Shell - Continuous Automated Portable GC and Air Sampling Systems (CAPGAS)
Shell’s new Continuous Automated Portable GC and Air Sampling (CAPGAS) ) offers to calibrate a portable GC system with more established methods, and if needed provide one of these monitoring/modelling systems to use as a calibration standard. Useful to add to existing GC data or known air quality emissions including odor, GHGs (green house gases), toxics (including benzene) and other pollutants that are regulated or of concern.
Increasing requirements for air monitoring have recently led to the advancement of numerous new technologies. For many facilities with such needs, the most reliable, robust system offering the greatest insight and lowest cost is the Continuous, Automated Portable GC and Air Sampling (CAPGAS) System, operating in situ, and now offered by Shell Engineering & Associates, Inc.
Applications | Regulatory, Community Concerns, Odors, GHGs, Toxics, and More
If needed, portable GCs are incorporated within your facility’s existing monitoring program. If you don’t have a current air monitoring program, Shell Engineering can offer one of our ambient air monitoring services long-used for regulatory permitting. Now, by adding a CAPGAS system, your facility can supplement its air monitoring data with real-time, continuously-monitored, portable sensors, including options for remote data viewing and alarms.
CAPGAS is especially powerful if you have an idea of your gases of concern, including toxics, benzene, GHGs (Green House Gases), odor, and proxies/surrogates thereof. For criteria pollutants regulated via ambient air monitoring permitting methods, Shell continues to offer our turn-key systems and support technicians/engineers. (Please see our other new service product, Calibrated Real-Time Economic Air Monitoring Systems for more details on correlating your low-cost air sensor data with ambient air monitoring and modelling.)
Established Technology | Robust “Gold-Standard” Systems for Initial Assessment
CAPGAS is robust because it can be correlated with what EPA called “Gold-Standard” methods. CAPGAS is reliable because it is based on traditional methods (manual TO-15 canister sampling with lab GC), long-used for regulatory purposes to analytically quantify ambient levels of VOCs, HAPs, and odorous compounds. The traditional GCs used are one of the most accurate ways to identify multiple unknown chemical compounds from one sample, which helps facilities pinpoint pollutant(s) of concern for subsequent control options.
Laboratory GC with TO-15 canister grab sampling is a choice tool when the operator is unsure of which chemicals are in the air – and thus which pollutants may need additional control.
Laboratory GC with TO-15 sampling falls short in other areas. The TO-15 canister collects air at one point for one specific time period. If the chemical is not present during this period, the canister will not collect it for subsequent analysis. Multiple canisters are required to collect samples from multiple locations and multiple time periods. After the samples are taken there will be a time delay to collect the canister, send it to the laboratory, and for analysis/reporting. Elevated readings often come too late to establish a Corrective Action Plan. Higher levels of pollution may continue to be a problem since any actionable control options will be delayed until the data are returned. The value of the GC diminishes as more samples are needed to gain any insight.
The CAPGAS-type system is one of the best options for the economic feasibility for EPA’s recent technology review. They exhaustively-studied new/next generation of monitoring regulations, due, in part, to adapting reliable sampling and analytical methods to the portable version of GC, combined with near-real-time data automation. This method has been chosen for technical and economic feasibility particularly for situations where the levels of identified pollutants vary over time and/or space such that the passive sample collection followed by lab GC doesn’t give quick enough feedback.
To help facilities use this new technology for increased insight and automated data, Shell now offers the complete system for Continuous Automated Portable GC and Air Sampling (CAPGAS).
Typical CAPGAS System
- The system is sited according to your concerns or per regulation.
- The GC readings are performed at the facility (not at the laboratory).
- The output from the Portable GC is typically one reading every 10 to 15 minutes.
- Pollutant concentrations are saved with a time-stamp using data-loggers which can be read remotely and alarm if pollutant levels are exceeded.
- The Portable GC can be moved around if readings at different locations are needed.
- Multiple GCs used at a facility can be used to triangulate emission sources to determine which piece of equipment may be malfunctioning.
- Shell can perform or guide with the accompanying modelling. It can range from simple guidance equations, such as those in the new fenceline regulations, to full ambient modelling.
- The facility can opt to co-site our meteorological stations or use existing weather data available online through the National Weather Service, per regulations as applicable.
- Solar-powered options are now possible in many locations.
- With manual TO-15 sampling and laboratory GC analysis, correlations are more difficult to establish and the higher levels of pollution may continue to be a problem since any control options will be delayed until the data are returned
Using CAPGAS provides a more robust sampling program and provides the facility with data in a more timely and usable manner.
Please contact Shell Engineering to explore this and other new sampling and analytical methods for your regulatory and troubleshooting needs.