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Articles 1 - 30 of 377
Full-Text Articles in Chemical Engineering
Dynamic Model-Based Analysis Of Furfural And Hmf Detoxification By Pure And Mixed Batch Cultures Of S. Cerevisiae And S. Stipitis, Timothy J. Hanly, Michael A. Henson
Dynamic Model-Based Analysis Of Furfural And Hmf Detoxification By Pure And Mixed Batch Cultures Of S. Cerevisiae And S. Stipitis, Timothy J. Hanly, Michael A. Henson
Michael A Henson
Inhibitory compounds that result from biomass hydrolysis are an obstacle to the efficient production of second-generation biofuels. Fermentative microorganisms can reduce compounds such as furfural and 5-hydroxymethyl furfural (HMF), but detoxification is accompanied by reduced growth rates and ethanol yields. In this study, we assess the effects of these furan aldehydes on pure and mixed yeast cultures consisting of a respiratory deficient mutant of Saccharomyces cerevisiae and wild-type Scheffersomyces stipites using dynamic flux balance analysis. Uptake kinetics and stoichiometric equations for the intracellular reduction reactions associated with each inhibitor were added to genome-scale metabolic reconstructions of the two yeasts. Further …
Sans Study Of Highly Resilient Poly(Ethylene Glycol) Hydrogels, Erika M. Saffer, Melissa A. Lackey, David M. Griffin, Suhasini Kishore, Gregory N. Tew, Surita R. Bhatia
Sans Study Of Highly Resilient Poly(Ethylene Glycol) Hydrogels, Erika M. Saffer, Melissa A. Lackey, David M. Griffin, Suhasini Kishore, Gregory N. Tew, Surita R. Bhatia
Gregory N. Tew
Polymer networks are critically important for numerous applications including soft biomaterials, adhesives, coatings, elastomers, and gel-based materials for energy storage. One long-standing challenge these materials present lies in understanding the role of network defects, such as dangling ends and loops, developed during cross-linking. These defects can negatively impact the physical, mechanical, and transport properties of the gel. Here we report chemically cross-linked poly(ethylene glycol) (PEG) gels formed through a unique cross-linking scheme designed to minimize defects in the network. The highly resilient mechanical properties of these systems (discussed in a previous publication) [J. Cui, M. A. Lackey, A. E. Madkour, …
Phosphate Salts Facilitate The Electrospinning Of Hyaluronic Acid Fiber Mats, Eric K. Brenner, Jessica D. Schiffman, Laura J. Toth, Janah C. Szewczyk, Caroline L. Schauer
Phosphate Salts Facilitate The Electrospinning Of Hyaluronic Acid Fiber Mats, Eric K. Brenner, Jessica D. Schiffman, Laura J. Toth, Janah C. Szewczyk, Caroline L. Schauer
Jessica D. Schiffman
Electrospinning is a cost effective and facile method to manufacture fiber mats appropriate for biomedical applications. Due to its high molecular weight and charged backbone, hyaluronic acid (HA) fiber mats with consistent fiber morphology have been difficult to electrospin from neutral pH solutions. Here, we present that the electrospinning of HA fibers in aqueous dimethylformamide solutions is facilitated by the addition of three phosphate salts. The salts—glycerol phosphate (GP), sodium phosphate (SP), and tripolyphosphate (TPP)—facilitated electrospinning of the solutions as characterized by conductivity measurements and fiber morphology. From tensile experiments, HA mats electrospun with SP demonstrated improved Young’s modulus (12 …
Crosslinking Poly(Allylamine) Fibers Electrospun From Basic And Acidic Solutions, Jessica D. Schiffman, Marjorie A. Kiechel, Amalie E. Donius, Ulrike G. K. Wegst, Caroline L. Schauer
Crosslinking Poly(Allylamine) Fibers Electrospun From Basic And Acidic Solutions, Jessica D. Schiffman, Marjorie A. Kiechel, Amalie E. Donius, Ulrike G. K. Wegst, Caroline L. Schauer
Jessica D. Schiffman
