Monitoring gas pipelines

A new cost-effective system developed under a program sponsored by the Gas Research Institute in Chicago combines the advantages of continuous emissions-monitoring systems (CEMS) and predictive emissions-monitoring systems (PEMS). The development of a true nitrogen oxide sensor enables the user to measure nitrogen oxide directly as the traditional instruments do, with the potentially lower installed cost coming from the sensor-based predictive monitoring approach. To achieve this lower cost, the array of sensors must be packaged in a system that does not require the air-conditioned shelter typically required for CEMS. Therefore, the system has been designed for direct exposure to the weather for most applications. The continuous emissions monitor, called the CEMcat analyzer, uses 2 catalytic sensors: one to measure nitrogen oxide and the other to measure carbon monoxide. Oxygen is monitored by a sensor that uses well-known electrocatalytic zirconium oxide sensor technology. All 3 sensors are placed within a single heated manifold that contains critical flow orifices to ensure constant flow across each sensor. The technology of the analyzer is examined in detail.