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Full-Text Articles in Chemical Engineering
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 …
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 …
Improved Utilization Of Biomass-Derived Carbon By Millisecond Co-Processing With Hydrogen Rich Feedstocks, Paul J. Dauenhauer, J. L. Colby, A. Bhan, L. D. Schmitt
Improved Utilization Of Biomass-Derived Carbon By Millisecond Co-Processing With Hydrogen Rich Feedstocks, Paul J. Dauenhauer, J. L. Colby, A. Bhan, L. D. Schmitt
Paul J. Dauenhauer
A reactor capable of improving the utilization of biomass-derived carbon during thermochemical conversion to synthesis gas is demonstrated experimentally. By co-processing hydrogen-deficient biomass (H/C[similar]2) with hydrogen-rich feedstocks (H/C≥4) through catalytic partial oxidation, 100% of the fuel carbon atoms fed to the reactor can be converted to CO.
Reactive Boiling Of Cellulose For Integrated Catalysis Through A Liquid Intermediate, Paul J. Dauenhauer, J. L. Colby, C. M. Balonek, W. J. Wieslaw, L. D. Schmidt
Reactive Boiling Of Cellulose For Integrated Catalysis Through A Liquid Intermediate, Paul J. Dauenhauer, J. L. Colby, C. M. Balonek, W. J. Wieslaw, L. D. Schmidt
Paul J. Dauenhauer
Advanced biomass processing technology integrating fast pyrolysis and inorganic catalysis requires an improved understanding of the thermal decomposition of biopolymers in contact with porous catalytic surfaces. High speed photography (1000 frames per second) reveals that direct impingement of microcrystalline cellulose particles (300 μm) with rhodium-based reforming catalysts at high temperature (700 °C) produces an intermediate liquid phase that reactively boils to vapors. The intermediate liquid maintains contact with the porous surface permitting high heat transfer (MW m−2) generating an internal thermal gradient visible within the particle as a propagating wave of solid to liquid conversion. Complete conversion to liquid yields …
Millisecond Autothermal Steam Reforming Of Cellulose For Synthetic Biofuels By Reactive Flash Volatilization, Paul J. Dauenhauer, Lanny D. Schmidt, Joshua L. Colby
Millisecond Autothermal Steam Reforming Of Cellulose For Synthetic Biofuels By Reactive Flash Volatilization, Paul J. Dauenhauer, Lanny D. Schmidt, Joshua L. Colby
Paul J. Dauenhauer
Three biomass-to-liquid process steps (volatilization of cellulose, tar-cleaning of organic products, and water-gas-shift of the gaseous effluent) have been integrated into a single autothermal catalytic reactor for the production of high quality synthesis gas at millisecond residence times ([similar]30 ms). Particles of cellulose ([similar]300 μm) were directly impinged upon the hot, catalytic bed of Rh–Ce/γ-Al2O3 catalyst on 1.3 mm α-Al2O3 spheres in the presence of O2, N2, and steam in a continuous flow fixed-bed reactor at 500–1100 °C. Complete conversion to gases was observed for all experimental parameters including N2/O2, S/C, the total flow rate of cellulose, and the fuel-to-oxygen …