Development of Steady State NO2:NOX Control via an Independent Nitric Decomposition System for the Exhaust Composition Transient Operation Laboratory
2022-01-0665
03/29/2022
- Content
- Southwest Research Institute (SwRI) utilizes the burner-based Exhaust Composition Transient Operation LaboratoryTM (ECTO-LabTM) to accurately simulate transient engines and replicate real exhaust that is produced by light and heavy-duty engines. This system can generate and dose NOx over transient cycles from a range of 20 ppm to 1200 ppm where the NOx is generated by the in-situ decomposition and combustion of nitromethane. In the combustion and decomposition of nitromethane over 95 % of the NOx generated is in the form of NO. To authentically simulate exhaust gases, it is necessary to account for the distribution of the NO to the NO2. Since previous work has established that the decomposition of nitric acid can be utilized as a method to generate NO2, the objective of this project was to develop control of NO and NO2 within SwRI’s ECTO-Lab through the decomposition of nitric acid. In addition to this, a system was built capable of generating NO2 and NO independently of the ECTO-Lab via nitric acid decomposition. It was determined that NO2:NOX control can be achieved by varying the nitromethane flow rate and nitric acid flow rate. Total NOX control was approximately ± 20 ppm of the target 1000 ppm, and the gas phase HNO3 concentration was maintained below 3 ppm for all operating points. The maximum NO2:NOX ratio achieved was 90%, and the minimum was 2%. This proves that when utilizing the HNO3 decomposition system, the ECTO-Lab has the capability of controlling the NO2:NOX distribution at steady-state.
- Citation
- Wheeler, S., "Development of Steady State NO2:NOX Control via an Independent Nitric Decomposition System for the Exhaust Composition Transient Operation Laboratory," SAE Technical Paper 2022-01-0665, 2022, .