Master of Science in Biological and Agricultural Engineering (MSBAE)
Biological and Agricultural Engineering
The need to reduce the United States dependence on foreign oil has never been greater. In the past decade emphasis has been placed on developing new and/or improved means to procure clean renewable energy. Liquefaction, which was developed for coal conversion over a century ago is one of these areas. Liquefaction used for biomass conversions to bio-oils is grouped under the thermochemical conversion (TCC) area of energy conversion methods along with gasification and pyrolysis. This thesis discusses liquefaction experiments conducted using varieties of Louisiana biomass feedstocks. Dairy manure collected from the Louisiana State University Dairy Farm in Baton Rouge, was the main feedstock studied using various temperatures (250-350)°C and catalysts (Na2CO3, NaOH, and K2CO3) to determine optimum operating conditions for these two parameters. A bench scale 300 ml pressure vessel was used to conduct hydrothermal liquefaction (HTL) experiments. The HTL process yielded oil products (hydrocarbons) for all experiments. Temperature was found to have a significant influence (P <0.05) on bio-oil energy content. One gram of sodium carbonate coupled with a processing temperature of 350°C is recommended as the optimum processing conditions for dairy manure in this study. However, the catalyst amount and type had had no significant effect (P > 0.05) on bio-oil when compared to no catalyst. Minimal differences were found when statistically comparing the types and quantities of catalysts with one another. Temperatures of at least 350°C are recommended for conversion of dairy manure to oil; although higher temperature trials were not conducted due to pressure vessel limitations. All additional feedstocks tested (tallowseed, switchgrass, pine sawdust, and poultry litter) yielded heating values that were comparable or higher than the 34.7MJ kg-1 reported as the maximum heating value for dairy manure oils. Oil yields are reported in the range of 20-33% on an organic basis.
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Midgett, Jason S., "Assessing a hydrothermal liquefaction process using biomass feedstocks" (2008). LSU Master's Theses. 241.