(635c) Distributed Activation Energy Model for Solar-Driven Pyrolysis Kinetics of Untreated Human Feces

Authors: 
Fisher, R., University of Colorado at Boulder
Yacob, T., University of Colorado at Boulder
Mahoney, R. B., University of Colorado at Boulder
Linden, K. G., University of Colorado at Boulder
Weimer, A. W., University of Colorado at Boulder

Currently, 2.6 billion people on the planet do not have access to adequate sanitation and many communities in the developing world have neither the facilities nor the resources to properly treat human waste, leading to open defecation posing enormous public health risks as well as issues related to individual dignity and safety. Sanitation is not a problem unique to developing countries – modern sanitation processes are also unsustainable due to their often massive requirements for energy and water. Alternative waste treatment and conversion methods are likely to be incorporated as the demand for space and fresh water increases throughout the world. The Sol-Char Toilet, a solar-powered waste treatment technology developed at the University of Colorado Boulder, takes advantage of our most abundant renewable resource: the sun. In the Sol-Char Toilet, concentrated solar power (CSP) is transmitted through fiber optic cables to drive pyrolysis of human waste, converting a hazardous and unusable material to biochar. Pyrolysis, and biomass pyrolysis in particular, is a complex and non-homogenous set of reactions that take place at varied temperatures in the absence of oxygen. The kinetics of biomass pyrolysis can be adequately approximated by distributed activation energy models (DAEM) and many such models can be found in the literature for common biomass sources such as wood, grasses, and wastewater sludge. However, no model has been proposed for the pyrolysis of raw, untreated human feces – i.e. feces that has not entered the sewers or typical wastewater treatment process.  In this presentation, a distributed activation energy model for kinetics of raw, untreated human feces pyrolysis will be asserted.