Fecal Sludge as a Solid : Exploring Byproducts of the Sol-Char Sanitation System B. J. Ward, Lauren Hafford, Tesfayohanes Yacob, Wyatt Champion, Ryan Mahoney, Richard Fisher, Sandra Garcia-Fine, Leah Santiago, Lupita Montoya, R. Scott Summers, Alan Weimer, Karl Linden University of Colorado Boulder – Environmental Engineering and Chemical Engineering Departments

The Problems Commercial/Domestic Evaluation: Industrial Fuels Evaluation: • 2.5 billion people (40% of the global population) lack access to basic sanitation, and about 1.1 million still practice open Fecal Char Energy Content Dried Fecal Sludge vs. Fecal Char defecation1 • 1 Diarrhea kills more than 1.5 million people every year Higher Heating Values of Fecal Char Higher Heating Values of Fuels • 3 billion people, the great majority living in the least 30 • “Fresh” feces has a higher energy Char after a run developed countries, are living in energy poverty with no 25 content than pit latrine sludge Dried Feedstocks Charred Feedstocks Ash Content 2 Char made from access to affordable or healthy fuels 20 25 100 Rural women collecting firewood feces has an • Charring fresh feces improves 15 energy content energy content, but charring 20 80 Unimproved pit latrine

10 does not improve HHV of more 15 60 HHV (MJ/kg) HHV 5 ≤ 25.6 MJ/kg degraded sludge 10 40

0 (MJ/kg) HHV 5 20

0 200 400 600 800 • Large variability in fecal sludge Ash Content (% dry (% fuel) Content Ash Pyrolysis Temperature (°C) fuel characteristics 0 0 Fecal char produced at lowest pyrolysis temperature retains highest Fresh Feces Latrine FS 1 Latrine FS 2 The Sol-Char Sanitation Solution Fecal Char Briquettes The Ash Content Issue

1 Parabolic 1200 Higher Heating Values of Feces-Derived Fuels Ash Removal by Leaching 2 Starch 115°C 100 dishes Fiber optics AnthraciteAnthraciteCoalCoal Dried Feedstocks Charred Feedstocks concentrate Starch 350°C transmit energy to 1000 FecalFecal Char CharBriquettesBriquettes (10% (10 Starch)% Starch) sunlight a pyrolysis reactor Molasses + Lime (10% + 3.5%) 35 80 CommercialCommercialCharcoalCharcoal Briquettes Briquettes The Sol-Char 800 Molasses + Lime (20% + 7%) 30 Residual Ash FecalFecal Char CharBriquettesBriquettes (10% (10 Molasses)% Molasses) System creates Minimum acceptable IRI 25 60

600 FecalFecal Char CharBriquettesBriquettes (20% (20% Molasses) Molasses) Ash-free Acid Soluble Ash briquette briquette

usable products Bituminous briquette 20 40

without grid 400 SugarcaneSugarcane Bagasse Bagasse 15 Ion Exchangable Ash Percent of Ash (%) Ash of Percent energy, water, or (MJ/kg) HHV 10 WoodWood 20

sewage Index Resistance Impact 200 No ash removed Water Soluble Ash energy standard energy

LigniteLignite Coal Coal FAO Minimum 5

Minimum FAO Minimum standard energy infrastructure by 0 0 0 harnessing solar 0 5 10 15 20 25 30 35 Fresh Feces Latrine FS 1 Latrine FS 2 Fresh Pit 1 Pit 2 Impact Resistance Index (IRI) for 0 5 10 15 20 25 30 35 3 Reactor thermally Higher Heating Value (MJ/kg) Feces energy to power a human fecal char briquettes made Higher Heating Value (MJ/kg) 4 inactivates human Elemental Content of Ash high-temperature from different binder configurations. HHVs of common solid fuels and human fecal char Marketable end waste 60 reactor that briquettes manufactured in this study. Bars Feces Pit Latrines Sewage sludge (Zevenhoven 2012) products are indicate range of reported values from literature. 50 created converts human waste to char. 40 30 The strength and energy content 20

The Sol-Char Sanitation System was developed as a proof-of-concept prototype for the Bill & Melinda of fecal char briquettes are mass) (by Ash of % 10 Gates Foundation Reinvent the Toilet Challenge. This prototype can process 2 kg of feces and 4 kg of competitive with commercial 0 urine with 4 hours of sunshine. briquettes. SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K2O P2O5 SO3 Marketable Byproducts of Sol-Char Waste Treatment Fecal char briquette Next Steps: Kampala FS Study Soil Amendments Dried Fecal Sludge Biochar Next Steps: Briquette Cooking Emissions Study • Repeat fuel analysis and ash speciation on fecal sludge a soil amendment that increases a safe-to-handle (disinfected) samples collected from vacuum trucks in Kampala, Uganda compostable material yields in soils and improves poor, sandy, and acidic soils • Make recommendations for best pre-treatment methods Emissions testing facility at CU Water boil test stove to maximize fecal sludge fuel value Fertilizer Nutrient Enriched Biochar Disinfected Urine a fertilizer made by fortifying biochar a ready-to-use fertilizer produced by References with urine thermally treating and disinfecting urine 1. WHO/UNICEF. Progress on Sanitation and Drinking-Water 2014 Update, WHO: Geneva, Switzerland, 2014; p 22. 2. WHO UNDP. The Energy Access Situation in Developing Countries, WHO: Geneva, Switzerland, 2009. 3. Schlag N, Zuzarte. Market barriers to clean cooking fuels in Sub-Saharan Africa, Working Paper Stockholm Environment Solid Fuels Institute, 2008. Dried Fecal Sludge Charcoal Briquettes 4. Gold M, Murray A, Niwagaba Ch, Niang S, Strande L. Faecal Sludge – From Waste to Solid ?, Sandec News 14, 2013. an industrial fuel that requires less solar a cooking fuel with an energy content Char briquettes energy to produce and has a lower ash comparable to traditional Acknowledgements content currently on the market Finalizing updates to cookstoves emissions testing laboratory facility at CU Boulder

SOLID FUEL PRODUCTION is a lucrative way to offset the cost of sanitation systems • Emissions testing underway to compare air pollution from Briquettes on an in urban areas with an industry presence. burning fecal char briquettes to other solid fuels Indian cookstove - CO, CO2, PM (size distribution, heavy metals contents, ECOC) • Charcoal production for commercial and domestic cooking is a $10 billion industry in • Water boiling testing in charcoal cookstove underway to 3 Sub Saharan Africa. compare fuel efficiency performance to other solid fuels • 45% of industry representatives interviewed in Kamapala would immediately adopt • Next, engineer briquette recipe to optimize durable, energy- fecal sludge biomass providing it met their process requirements.4 dense, slow-burning fuel