PNNL-13501 - Pacific Northwest National Laboratory

Study Control Number: PN99070/1398
Fiber Hydrolysis Capability Development (a)
James A. Franz, Todd A. Werpy, Douglas C. Elliott
Vast U.S. resources of low-cost sugars from agricultural-derived products and byproducts are readily available for
conversion to chemicals, fuels, and neutraceuticals. In particlar, the fiber byproducts of corn processing that are currently
used as livestock feed are a major potential source of sugars, and the fiber-derived oils are also potential sources of
important nutraceutical substances, such as cholesterol-reducing sitosterols and tocopherols. Efficient extraction of
sugars and neutraceuticals from grain fiber will have significant economic impact to U.S. agriculture and will make
available substantial amounts of new feedstock for fuels and chemical production. Developing new approaches to
selective sugar and neutraceuticals extraction from fiber requires use of modern approaches in structural chemistry and
kinetics. This project applies modern kinetic and spectroscopic methods to develop new sugar and oil separation methods
that will enable use of a substantial fraction of corn fiber produced by U.S. agriculture and will result in improved
economics for biomass-derived chemicals and fuels.
Project Description
New processing capabilities will be supported by the
development of hydrolysis process information for use in
the production of value-added products from agriculturalderived
feedstocks. The processing capability will be
based upon laboratory testing, including chemical
mechanisms and chemical analytical procedure
development, that was conducted as part of this project.
The project used liquid and solid-state nuclear magnetic
resonance spectroscopy and chromatographic methods to
determine hydrolysis kinetics of cellulose, hemicellulose,
oligermic sugars, and starch with specific feedstock
targets of corn fiber and wheat shorts. Further, a method
was developed for detecting components in oil fractions
of grain fiber hydrolysate products. Procedures for the
measurement of tocopherols and related lipid-like
components were developed and applied to assess
conditions for separation of fiber components.
Introduction
This project examined kinetics of sugar production from
corn fiber and related materials. Potential economic
benefits to be derived from a detailed understanding of
fiber hydrolysis kinetics included
• reduced sugar cost (by as much as 75%) by enabling
use of abundant, low-cost biomass feedstocks
• tailored feedstock streams for each application based
on 5- and 6-carbon sugars
• reduced overall cost of fermentation and catalysis
products.
The identified benefits for DOE include a strong
understanding of hydrolysis and an expanded capability in
processing biomass-derived feedstocks.
Approach
We previously characterized oligomeric and
monosaccharide sugars derived from corn fiber. In that
project, sugar production from batch autoclave hydrolysis
experiments at a variety of temperatures and acidities was
examined. Because of limitations in heating rates and
contact times with the batch (as opposed to flow reactor)
equipment available, results were basically limited to long
exposure times that resulted in substantial conversion to
unwanted sugar dehydration products. Nevertheless, the
study identified major sugar decomposition products and
identified upper limits of conditions for fiber processing.
In order to provide realistic processing data, an improved
kinetic procedure was needed to develop accurate time
profiles for sugar production. Initial scouting studies
were carried out on model disaccharide compounds and
complete kinetic hydrolysis curves were derived for the
model compounds. Several different acids and conditions
were tested to evaluate the kinetics.
(a) Project started in FY 1999 as a task under the project entitled, “Sustainable Production of Value Added Chemicals and Products/Fiber
Hydrolysis.”
Separations and Conversions 421