Dissertation
DENSIFICATION AND BLENDING OF MANURE NUTRIENTS VIA PELLETING TO ENHANCE TRANSPORTATION AND UTILIZATION
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005486
Handle:
https://hdl.handle.net/2376/119308
Abstract
The potential for adverse environmental impacts from excess manure generated in regions with large concentrations of animal production is enormous. This research aimed to investigate ways of alleviating such threats via pelleting and blending of excess dairy manure nutrients, with canola and fish meals, to enhance their value, utilization, transport, and storage. Optimum conditions for pelleting composted dairy manure were investigated at moisture contents (MC) in the range of 10 – 35% (wet basis). Model equations were developed and validated for relationships between the feedstock MC and the pellets' characteristics. To improve its agronomic value, dairy manure compost was blended with canola- and fish-meals in ratios from 0% to 40% canola meal, and 0% to 20% fishmeal, before pelleting. The pre-pelleting MC was set at 21% based on optimum conditions previously established in this study, and 6-mm, 8-mm, and 10-mm dies were used for pelleting. The effects of the feedstocks blending ratios were evaluated against MC, unit and bulk densities, recovery, durability, and nutrient concentrations (total-nitrogen and phosphate) of the resulting pellets. Techno-economic analysis (TEA) of the process was also conducted to investigate the feasibility of this approach.
Results showed that the optimum MC for pelleting dairy manure composts is between 20 and 30% for both the 6-mm die and the 8-mm die, with respect to pellet recovery and durability. Pellets recovery index was found to be a good predictor of pellets durability, at a given MC. Results also showed that blending 5% of canola meal and fishmeal increased nutrient (total-nitrogen) concentration by up to 68% and 132%, respectively. The TEA demonstrated that the pelleting process is viable if the variables are optimized.
Results further indicated that blending and pelleting dairy manure compost even with small proportions of canola meal and fishmeal significantly enhanced not only nutrients concentration but also the quality of pellets. Consequently, this would result in reduced cost of transportation and storage, and improved utilization of nutrients, which would, in turn, mitigate environmental issues associated with excess concentration of nutrients near production locations.
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Details
- Title
- DENSIFICATION AND BLENDING OF MANURE NUTRIENTS VIA PELLETING TO ENHANCE TRANSPORTATION AND UTILIZATION
- Creators
- Femi Peter Alege
- Contributors
- Pius M Ndegwa (Advisor)Claudio O Stockle (Committee Member)Haiying Tao (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Biological Systems Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 186
- Identifiers
- 99900592057801842
- Language
- English
- Resource Type
- Dissertation