The natural gas, used by consumers is the processed one which is free from any impurity and very different from the natural gas, brought from underground up to the wellhead. Though the processing of natural gas is less intricate than the refining and processing of crude oil, it is equally obligatory, before it reaches end users. The unrefined natural gas consists of impurities like ethane, propane, butane, pentane and some higher molecular weight hydrocarbons which are separated at refineries during the processing of natural gas to produce ‘pipeline quality’ of dry natural gas. But, before the processing procedure could be commenced, the detection of such impurities becomes integral.
EST Inc. has invented an advanced sensor technology to detect and quantify the unwanted components present in the raw natural gas within a minute, rendering help to the refineries by making the processing procedure easy. The zNose® can perform analytical measurements of volatile organic vapors and odors in near real time with part per-trillion-sensitivity, precision and accuracy.
In order to analyse the calibre of zNose®, a testing procedure was carried out. A sample of natural gas was collected from a local residence using a one liter Tedlar bag. Approximately 5 milliliters was extracted and analyzed by zNose® equipped with a one-meter db-624 column. After the 3 second interval, the sample was injected into the zNose®. A further interval of 10 seconds was maintained, before the column ramping which was done from 40° C to 160° C at 5° C per second.
zNose® also detects low molecular weight compounds. The detectability of low molecular weight compounds is dependent upon the temperature of the sensor crystal. During the testing procedure, the detector temperature of 20° C was used, which could also be as low as 0° C as the response for zNose® is limited to compounds with boiling points above 0° C. The lowest weight compound detected was 274 counts in the natural gas sample that had an index of 479 or slightly below C5 (pentane).
zNose® software allows the user to quickly calibrate the results and to easily create individual peak response factors and alarm levels. Once a peak file has been defined, and scale factors determined, the software automatically displays peak readings in the desired units e.g. ppm. Also, the referencing retention time to n-alkanes provides a convenient peak naming convention in cases where the actual compound is unknown.
Hence, EST Inc.’s advanced electronic sniffer, zNose® is capable of catering to all the requirements of detecting, quantifying and calibrating the unwanted components present in the raw natural gas. It proficiently performed five replicate measurements on the natural gas sample at 1-minute intervals that profoundly demonstrated the precision and retention time stability of the zNose®. Henceforth, zNose® answers the need for speed, precision, and accuracy in the chemical analysis of all sorts of odors, fragrances, and vapors. zNose®’s ability to create virtual chemical sensor arrays to monitor these compounds makes this electronic sniffer, a useful process monitoring tool. Also, its capability to perform hundreds of chromatographic analyses per day makes it a cost-effective solution to quantify the impurities of raw natural gas. Therefore, zNose®’s unique features make it a one-stop solution, worth investing for the natural gas quality check.