Mechanically robust, non-toxic polymer fiber mats are promising materials for a range of biomedical applications; however, further research into enhancing polymer selection is needed. In this study, poly(allylamine) (PAH), an amine-containing polyelectrolyte, was successfully electrospun from aqueous solutions into continuous, cylindrical fibers with a mean diameter of 150 ± 41 nm. A one-step crosslinking method using glutaraldehyde provides insight into the chemical and morphological changes that result from altering the molar ratio of amine to aldehyde groups, whereas a two-step crosslinking method yielded chemically and mechanically robust mats. These results indicate PAH fibrous mats synthesized from aqueous solutions could potentially …
Designing Electrospun Nanofiber Mats To Promote Wound Healing – A Review, Katrina A. Rieger, Nathan P. Birch, Jessica D. Schiffman
Designing Electrospun Nanofiber Mats To Promote Wound Healing – A Review, Katrina A. Rieger, Nathan P. Birch, Jessica D. Schiffman
Jessica D. Schiffman
Current strategies to treat chronic wounds offer limited relief to the 7.75 million patients who suffer from burns or chronic skin ulcers. Thus, as long as chronic wounds remain a global healthcare problem, the development of alternate treatments remain desperately needed. This review explores the recent strategies employed to tailor electrospun nanofiber mats towards accelerating the wound healing process. Porous nanofiber mats readily produced by the electrospinning process offer a promising solution to the management of wounds. The matrix chemistry, surface functionality, and mat degradation rate all can be fine-tuned to govern the interactions that occur at the materials–biology interface. …
Dynamic Metabolic Modeling Of A Microaerobic Yeast Co-Culture: Predicting And Optimizing Ethanol Production From Glucose/Xylose Mixtures, Timothy J. Hanly, Michael A. Henson
Dynamic Metabolic Modeling Of A Microaerobic Yeast Co-Culture: Predicting And Optimizing Ethanol Production From Glucose/Xylose Mixtures, Timothy J. Hanly, Michael A. Henson
Michael A Henson
Background: A key step in any process that converts lignocellulose to biofuels is the efficient fermentation of both hexose and pentose sugars. The co-culture of respiratory-deficient Saccharomyces cerevisiae and wild-type Scheffersomyces stipitis has been identified as a promising system for microaerobic ethanol production because S. cerevisiae only consumes glucose while S. stipitis efficiently converts xylose to ethanol. Results: To better predict how these two yeasts behave in batch co-culture and to optimize system performance, a dynamic flux balance model describing co-culture metabolism was developed from genome-scale metabolic reconstructions of the individual organisms. First a dynamic model was developed for each …
Nanomanufacturing Of Biomaterials, Yoni Engel, Jessica D. Schiffman, Julie M. Goddard, Vincent M. Rotello
Nanomanufacturing Of Biomaterials, Yoni Engel, Jessica D. Schiffman, Julie M. Goddard, Vincent M. Rotello
Jessica D. Schiffman
In this review, we present a few of the many important objectives in the area of biomedical engineering that could open new pathways for nextgeneration biomaterials. We also provide examples of how materials for these goals can be created in an economically viable means through recent advances in high throughput production. These strategies highlight the potential for nanomanufacturing in a variety of areas of importance for human health and safety.
Genome-Based Modeling And Design Of Metabolic Interactions In Microbial Communities, Radhakrishnan Mahadevan, Michael A. Henson
Genome-Based Modeling And Design Of Metabolic Interactions In Microbial Communities, Radhakrishnan Mahadevan, Michael A. Henson
Michael A Henson
Biotechnology research is traditionally focused on individual microbial strains that are perceived to have the necessary metabolic functions, or the capability to have these functions introduced, to achieve a particular task. For many important applications, the development of such omnipotent microbes is an extremely challenging if not impossible task. By contrast, nature employs a radically different strategy based on synergistic combinations of different microbial species that collectively achieve the desired task. These natural communities have evolved to exploit the native metabolic capabilities of each species and are highly adaptive to changes in their environments. However, microbial communities have proven difficult …
