An Engineering Analysis of the Production of Xylose by Dilute Acid Hydrolysis of Hardwood Hemicellulose


  • Mark T. Maloney,

    1. University of Wisconsin-Madison, Madison, WI 53706
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    • Mark T. Maloney earned his B.S. in Chemical Engineering, at the University of Illinois and is currently completing his Ph.D. studies at the University of Wisconsin-Madison. He also has worked as a design engineer for Monsanto Company and as a co-op engineer for Amoco Chemicals Corporation. His research interests are in reaction engineering and separation processes.

  • Thomas W. Chapman,

    1. University of Wisconsin-Madison, Madison, WI 53706
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    • Thomas W. Chapman is Professor of Chemical Engineering at the University of Wisconsin-Madison. He received his B.E. degree at Yale and Ph.D. at the University of California at Berkeley.

  • Andrew J. Baker

    1. Forest Products Laboratory, Madison, WI 53705
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    • Andrew J. Baker is currently a chemical engineer at the Forest Products Laboratory, Madison, Wisconsin. He received a B.S. in Chemical Engineering from the University of Wisconsin in 1956. His research interests include hydrolysis of wood, combustion of wood, charcoal production, corrosion of fasteners in wood, use of wood as a chemical resistant material of construction, effects of chemicals on the strength properties of wood, and wood as a source of cattle feed.


Numerical simulations of various reactors for the production of xylose from hardwood hemicellulose by dilute sulfuric acid hydrolysis have been developed to analyze the effects on reactor performance of heat and mass transfer as well as reaction kinetics. An economic objective function representing the incremental cost of producing a 10% xylose solution for fermentation to ethanol was calculated from the results of the reactor simulations to identify the operating conditions that minimize production costs for each reactor type. Lower production costs were estimated for percolation and continuous counter-current reactors; the cost for xylose production in a continuous co-current reactor is significantly higher. Production of ethanol from hardwood hemicellulose is not economical with any of the reactors considered, but the models developed here may be used to analyze other process alternatives for use of hemicellulose via production of xylose.