Hydrothermal flames for subaquatic, terrestrial and extraterrestrial applications

Sivamohan N Reddy; Sonil Nanda; Jude A Okolie; Ajay K Dalai; Michael C Hicks; Uday G Hegde; Janusz A Kozinski

doi:10.1016/j.jhazmat.2021.127520

Hydrothermal flames for subaquatic, terrestrial and extraterrestrial applications

J Hazard Mater. 2022 Feb 15;424(Pt C):127520. doi: 10.1016/j.jhazmat.2021.127520. Epub 2021 Oct 15.

Authors

Sivamohan N Reddy¹, Sonil Nanda², Jude A Okolie³, Ajay K Dalai⁴, Michael C Hicks⁵, Uday G Hegde⁶, Janusz A Kozinski⁷

Affiliations

¹ Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India.
² Titan Clean Energy Projects Corporation, Craik, Saskatchewan, Canada.
³ Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
⁴ Department of Chemical and Biological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. Electronic address: ajay.dalai@usask.ca.
⁵ Low-gravity Exploration Technology Branch, Glenn Research Center, National Aeronautics and Space Administration (NASA), Cleveland, Ohio, USA.
⁶ Low-gravity Exploration Technology Branch, Glenn Research Center, National Aeronautics and Space Administration (NASA), Cleveland, Ohio, USA; Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
⁷ Faculty of Engineering, Lakehead University, Thunder Bay, Ontario, Canada.

PMID: 34749231
DOI: 10.1016/j.jhazmat.2021.127520

Abstract

Hydrothermal flames are formed in supercritical water in the presence of a fuel and an oxidant (usually air or oxygen). Integrating hydrothermal flames as the heat source for supercritical water oxidation helps to minimize the reaction time (to milliseconds), improve the reaction kinetics and reduce the chances of corrosion and reactor plugging. This review outlines state-of-the-art research on hydrothermal flames including the impacts of process parameters on flame ignition. The ignition and sustainability of hydrothermal flames are dependent on several factors such as the type of fuel and its concentration, type of oxidant (air and oxygen) as well as the temperatures and flow rate of the feed and oxidant. The article describes some novel applications of hydrothermal flames for clean energy production, geothermal energy recovery, deep well spallation, wastewater treatment, degradation of recalcitrant nitrogen-containing compounds and heavy oil upgrading. Finally, the challenges and future perspectives of hydrothermal flame applications are discussed. This review also highlights some technical considerations relating to hydrothermal flames such as the choice of organic solvent and its characteristics, preheating, ignition mechanism, flame stability and propagation, advanced reactor configurations, mixing with subcritical and supercritical components, recirculation zones, cooling mechanisms, corrosion and salt precipitation.

Keywords: Geothermal heat recovery; Heavy oil upgrading; Spallation drilling; Supercritical water oxidation; Underwater welding.