title: Evaluation of solid fuel char briquettes from human waste.
abstract: The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment.
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309-0428, United States.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Ward
authors.forename: Tesfayohanes W
authors.initials: TW
authors.lastname: Yacob
authors.forename: Lupita D
authors.initials: LD
authors.lastname: Montoya
mesh_terms: D002606:Charcoal / Q000737:chemistry*; D004602:Elements; D005243:Feces / Q000737:chemistry*; D005742:Gasoline / Q000032:analysis; D006361:Heating; D006801:Humans; D008962:Models, Theoretical; D013816:Thermodynamics; D014866:Waste Products
chemical_list: D004602:Elements; D005742:Gasoline; D014866:Waste Products; D002606:Charcoal