Identification And Expression Analysis Of Methyl Jasmonate Responsive Ests In Paclitaxel Producing Taxus Cuspidata Suspension Culture Cells, Sangram K. Lenka, Nadia Boutaoui, Bibin Paulose, Kham Vongpaseuth, Jennifer Normanly, Susan C. Roberts, Elsbeth L. Walker
Identification And Expression Analysis Of Methyl Jasmonate Responsive Ests In Paclitaxel Producing Taxus Cuspidata Suspension Culture Cells, Sangram K. Lenka, Nadia Boutaoui, Bibin Paulose, Kham Vongpaseuth, Jennifer Normanly, Susan C. Roberts, Elsbeth L. Walker
Susan C Roberts
Background Taxol(R)(paclitaxel) promotes microtubule assembly and stabilization and therefore is a potent chemotherapeutic agent against wide range of cancers. Methyl jasmonate (MJ) elicited Taxus cell cultures provide a sustainable option to meet the growing market demand for paclitaxel. Despite its increasing pharmaceutical importance, the molecular genetics of paclitaxel biosynthesis is not fully elucidated. This study focuses on identification of MJ responsive transcripts in cultured Taxus cells using PCR-based suppression subtractive hybridization (SSH) to identify genes involved in global pathway control. Results Six separate SSH cDNA libraries of paclitaxel-accumulating Taxus cuspidata P991 cell lines were constructed at three different post-elicitation time …
A Population Balance Equation Model Of Aggregation Dynamics In Taxus Suspension Cell Cultures, Martin E. Kolewe, Susan C. Roberts, Michael A. Henson
A Population Balance Equation Model Of Aggregation Dynamics In Taxus Suspension Cell Cultures, Martin E. Kolewe, Susan C. Roberts, Michael A. Henson
Michael A Henson
The nature of plant cells to grow as multicellular aggregates in suspension culture has profound effects on bioprocess performance. Recent advances in the measurement of plant cell aggregate size allow for routine process monitoring of this property. We have exploited this capability to develop a conceptual model to describe changes in the aggregate size distribution that are observed over the course of a Taxus cell suspension batch culture. We utilized the population balance equation framework to describe plant cell aggregates as a particulate system, accounting for the relevant phenomenological processes underlying aggregation, such as growth and breakage. We compared model …
Catalytic Fast Pyrolysis Of Wood And Alcohol Mixtures In A Fluidized Bed Reactor, George W. Huber, H. Zhang, T. R. Carlson, R. Xiao
Catalytic Fast Pyrolysis Of Wood And Alcohol Mixtures In A Fluidized Bed Reactor, George W. Huber, H. Zhang, T. R. Carlson, R. Xiao
George W. Huber
Catalytic fast pyrolysis (CFP) of pine wood, alcohols (methanol, 1-propanol, 1-butanol and 2-butanol) and their mixtures with ZSM-5 catalyst were conducted in a bubbling fluidized bed reactor. The effects of temperature and weight hourly space velocity (WHSV) on the product carbon yields and selectivities of CFP of pure pine wood and methanol were investigated. A maximum carbon yield of petrochemicals (aromatics + C2–C4 olefins + C5 compounds) from pine wood of 23.7% was obtained at a temperature of 600 °C and WHSV of 0.35 h−1. A maximum petrochemical yield from methanol of 80.7% was obtained at a temperature of 400 …
Production Of Renewable Aromatic Compounds By Catalytic Fast Pyrolysis Of Lignocellulosic Biomass With Bifunctional Ga/Zsm-5 Catalysts, George W. Huber, Y. Cheng, J. Jae, J. Shi, W. Fan
Production Of Renewable Aromatic Compounds By Catalytic Fast Pyrolysis Of Lignocellulosic Biomass With Bifunctional Ga/Zsm-5 Catalysts, George W. Huber, Y. Cheng, J. Jae, J. Shi, W. Fan
George W. Huber
Heiße Sache! Mit dem neuen difunktionellen Katalysator Ga/ZSM-5 entstehen aromatische Verbindungen bei der schnellen katalytischen Pyrolyse von Biomasse selektiver. Der ZSM-5-Katalysator mit Ga-Promotor wandelt Olefine wie Ethen und Propen, die als Intermediate entstehen, effizienter in Arene (insbesondere Benzol) um. Ga/ZSM-5 vermittelt auch Decarbonylierungen und die Aromatisierung von Olefinen.
