Auto-calibrating, Air Quality Monitoring System

About This Grant

Project Summary: In 2021, chemical manufacturing industries accounted for roughly 529,000 workers, and “Extraction” accounted for 226,840 workers in the U.S. oil & gas industry. With projected growth rate of 3.8% annually in the U.S. oil and gas industries, worker exposures to harmful levels of petrochemicals are likely to increase. From 2003-2015, this industry reported 148 fatal injuries from exposures to “chemicals and chemical products.” Long-term worker exposures are not well tracked, and monitoring only occurs after a problem or illness is identified. To help address this deficiency, Seacoast proposes to develop a fully automated indoor air quality (IAQ) analyzer with speciation capability. Seacoast's analyzer, the SeaPort AQ, combines a low-cost detector, two trap-and-purge, thermal desorption collectors for signal amplification, and the separation and resolving power of gas chromatography to (1) collect and analyze air in its immediate environment, (2) provide wirelessly networked data to industrial hygienists to track workplace exposure, (3) reduce the per-sample analytical costs by automatically including calibrations without user intervention. Remote programmability will provide low per-sample costs and the ability to track chemicals around the clock. In Phase I, Seacoast assembled and demonstrated a low-cost, chromatographic analyzer to speciate benzene, toluene, ethylbenzene, and xylene (BTEX) at levels well below the OSHA 8-hr (TWA) action level (500ppb) for benzene. We demonstrated automated field-blanks, calibration, and ambient air sample collection. We integrated an oven-less gas chromatography (GC) column specifically tailored for high resolution separation of BTEX from interfering compounds common to petrochemical and related industries. The analyzer uses a high-sensitivity chemical detector for hydrocarbons, which is insensitive to humidity and CO2. Miniature valves on custom designed manifolds eliminated the need for a bulky, expensive rotary valve, allowing the analyzer to cycle through collection, purges, and re-calibrations autonomously to verify analyzer performance. The Phase I prototype exceeded our proposed goal to sample and detect benzene at 50 ppb in under 30 minutes, demonstrating collection and detection of ~5ppb of benzene in less than 30 minutes. Seacoast's air quality analyzer can finally provide hourly vapor concentration tracking data, a vast improvement over weekly or monthly data to improve exposure or pollution tracking models at a per-sample cost of ~$1. In Phase II Seacoast will complete materials and system optimization and construct robust prototypes for field testing by two experts in the two primary industries interested in air monitoring: industrial hygiene and environmental pollution mitigation. These experts will perform side-by-side comparisons of our prototype and conventional systems, and field tests at contaminated environmental sites where BTEX and other chemical pollution is known to be present at elevated concentrations in the air.