Due to limited supply of traditional fossil based fuels, and increased interest in air and
water quality along with other environmental concerns, there has been a rise in the utilization of
biomass based energy sources. Many agricultural materials can be used for the production of
biofuels, including materials that are typically underutilized such as sweet sorghum bagasse and
otherwise nuisance species such as Chinese tallow tree seeds. The goal of this project was to
examine the relationship between the dielectric properties of sweet sorghum bagasse and Chinese
tallow tree (CTT) seeds, respectively, and frequency and moisture content; to determine pertinent
thermal properties of these materials, and to optimize process parameters of a continuous belt
microwave drying system for improved biofuel production.
Prior to microwave drying, the elemental composition, fatty acid composition, oil
content, and various thermal properties for each of the component layers of CTT seeds were
investigated. These tests revealed dramatic differences between each of the component layers of
CTT seeds. For both sorghum bagasse and CTT, the dielectric properties across a range of
moisture contents and frequencies were measured. The values obtained here were applied to the
calculation of the penetration depth of microwaves through the materials in order to illustrate
how these materials would behave when exposed to microwave energy. The dielectric properties
for each material were found to be dependent on both frequency and moisture content.
For microwave drying tests, the parameters investigated include microwave power levels
(300W, 750W, and 1.2kW) and ambient air temperatures (room temperature and 55°C) with total
residence time of 5 minutes. Data collected included humidity, temperature, sample surface
temperature, moisture content, and absorbed microwave power. The moisture removed when
microwaves are used is greatly in excess of the internal air moisture holding capacity, due to
forced removal of water from the samples via pressure gradients generated by direct interaction
with the water molecules in the matrix. Results indicate that microwave drying achieves results
better than the control with respect to moisture removed per unit energy input.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04132012-174640 |
| Date | 17 April 2012 |
| Creators | Picou, Laura A. |
| Contributors | Lima, Marybeth, Aita, Giovanna, Boldor, Dorin |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04132012-174640/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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