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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #242157
Title: Application of thermogravimetric analysis for the proximate analysis of livestock wastes

Author
item Cantrell, Keri
item Martin, Jerry
item Ro, Kyoung

Submitted to: Journal of ASTM International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2010
Publication Date: 2/15/2010
Citation: Cantrell, K.B., Martin, J.H., Ro, K.S. 2010. Application of thermogravimetric analysis for the proximate analysis of livestock wastes. Journal of American Society for Testing and Materials International. 7(3):Paper ID JAI102583 (available online at www.astm.org).

Interpretive Summary: Livestock manure may be used as a feedstock for high temperature bioenergy production processes. In order to use these processes, the manure must be properly characterized for volatile matter and ash content. Determinations of these components in livestock manure are not specifically mentioned in current American Standard Testing and Materials methods. In this study, we determine the volatile matter and ash contents in manures using a rapid instrumental technique called thermogravimetric analysis. The volatile matter content as well as the ash content of swine, dairy, rabbit, and poultry manures were the same as those values found by non-automated means. The ash content of swine sludge was the one exception with the instrumental assessment predicting less ash. Modification of the instrumental ash method aimed at shortening the run time generated similar results. Thus, instrumental ash determination in manure should occur above 600 degrees Celsius with preferences for the following method: zero-grade air at two to four instrumental furnace volumes per minute; heating rate of 11 degrees Celsius per minute; temperature range of 110 to 950 degrees Celsius; isothermal hold at 950 degrees Celsius for 10 minutes. Volatile matter instrumental determination should follow coal American Standard Testing and Materials methods.

Technical Abstract: There is worldwide interest in deriving increasing amounts of energy from bio-based agricultural materials including not only lignocellulosic residues but also a significant quantity of available livestock manure. This manure can be used as a feedstock for various thermochemical conversion processes such as pyrolysis and gasification. In order to apply these processes, the manure must be properly characterized for volatile matter and ash contents. Determination of these components is not mentioned specifically in current American Standard Testing and Materials for livestock manure. In this study, we employed the use of thermogravimetric analysis for the rapid assessment of volatile matter and ash content in swine, dairy, rabbit, and poultry manures using references from the American Standard Testing and Materials coal and coke standards. The thermogravimetric analysis assessment of volatile matter in the manures was the same as those values found by non-automated means (American Standard Testing and Materials Directive 3175-07) ranging from 47 to 78 dry weight percent. The thermogravimetric analysis assessment of the ash was also the same when compared to ash results via conventional means following American Standard Testing and Materials Directive 3174-04. Ash values ranged from 4 to 47 dry weight percent. There was one exception when testing a high ash containing swine lagoon sludge. Under the thermogravimetric analysis method, this sludge underwent more complete devolatilization and oxidation. This was primarily attributed to the small sample size leading to uniform internal heating. Modification of the thermogravimetric analysis ash method aimed at shortening the run time generated similar results as both the original thermogravimetric analysis method and non-automated method. Thus, thermogravimetric analysis ash determination in manure should occur above 600 degrees Celsius with preferences for the following method: zero-grade air at two to four furnace volumes per minute; heating rate of 11 degrees Celsius per minute; temperature range of 110–950 degrees Celsius; isothermal hold at 950 degrees Celsius for 10 minutes. Volatile matter determination via thermogravimetric analysis should follow American Standard Testing and Materials Directive 3175-07.