Patent ID: 6165251
Filing Date: 2000-12-26
Classification: B01D,G01N

Abstract:
A process for analyzing a waste gas stream to determine concentrations of volatile organic compounds contained in the waste gas stream, said process comprising:sampling the waste gas stream to establish a continuous waste gas flow through, in sequence, a waste gas line, a switching valve and a first vent line;periodically diverting a portion of the waste gas flow at the switching valve;feeding the diverted portion of the waste gas flow in a first direction through a sorbent in an organics concentrator, preferentially sorbing the volatile organic compounds on said sorbent, and venting, through a second vent line, the remaining waste gas essentially free of the volatile organic compounds;periodically discontinuing the feed of the diverted waste gas flow through the sorbent and feeding a carrier gas through the sorbent in a second direction, opposite said first direction, for desorbing the volatile organic compounds from the sorbent thus forming a concentrated gas sample;periodically feeding the concentrated gas sample to a gas chromatograph for analysis of the concentrated gas sample to determine concentrations of the volatile organic compounds;blending various amounts of at least one of the volatile organic compounds with a gaseous carrier to form calibration samples containing known, different concentrations of the at least one volatile organic compound;feeding the calibration samples through the sorbent in the organics concentrator for sorbing and desorbing of the calibration samples;feeding the calibration samples desorbed from the sorbent to the gas chromatograph for analysis and calibration of the apparatus.