Kinetics And Reaction Chemistryifor Slow Pyrolysis Of Enzymatic Hydrolysis Lignin And Organosolv Extracted Lignin Derived From Maplewood, George W. Huber, J. Cho, S. Chu, P. J. Dauenhaue
Kinetics And Reaction Chemistryifor Slow Pyrolysis Of Enzymatic Hydrolysis Lignin And Organosolv Extracted Lignin Derived From Maplewood, George W. Huber, J. Cho, S. Chu, P. J. Dauenhaue
George W. Huber
The kinetics and reaction chemistry for the pyrolysis of Maplewood lignin were investigated using both a pyroprobe reactor and a thermogravimetric analyser mass spectrometry (TGA-MS). Lignin residue after enzymatic hydrolysis and organosolv lignin derived from Maplewood were used to measure the kinetic behaviours of lignin pyrolysis and to analyse pyrolysis product distributions. The enzymatic lignin residue pyrolyzed at lower temperature than that of organosolv lignin. The differential thermogravimetric (DTG) peaks for pyrolysis of the enzymatic residue were more similar to the DTG peaks for pyrolysis of the original Maplewood than DTG of the organosolv lignin. The condensable liquid volatile products …
Kinetics And Reaction Chemistry For Slow Pyrolysis Of Enzymatic Hydrolysis Lignin And Organosolv Extracted Lignin Derived From Maplewood, Paul J. Dauenhauer, J. Cho, S. Chu, G. W. Huber
Kinetics And Reaction Chemistry For Slow Pyrolysis Of Enzymatic Hydrolysis Lignin And Organosolv Extracted Lignin Derived From Maplewood, Paul J. Dauenhauer, J. Cho, S. Chu, G. W. Huber
Paul J. Dauenhauer
The kinetics and reaction chemistry for the pyrolysis of Maplewood lignin were investigated using both a pyroprobe reactor and a thermogravimetric analyser mass spectrometry (TGA-MS). Lignin residue after enzymatic hydrolysis and organosolv lignin derived from Maplewood were used to measure the kinetic behaviours of lignin pyrolysis and to analyse pyrolysis product distributions. The enzymatic lignin residue pyrolyzed at lower temperature than that of organosolv lignin. The differential thermogravimetric (DTG) peaks for pyrolysis of the enzymatic residue were more similar to the DTG peaks for pyrolysis of the original Maplewood than DTG of the organosolv lignin. The condensable liquid volatile products …
Revealing Pyrolysis Chemistry For Biofuels Production: Conversion Of Cellulose To Furans And Small Oxygenates, Paul J. Dauenhauer, M S. Mettler, S. H. Mushrif, A. D. Paulsen, D. G. Vlachos, A. D. Javadekar
Revealing Pyrolysis Chemistry For Biofuels Production: Conversion Of Cellulose To Furans And Small Oxygenates, Paul J. Dauenhauer, M S. Mettler, S. H. Mushrif, A. D. Paulsen, D. G. Vlachos, A. D. Javadekar
Paul J. Dauenhauer
Biomass pyrolysis utilizes high temperatures to produce an economically renewable intermediate (pyrolysis oil) that can be integrated with the existing petroleum infrastructure to produce biofuels. The initial chemical reactions in pyrolysis convert solid biopolymers, such as cellulose (up to 60% of biomass), to a short-lived (less than 0.1 s) liquid phase, which subsequently reacts to produce volatile products. In this work, we develop a novel thin-film pyrolysis technique to overcome typical experimental limitations in biopolymer pyrolysis and identify α-cyclodextrin as an appropriate small-molecule surrogate of cellulose. Ab initio molecular dynamics simulations are performed with this surrogate to reveal the long-debated …
Identification Of Synthetic Host Defense Peptide Mimics That Exert Dual Antimicrobial And Anti-Inflammatory Activities, Nicolás Navasa, Abhigyan Som, Avital Percher, Richard W. Scott, Gregory N. Tew, Juan Anguita
Identification Of Synthetic Host Defense Peptide Mimics That Exert Dual Antimicrobial And Anti-Inflammatory Activities, Nicolás Navasa, Abhigyan Som, Avital Percher, Richard W. Scott, Gregory N. Tew, Juan Anguita
Gregory N. Tew
A group of synthetic antimicrobial oligomers, inspired by naturally occurring antimicrobial peptides, were analyzed for the ability to modulate innate immune responses to Toll-like receptor (TLR) ligands. These synthetic mimics of antimicrobial peptides (SMAMPs) specifically reduced cytokine production in response to Staphylococcus aureus and the S. aureus component lipoteichoic acid (LTA), a TLR2 agonist. Anti-inflammatory SMAMPs prevented the induction of tumor necrosis factor (TNF), interleukin 6 (IL-6), and IL-10 in response to S. aureus or LTA, but no other TLR2 ligands. We show that these SMAMPs bind specifically to LTA in vitro and prevent its interaction with TLR2. Importantly, the …
Anion Mediated Activation Of Guanidine Rich Small Molecules, Abhigyan Som, Yongjiang Xu, Richard W. Scott, Gregory N. Tew
Anion Mediated Activation Of Guanidine Rich Small Molecules, Abhigyan Som, Yongjiang Xu, Richard W. Scott, Gregory N. Tew
Gregory N. Tew
No abstract provided.
