oa Remote gas detection system for identifying fugitive emissions

Identifying fugitive emissions from large scale LNG and gas processing and handling facilities is a difficult time and resource intensive process. Because of the limitations of hand held gas detection devices, and the sheer size and complexity of these facilities, smaller leaks may go undetected for extended periods of time and unintended releases may occur when plant personnel are not present or the area monitored. While fugitive emissions are typically not of immediate safety and human health concern taken individually, reducing the total emissions from a large plant or a regional industry footprint could very well have an appreciable positive impact on the environment. ExxonMobil Research Qatar (EMRQ) has developed a Remote Gas Detection (RGD) system that integrates computer vision algorithms and infrared (IR) optical technology that can autonomously scan for and identify small leaks such as those associated with fugitive emissions. Efficient identification of these emission sources will lead to better control and maintenance activities. The RGD system utilizes a custom build component based IR camera and integrated cooler assembly, and a computer vision algorithm that analyses the video output from the IR imagers to determine the presence of hydrocarbon plumes. Most hydrocarbon plumes have strong absorption peaks in the narrow mid-wave IR region. The algorithm takes advantage of the difference in contrast between a hydrocarbon plume and the background in each pixel of an IR image and the temporal changes due to plume behavior for the analysis. The algorithm compares sequentially collected IR images and uses a multi-stage confirmation process to confirm the detection and has built-in multiple filters that mitigate interferences like steam, and other moving objects such as humans and trees. Early field tests indicate that a 4 lb/hr propane leak could be autonomously detected from a distance of up to 800 feet. Also, initial testing comparing the RGD system to point and path detectors showed that a 2 lb/hr propane leak was successfully detected from 60 feet using the RGD system but did not elicit any response from a point detector located downwind 18 feet away. Multiple deployment opportunities at process facilities are currently underway. Results from field testing at these process facilities will help researchers investigate the effect of temperate and harsh weather conditions, the effect of varying temperatures and gain a better understanding of equipment wear and tear, maintenance requirements and possible life expectancies. These data sets will produce an accurate assessment of the performance of the RGD system under actual working conditions and will be used to qualify the technology for widespread adoption within the industry.