TY - JOUR
T1 - Using hydrothermal carbonization for sustainable treatment and reuse of human excreta
AU - Yahav Spitzer, Reut
AU - Mau, Vivian
AU - Gross, Amit
N1 - Funding Information:
This study was funded by the Rosenzweig-Coopersmith Foundation (USA) and the Israeli Water Authority . The authors would like to thank, Drs. Frits Caspers, Beatrice Bressan and Sergio Bertolucci from the European Organization for Nuclear Research (CERN, Switzerland) and Dr. Yaakov Garb (Ben Gurion University) for assisting with the pilot scale reactor design and donation. From Ben Gurion University, we also thank Dr. Itamar Giladi for helping with the statistical analysis, Drs. Sofiya Kolusheva, Roni Kasher and Amos Russak for their assistance with the analytics. Lastly we thank Paratherm for donating the heat-transfer fluid used in this research.
Funding Information:
This study was funded by the Rosenzweig-Coopersmith Foundation (USA) and the Israeli Water Authority. The authors would like to thank, Drs. Frits Caspers, Beatrice Bressan and Sergio Bertolucci from the European Organization for Nuclear Research (CERN, Switzerland) and Dr. Yaakov Garb (Ben Gurion University) for assisting with the pilot scale reactor design and donation. From Ben Gurion University, we also thank Dr. Itamar Giladi for helping with the statistical analysis, Drs. Sofiya Kolusheva, Roni Kasher and Amos Russak for their assistance with the analytics. Lastly we thank Paratherm for donating the heat-transfer fluid used in this research.
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/12/20
Y1 - 2018/12/20
N2 - Poor sanitation due to improper treatment of human excreta, and energy scarcity are global problems with only partial solutions. Thus, feasible conversion of human excreta into safe, reusable “products” and renewable energy could be advantageous. The research objectives were to study the properties and major chemical processes occurring during hydrothermal carbonization of raw human excreta with typical solids content, as well as exploring potential use of the resulting hydrochar and aqueous phase. Human excreta (often considered as black water) were hydrothermally carbonized in a set of nine 50-mL laboratory batch reactors under a range of severities, a single parameter obtained from a coalification model that represents the combination of temperature and time. Three temperatures (180, 210 and 240 °C) and reaction times (30, 60 and 120 min) were used. The physicochemical characteristics such as yield, elemental composition, organic matter and calorific value of the hydrochar (solid phase) were studied. Aqueous phase was characterized for carbon, nitrogen, macro and micronutrients composition. In addition, the potential use of the hydrochar and aqueous phase were studied. There was high correlation between severity factor and carbon content (R2 = 0.95) and calorific value (R2 = 0.89). Hydrochar yield decreased with increasing severity from 69 to 56%. Calorific values increased from 24.7 to 27.6 MJ/kg, falling within the calorific range of sub-bituminous coal. The aqueous phase demonstrated high nitrogen concentration, reaching up to 8178 mg/L total nitrogen, while N:P:K ratios were similar to those of commercial fertilizers. Pilot scale experiments resembled the results found in laboratory scale experiments for both hydrochar and aqueous phase and fitted the regression curves obtained from the severity factor. It is postulated that hydrothermal carbonization of human excreta could potentially serve as a sustainable sanitation technology with a closed-loop cycle approach while recovering energy and nutrients.
AB - Poor sanitation due to improper treatment of human excreta, and energy scarcity are global problems with only partial solutions. Thus, feasible conversion of human excreta into safe, reusable “products” and renewable energy could be advantageous. The research objectives were to study the properties and major chemical processes occurring during hydrothermal carbonization of raw human excreta with typical solids content, as well as exploring potential use of the resulting hydrochar and aqueous phase. Human excreta (often considered as black water) were hydrothermally carbonized in a set of nine 50-mL laboratory batch reactors under a range of severities, a single parameter obtained from a coalification model that represents the combination of temperature and time. Three temperatures (180, 210 and 240 °C) and reaction times (30, 60 and 120 min) were used. The physicochemical characteristics such as yield, elemental composition, organic matter and calorific value of the hydrochar (solid phase) were studied. Aqueous phase was characterized for carbon, nitrogen, macro and micronutrients composition. In addition, the potential use of the hydrochar and aqueous phase were studied. There was high correlation between severity factor and carbon content (R2 = 0.95) and calorific value (R2 = 0.89). Hydrochar yield decreased with increasing severity from 69 to 56%. Calorific values increased from 24.7 to 27.6 MJ/kg, falling within the calorific range of sub-bituminous coal. The aqueous phase demonstrated high nitrogen concentration, reaching up to 8178 mg/L total nitrogen, while N:P:K ratios were similar to those of commercial fertilizers. Pilot scale experiments resembled the results found in laboratory scale experiments for both hydrochar and aqueous phase and fitted the regression curves obtained from the severity factor. It is postulated that hydrothermal carbonization of human excreta could potentially serve as a sustainable sanitation technology with a closed-loop cycle approach while recovering energy and nutrients.
KW - Black water
KW - Human excreta
KW - Hydrothermal carbonization
KW - Liquid fertilizer
KW - Sanitation technology
KW - Solid biofuel
UR - http://www.scopus.com/inward/record.url?scp=85054689728&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2018.09.126
DO - 10.1016/j.jclepro.2018.09.126
M3 - Article
AN - SCOPUS:85054689728
SN - 0959-6526
VL - 205
SP - 955
EP - 963
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
ER -