A Multicellular Model For Differential Regulation Of Circadian Signals In The Core And Shell Regions Of The Suprachiasmatic Nucleus, Christina Vasalou, Michael A. Henson
A Multicellular Model For Differential Regulation Of Circadian Signals In The Core And Shell Regions Of The Suprachiasmatic Nucleus, Christina Vasalou, Michael A. Henson
Michael A Henson
We developed a multicellular model of the mammalian circadian clock characterized by a high degree of heterogeneity with respect to single cell periodicity and behavior (intrinsic and driven oscillators), neurotransmitter release (VIP, GABA and glutamate synthesis) and spatial organization (core and shell regions), mimicking structural patterns within the SCN associated with distinct circadian functions. We simulated the SCN core and shell separately utilizing experimentally derived connectivity schemes for the two subdivisions as observed within the rat SCN. The core was modeled via a small world network characterized by VIP and GABA colocalization, whereas the shell was simulated as a nearest …
Identification And Thermochemical Analysis Of High-Lignin Feedstocks For Biofuel And Biochemical Production, Venugopal Mendu, Anne E. Harman-Ware, Mark Crocker, Jungho Jae, Jozsef Stork, Samuel Morton, Andrew Placido, George W. Huber, Seth Debolt
Identification And Thermochemical Analysis Of High-Lignin Feedstocks For Biofuel And Biochemical Production, Venugopal Mendu, Anne E. Harman-Ware, Mark Crocker, Jungho Jae, Jozsef Stork, Samuel Morton, Andrew Placido, George W. Huber, Seth Debolt
George W. Huber
Background - Lignin is a highly abundant biopolymer synthesized by plants as a complex component of plant secondary cell walls. Efforts to utilize lignin-based bioproducts are needed. Results - Herein we identify and characterize the composition and pyrolytic deconstruction characteristics of high-lignin feedstocks. Feedstocks displaying the highest levels of lignin were identified as drupe endocarp biomass arising as agricultural waste from horticultural crops. By performing pyrolysis coupled to gas chromatography-mass spectrometry, we characterized lignin-derived deconstruction products from endocarp biomass and compared these with switchgrass. By comparing individual pyrolytic products, we document higher amounts of acetic acid, 1-hydroxy-2-propanone, acetone and furfural …
A Systematic Method To Evaluate And Develop Renewable Energy Technologies, George W. Huber, A. A. Upadhye, W. Qi
A Systematic Method To Evaluate And Develop Renewable Energy Technologies, George W. Huber, A. A. Upadhye, W. Qi
George W. Huber
No abstract provided.
Mechanical Behavior Of Ultra-Low-Dielectric-Constant Mesoporous Amorphous Silica, Dimitrios Maroudas, M. R. Gungor, J. J. Watkins
Mechanical Behavior Of Ultra-Low-Dielectric-Constant Mesoporous Amorphous Silica, Dimitrios Maroudas, M. R. Gungor, J. J. Watkins
Dimitrios Maroudas
We report results for the dependence of the mechanical properties of ordered mesoporous silica structures on the pore diameter based on molecular-dynamics simulations. We examine structures with spherical pores arranged in a simple cubic lattice and cylindrical pores arranged in a square lattice subjected to uniaxial tension and compression; for the structures with cylindrical pores, both radial and axial loading is studied with respect to the pore orientation. Our analysis provides a unifying explanation to the observed mechanical response based on the mechanical loading effects on the pore wall thickness.
