Exploring the unique attributes of hydrothermal oxidation as a compelling bioresource processing technology: PAPER & PRESENTATION
Gapes, D.1, Jefferson, B.2, Lei, R.1 and Stuthridge, T.1, 1Cetogenix Ltd, New Zealand, 2Cranfield University, UK
(free)
Hydrothermal oxidation (HTO), one of the Advanced Thermal Conversion (ATC) processes, has significant differentiating characteristics. Utilising a combination of temperature, pressure and oxidant (oxygen or air) to process complex organic materials within an aqueous environment, HTO breaks down the organic solids into simple soluble components and ash, suitable for recovery and integration within existing wastewater treatment infrastructure. Critical performance benefits include:
Operating at moderate temperature (180-300oC) and pressure (50-100bar), the process can be optimised for a wide range of applications and product yields.
The oxidation reactions generate sufficient heat to sustain the process without additional energy input.
Challenging chemical and biological contaminants, such as micro-plastics and pathogens, are destroyed.
The benefits to the water sector include eliminating the need for mass land application, reducing GHG emissions, and maximising resource recovery through enhanced biogas and nutrient recovery.
Important HTO processing and performance features are described, reinforcing its potential for biosolids conversion. Laboratory- and pilot-scale trials demonstrate 90+% solids destruction without the need for drying, the potential for eliminating external heat demand, and options for generating and separating organic carbon, nitrogen and phosphorus products.
We also outline the implications of alternative process integration flowsheets when using HTO within domestic wastewater treatment systems.
