % like levoglucosenone, acetone, dihydroxyacetone, and propenal. The Mechanistic Model showed its versatility in providing insights that were difficult to obtain from experiments, including a time scale of 4–5 s for complete thermoconversion of cellulose at 500 °C. Analysis of the contributions of competing reaction pathways showed that decomposition of cellulosic chains played a more important role in the formation of levoglucosan and glycolaldehyde than in that of other pyrolysis products
Michael W Nolte - One of the best experts on this subject based on the ideXlab platform.
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 1 experiments and development of a detailed Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Heather B Mayes, Brent H. Shanks, Linda J BroadbeltAbstract:Fast pyrolysis of lignocellulosic biomass, utilizing moderate temperatures ranging from 400 to 600 °C, produces a primary liquid product (pyrolytic bio-oil), which is potentially compatible with existing petroleum-based infrastructure and can be catalytically upgraded to fuels and chemicals. In this work, experiments were conducted with a micropyrolyzer coupled to a gas chromatography–mass spectrometry/flame ionization detector system to investigate fast pyrolysis of neat cellulose and other glucose-based carbohydrates. A detailed Mechanistic Model building on our previous work was developed for fast pyrolysis of neat glucose-based carbohydrates by integrating updated findings obtained through experiments and theoretical calculations. The Model described the decomposition of cellulosic polymer chains, reactions of intermediates, and formation of a range of low molecular weight compounds at the Mechanistic level and specified each elementary reaction step in terms of Arrhenius parameters. The Mechanistic m...
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experimental and Mechanistic Modeling of fast pyrolysis of neat glucose based carbohydrates 2 validation and evaluation of the Mechanistic Model
2014Co-Authors: Xiaowei Zhou, Michael W Nolte, Brent H. Shanks, Linda J BroadbeltAbstract:A computational framework based on continuous distribution kinetics was constructed to solve the Mechanistic Model that was developed for fast pyrolysis of glucose-based carbohydrates in the first part of this study [Zhou et al. Ind. Eng. Chem. Res. 2014, 53. DOI 10.1021/ie502259w]. Comparing Modeling results with experimental yields from fast pyrolysis over a wide range of reaction conditions validates the Model. Agreement between Model yields of final pyrolysis products with experimental data of fast pyrolysis of cellulose at temperatures ranging from 400 to 600 °C and maltohexaose, cellobiose, and glucose at 500 °C showed that the Mechanistic Model was robust and extendable. In comparison to our previous Model [Vinu, R.; Broadbelt, L. J. Energy Environ. Sci. 2012, 5, 9808–9826], the Mechanistic Model presented in this work incorporating new findings from experiments and theoretical calculations showed enhanced performance in capturing experimental yields of major products such as levoglucosan-pyranose,...
Myungchang Kang - One of the best experts on this subject based on the ideXlab platform.
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a Mechanistic Model of cutting force in the micro end milling process
2007Co-Authors: Iksoo Kang, Myungchang KangAbstract:Abstract The analysis of cutting force in micro end milling plays an important role in characterizing the cutting process, as the tool wear and surface texture depending on the cutting force. In this paper, an analytical Mechanistic Model of micro end milling is proposed for predicting the cutting force. The tool–workpiece contact at the flank face is considered in this Model. The cutting force Model which is considering on cutting edge radius of micro tool is simulated and the validity of that is investigated through the newly developed tool dynamometer for micro end milling. The characteristics of cutting force are used for evaluating the tool condition, damaged layer, and surface roughness in micro machining.
