PR-343-14607-R01 Miniaturized Gas Chromatography and Gas Quality Sensor

In natural gas transmission and distribution, many metering stations utilize gas chromatography to ensure the gas complies with the pipeline’s gas quality tariff provisions and to determine the chemical energy content of the gas for billing purposes. It is also used as a check on the operation of gas ultrasonic flowmeters through a calculation of the speed of sound in the gas. Because of limitations on existing gas chromatographs (GC’s), including high installed cost, analysis time, carrier gas consumption and others, there is a desire to consider alternate technologies for natural gas analysis. PRCI has sponsored a study of technologies that utilize the variation in absorption/scattering of optical wavelengths by different molecules. The purpose of this study is to extend that study to the use of additional technologies, such as MEMS (Micro-Electro-Mechanical Systems). This is not a new approach, but recent advancements offer a greater possibility of achievement of the desired goals than in the past. This study reviewed and evaluated work in process with MEMS technology to provide a smaller, less ex-pensive, lower-power and faster GC that can be utilized in a Class 1 Division 2 area. Developments at both commercial firms and in university MEMS research programs have been included. Since there have been several programs to evaluate ‘energy meters’ that attempt to measure gas quality by calculating the BTU content of a gas sample, this study focused on micro-GC’s that can make a much more precise measurement of gas quality.