GC Solution for the Automated Analysis of Benzene & Hydrocarbon Emission in Air

To comply with the strict emission requirements for Benzene and other volatile hydrocarbons at a refinery it is essential to determine the air quality and detect the emissions at ppm level. The Benzene in Air Analyser developed by Da Vinci Laboratory Solutions is an automated GC solution to determine the Benzene emissions and the C1-C6 hydrocarbons. The integrated sample preparation allows the sampling up to eight gaseous samples.

GC Configuration

The Benzene in Air application is based on an Agilent Technologies GC configured with a FID or TCD and a custom programmed temperature vaporisation (PTV) injector. The application is equipped with an analytical column and a pre-column to backflush the C1-C6 hydrocarbon matrix. The sampling unit uses a pump, a mass flow controller and a multi-positioning valve to collect samples from e.g. a Tedlar bag or to take a sample directly from the outside air. Based on this configuration the GC application determines the Benzene content and C1-C6 hydrocarbons in air samples in one consecutive run.

Automated Analysis & Sampling

Collect the samples in Tedlar bags and use the stream selection valve to select either standards, samples and/or multiple samples for an automated analysis. The PTV injection port is modified to contain a sorbent tube as an injection port liner to ensure a rapid absorption and desorption of Benzene.

Alternatively collect the sample on a sorbent trap using a programmable sampling pump. The sorbent trap is placed in the PTV inlet and automatically purged prior to thermal desorption and subsequent analysis. This proven sampling technique has already been used for the analysis of VOC in air.

Up to eight samples or standards can be automatically selected and sampled. The gas sampling unit automates the process of sampling, absorbing and desorbing. After benzene has eluted from the precolumn to the polar column, the remainder of the matrix is backflushed to vent. The Benzene in Air analysis requires 25 minutes. To extend the analysis to C6-C8 aromatic compounds (BTEX Analysis) just switch the backflush after elution of o-Xylene.

Excellent Repeatability

The Benzene in Air application shows an excellent performance using a custom calibration standard. The chromatogram displays the analysis of 1.117 mg/m3 Benzene in Air Standard containing 0.1% VOC’.s

Features of the Benzene in Air Analyser

• Automated analysis of Benzene & C1-C6 hydrocarbons in air in one run
• Analysis can be extended upto BTEX
• Integrated gas sampling, absorbing & desorbing
• Various options for sample collection
• Based on proven sampling technique for VOC in Air
• Up to 8 samples or standards can be selected and sampled
• Excellent performance specifications

For more information on the DVLS Benzene in Air analyser please contact Da Vinci Laboratory Solutions.