Biomass Feedstock Production and Provision: Overview, Current Status, and Challenges - Engineering and Science of Biomass Feedstock Production and Provision - page 10

fi nal yield through site-specifi c management. However, the establishment and
management of energy crops may require technologies and methods different
than traditional crops. The information specifi c to novel energy crops, such as
which biophysical property to study and which sensing method is most useful,
has been lacking. The functional relationships to correlate remote sensing data
with physical attributes of the crops are also not established.
• Harvesting: The dedicated energy crops can be different from most forage crops
and, therefore, may require new harvesting technologies to be developed.
Dedicated and crop-specifi c machinery, therefore, needs to be developed. The
design of new equipment requires fundamental understanding of the crop prop-
erties, including morphological properties such as the distribution of vascular
bundles in stems, degree of lignifi cation, and geometric size of the stem as well
as biomechanical properties such as elastic modulus, tensile stress, and shear
stress. The improved understanding of the engineering properties of the novel
energy crops is, therefore, very important. Different cutting mechanisms and
their impact on cutting speed, energy consumption, and quality of cut needs to be
quantifi ed. This information must be used to design new harvesting equipment if
necessary. The performance of existing and new equipment must be systemati-
cally quantifi ed. Different operational practices, such as one-pass and multiple-
pass, also need to be systematically compared. The impact of weather on
harvesting operations will also be critical.
• Transportation: The low bulk densities create enormous challenges in handling and
transportation of biomass feedstock. Size reduction and densifi cation look promis-
ing for improving the transportation effi ciency. However, they need to be systemati-
cally studied. In particular, the energy consumption associated with these operations
needs to be quantifi ed. New equipment based on fundamental understanding of the
cutting and compression mechanism needs to be developed. Different modes of
transport must be compared. For road and rail transportations, the standardization
of transportation equipment as well as policies and regulation is also needed.
Software tools for optimal management and operation of the fl eet are also needed.
• Storage: Maintaining the quality of biomass during storage is critical. This is
especially true if the biomass is to be used for biochemical processing, because
microbial degradation can lead to substantial loss of cellulose, which is critical
to biochemical conversion. A fundamental understanding of the factors impact-
ing dry matter and quality loss needs to be developed. This will help in designing
optimal storage methods. The options for preparing biomass for further process-
ing by breaking down the biomass recalcitrance during storage must also be
evaluated. Evaluation of different storage methods by performing fi eld tests
using real scale facilities is also required. For building storage facilities, there
exists a trade-off between costs and quality control. Accurate biomass degrada-
tion patterns as a function of regional weather and incoming biomass quality are
required. The low bulk and energy densities also increase the total storage area
requirement. Apart from being cost-intensive, this creates safety issues.