Browsing by Subject "Supercritical water oxidation"

Due to the complexity of the reaction, waste sanitation using supercritical water oxidation controls requires a high level of strategy and design. A programmable logic controller was constructed using an Allen-Bradley 1756 ControlLogix controller and other industrial control components. This controller was chosen for its robustness and ease of integration with a multifaceted process. The supercritical water oxidation reaction has nearly fifty inputs and multiple outputs that are used to monitor and control the entire process. The responsibility of the control system ranges from process security and safety to adjusting mass flows of critical reaction components in order to reach a stoichiometric reaction balance. The controls system uses a sophisticated series of proportional integral derivative (PID) controllers to adjust the various control parameters such as reactor temperatures and reactant mass flows. Using a PID tuning method known as the Ziegler-Nichols method, the supercritical water oxidation reaction can be tuned and controlled to run as a self-sustaining waste sanitation unit.

Supercritical water oxidation (SCWO) had been investigated as an advanced technology for the removal of inert and stable organics found in wide range of wastes. Ammonia and nitrous oxide are confirmed in outlet of SCWO system treating municipal sludge. In this study, a mathematical model was established to simulate nitrogen reaction, in order to explore the kinetics of ammonia reaction and reduce the nitrous oxide generation. This developed mathematical model was trained by data from Duke Sanitation Solution group where a pilot-scale supercritical water oxidation facility is invested to treat municipal sludge. The final model was validated by practical data obtained from this facility, and give instruction on SCWO operation.