Chemistry Of Furan Conversion Into Aromatics And Olefins Over Hzsm-5: A Model Biomass Conversion Reaction, George W. Huber, Y. Cheng
Chemistry Of Furan Conversion Into Aromatics And Olefins Over Hzsm-5: A Model Biomass Conversion Reaction, George W. Huber, Y. Cheng
George W. Huber
The conversion of furan (a model of cellulosic biomass) over HZSM-5 was investigated in a thermogravimetric analysis–mass spectrometry system, in situ Fourier transform infrared analysis, and in a continuous-flow fixed-bed reactor. Furan adsorbed as oligomers at room temperature with a 1.73 of adsorbed furan/Al ratio. These oligomers were polycyclic aromatic compounds that were converted to CO, CO2, aromatics, and olefins at temperatures from 400 to 600 °C. Aromatics (e.g., benzene, toluene, and naphthalene), oligomer isomers (e.g., benzofuran, 2,2-methylenebisfuran, and benzodioxane), and heavy oxygenates (C12+ oligomers) were identified as intermediates formed inside HZSM-5 at different reaction temperatures. During furan conversion, graphite-type …
Catalytic Conversion Of Biomass-Derived Feedstocks Into Olefins And Aromatics With Zsm-5: The Hydrogen To Carbon Effective Ratio, George W. Huber, H. Zhang, Y. Cheng, T. P. Vispute, R. Xiao
Catalytic Conversion Of Biomass-Derived Feedstocks Into Olefins And Aromatics With Zsm-5: The Hydrogen To Carbon Effective Ratio, George W. Huber, H. Zhang, Y. Cheng, T. P. Vispute, R. Xiao
George W. Huber
Catalytic conversion of ten biomass-derived feedstocks, i.e. glucose, sorbitol, glycerol, tetrahydrofuran, methanol and different hydrogenated bio-oil fractions, with different hydrogen to carbon effective (H/Ceff) ratios was conducted in a gas-phase flow fixed-bed reactor with a ZSM-5 catalyst. The aromatic + olefin yield increases and the coke yield decreases with increasing H/Ceff ratio of the feed. There is an inflection point at a H/Ceff ratio = 1.2, where the aromatic + olefin yield does not increase as rapidly as it does prior to this point. The ratio of olefins to aromatics also increases with increasing H/Ceff ratio. CO and CO2 yields …
Analysis Of Aggregate Size As A Process Variable Affecting Paclitaxel Accumulation In Taxus Suspension Cultures, Martin E. Kolewe, Michael A. Henson, Susan C. Roberts
Analysis Of Aggregate Size As A Process Variable Affecting Paclitaxel Accumulation In Taxus Suspension Cultures, Martin E. Kolewe, Michael A. Henson, Susan C. Roberts
Michael A Henson
Plant cell aggregates have long been implicated in affecting cellular metabolism in suspension culture, yet the rigorous characterization of aggregate size as a process variable and its effect on bioprocess performance has not been demonstrated. Aggregate fractionation and analysis of biomass-associated product is commonly used to assess the effect of aggregation, but we establish that this method is flawed under certain conditions and does not necessarily agree with comprehensive studies of total culture performance. Leveraging recent advances to routinely measure aggregate size distributions, we developed a simple method to manipulate aggregate size and evaluate its effect on the culture as …
Modeling Silicic Acid Polymerization Using A Low Coordination Lattice Model, Peter A. Monson, Scott M. Auerbach, Lin Jin
Modeling Silicic Acid Polymerization Using A Low Coordination Lattice Model, Peter A. Monson, Scott M. Auerbach, Lin Jin
Peter A. Monson
We present an atomic lattice model for studying the polymerization of silicic acid in sol-gel and related processes for synthesizing silica materials. Our model is based on Si and O atoms occupying the sites of a body-centered-cubic lattice, with all atoms arranged in SiO4 tetrahedra. This is the simplest model that allows for variation in the Si–O–Si angle, which is largely responsible for the versatility in silica polymorphs. The model describes the assembly of polymerized silica structures starting from a solution of silicic acid in water at a given concentration and pH. This model can simulate related materials—chalcogenides and clays—by …
Simulating Infrared Spectra And Hydrogen Bonding In Cellulose Iβ At Elevated Temperatures, George W. Huber, V. Agarwal, W. C. Conner Jr.
Simulating Infrared Spectra And Hydrogen Bonding In Cellulose Iβ At Elevated Temperatures, George W. Huber, V. Agarwal, W. C. Conner Jr.
