Project Description

SCFI AquaCritox Demonstrator Unit

The Challenge

The EU’s Eco-innovation initiative aims to bridge the gap between research and the market by funding the commercialisation of environmental products and services.

Supported by this initiative, SCFI built a demonstrator unit to exhibit its innovative AquaCritox® wet waste treatment technology worldwide and to develop commercial opportunities. All components were housed in three specially adapted shipping containers.

SCFI engaged NeoDyne to develop a modular, structured automation system to control plant start-up, waste processing and shutdown. As this was a mobile demonstration plant, the automation solution had to be robust, modular and user friendly for quick set up and operation by multiple plant operators.

Our Approach

AquaCritox® is a hydrothermal oxidation process that involves the use of pressure, temperature and oxygen to effect partial or complete oxidation of the oxidisable components present in a sludge or contaminated water-based waste stream.

Typically, the process operates at minimum pressures of 165 Bar and up to 240 Bar and approximately 300°C to maintain water at near-critical or supercritical phase for the oxidation reaction. This process is achieved through a combination of high-pressure feed pumps and a unique pressure let down system with flow maintained through a series of heat exchangers.

The automation system had to react in a safe way to any deviations from these setpoints, including changes in waste stream viscosity and density. The system also had to maintain temperature, pressure and flow to various setpoints during the injection of liquid oxygen to each reactor to ensure full oxidation.

We developed the system using Siemens GRAPH logic in TIA Portal for an S7 1500 CPU with ET200SP remote rack. To allow each system work alongside the main state controller, we developed novel solutions for pressure control, safety shutdown, pressure let down, PID control loops, interlocks and oxygen injection control.

We designed a SCADA system with WinCC Professional and showed a simplified mimic of the process and key variables and setpoints for the user. We also configured a remote connection to the plant using an eWon Cosey router and VPN to allow for monitoring and support.

About SCFI

SCFI is an Irish environmental company specialising in safe, sustainable and cost-effective wet waste processing solutions.

SCFI’s pioneering AquaCritox® technology mitigates the economic and environmental issues surrounding sludge handling and disposal, allowing for the recovery of valuable resources and the use of heat generated in the process.

NeoDyne worked with SCFI to build an automation system for its AquaCritox demonstrator unit, a portable unit developed under the EU’s Eco-innovation initiative.

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