George W. Huber
We have modeled the transformation of cellulose Iβ to a high temperature (550 K) structure, which is considered to be the first step in cellulose pyrolysis. We have performed molecular dynamics simulations at constant pressure using the GROMOS 45a4 united atom forcefield. To test the forcefield, we computed the density, thermal expansion coefficient, total dipole moment, and dielectric constant of cellulose Iβ, finding broad agreement with experimental results. We computed infrared (IR) spectra of cellulose Iβ over the range 300–550 K as a probe of hydrogen bonding. Computed IR spectra were found to agree semi-quantitatively with experiment, especially in the …
Production Of Green Aromatics And Olefins By Catalytic Fast Pyrolysis Of Wood Sawdust, George W. Huber, T. R. Carlson, Y. -T Cheng, J Jae
Production Of Green Aromatics And Olefins By Catalytic Fast Pyrolysis Of Wood Sawdust, George W. Huber, T. R. Carlson, Y. -T Cheng, J Jae
George W. Huber
Catalytic fast pyrolysis of pine wood sawdust and furan (a model biomass compound) with ZSM-5 based catalysts was studied with three different reactors: a bench scale bubbling fluidized bed reactor, a fixed bed reactor and a semi-batch pyroprobe reactor. The highest aromatic yield from sawdust of 14% carbon in the fluidized bed reactor was obtained at low biomass weight hourly space velocities (less than 0.5 h−1) and high temperature (600 °C). Olefins (primarily ethylene and propylene) were also produced with a carbon yield of 5.4% carbon. The biomass weight hourly space velocity and the reactor temperature can be used to …
Production Of Furfural And Carboxylic Acids From Waste Aqueous Hemicellulose Solutions From The Pulp And Paper And Cellulosic Ethanol Industries, George W. Huber, R. Xing, W. Qi
Production Of Furfural And Carboxylic Acids From Waste Aqueous Hemicellulose Solutions From The Pulp And Paper And Cellulosic Ethanol Industries, George W. Huber, R. Xing, W. Qi
George W. Huber
In this paper we present a new process to produce furfural and co-products of formic and acetic acids from waste aqueous hemicellulose solutions using a continuous two zone biphasic reactor. We estimate this approach uses 67% to 80% less energy than the current industrial processes to produce furfural. An economic analysis indicates that furfural can be produced with this process at 366 US$ per metric ton which is 25% of the selling price of furfural in the U.S. market today. This analysis assumes a plant capacity of 78 kiloton per year of furfural, 12 kiloton per year of formic acid …
Aerosol Generation By Reactive Boiling Ejection Of Molten Cellulose, Paul J. Dauenhauer, A. R. Teixeira, K. G. Mooney, J. S. Kruger, C. L. Williams, W. J. Suszynski, L. D. Schmidt, D. P. Schmidt
Aerosol Generation By Reactive Boiling Ejection Of Molten Cellulose, Paul J. Dauenhauer, A. R. Teixeira, K. G. Mooney, J. S. Kruger, C. L. Williams, W. J. Suszynski, L. D. Schmidt, D. P. Schmidt
Paul J. Dauenhauer
The generation of primary aerosols from biomass hinders the production of biofuels by pyrolysis, intensifies the environmental impact of forest fires, and exacerbates the health implications associated with cigarette smoking. High speed photography is utilized to elucidate the ejection mechanism of aerosol particles from thermally decomposing cellulose at the timescale of milliseconds. Fluid modeling, based on first principles, and experimental measurement of the ejection phenomenon supports the proposed mechanism of interfacial gas bubble collapse forming a liquid jet which subsequently fragments to form ejected aerosol particles capable of transporting nonvolatile chemicals. Identification of the bubble-collapse/ejection mechanism of intermediate cellulose confirms …
Renewable Gasoline From Aqueous Phase Hydrodeoxygenation Of Aqueous Sugar Solutions Prepared By Hydrolysis Of Maple Wood, George W. Huber, N. Li, G. A. Tompsett, T. Zhang, J. Shi, C. E. Wyman
Renewable Gasoline From Aqueous Phase Hydrodeoxygenation Of Aqueous Sugar Solutions Prepared By Hydrolysis Of Maple Wood, George W. Huber, N. Li, G. A. Tompsett, T. Zhang, J. Shi, C. E. Wyman
George W. Huber
In this paper we demonstrate an integrated process for the production of high octane gasoline from maple wood by hydrolysis of maple wood into aqueous carbohydrate solutions followed by aqueous phase hydrodeoxygenation of the sugar solutions. The aqueous carbohydrate solutions were prepared by both hydrolysis in hot water and hydrolysis with dilute acids (H2SO4, oxalic acid). The aqueous carbohydrate solutions were a mixture of xylose, water soluble hemicellulose oligomers, acetic acid, glucose, glucose oligomers, and probably some lignin polymers. Hydrolysis with hot water produced primarily hemicellulose oligomers whereas hydrolysis with acids produced mainly xylose and acetic acid. The hydrolysis co-product …