Citation:

Thoma, E., Alireza Gitipour, I. George, P. Kariher, M. MacDonald, W. Champion, A. Edwards, J. Childers, AND V. Schmid. Mobile and Multipoint Process Unit Monitoring of Ethylene Oxide Emissions at a Chemical Facility in EPA Region 7. Air & Waste Management Association¿s Air Quality Measurement Methods and Technology Conference, Durham, NC, November 14 - 16, 2023.

Impact/Purpose:

This is an abstract and associated presentation titled “Mobile and Multipoint Process Unit Monitoring of Ethylene Oxide Emissions at a Chemical Facility in EPA Region 7” submitted to the Air & Waste Management Association’s Air Quality Measurement Methods and Technology conference to be held November 14–16, 2023 on Research Triangle Park, North Carolina. Ethylene oxide (EtO) is a hazardous air pollutant that can be emitted from a variety of difficult to measure industrial sources. Emerging next generation emission measurement (NGEM) approaches capable of time-resolved, low parts per billion by volume (ppbv) method detection limits (MDLs) can help facilities understand and reduce EtO and other air pollutant emissions from these sources yielding a range of environmental and public health benefits. In October 2021, a collaborative field effort was conducted at an EtO chemical facility in EPA R7 that had dual study objectives to both improve understanding of EtO emission sources within the facility and advance NGEM methods. This presentation describes the EtO emissions observed in and near the four defined source areas within the facility and provides details of the NGEM method development advances accomplished as part of the study. 

Description:

Ethylene oxide (EtO) is an important chemical feedstock and a hazardous air pollutant. There is growing interest in understanding and controlling EtO emission sources within chemical facilities to enhance worker safety and limit near-facility exposure potential. In addition to controlled stack sources, EtO emissions can occur from fugitive equipment leaks, wastewater handling, episodic releases, and process malfunctions that are more difficult to detect and assess. Next Generation Emissions Measurement (NGEM) approaches based on rapid high-sensitivity optical spectroscopic techniques provide additional options to be better characterize and understand emissions from this source category. In October 2021, a 4-day NGEM demonstration study was conducted in cooperation with a chemical facility in EPA Region 7. The facility processes annually ~100 tank railcars containing a total of ~7,700,000 kg of pure EtO in the production of industrial surfactants, emulsifiers, defoamers, and specialty chemical products. The goals of the study were to both characterize source emissions within the facility and further the development of NGEM approaches in a real-world setting. Two primary NGEM techniques were utilized, which included a fixed multi-point sampling and analysis approach as well as mobile measurements. As part of the multi-point sampling and analysis approach, sequentially sampled measurements were conducted at seven locations in and outside the process area using a CleanAir MET-44 continuous monitoring system fitted with a Picarro G2910 Cavity Ring-Down Spectroscopy (CRDS) EtO analyzer. One of these locations was collocated with a seperate Picarro G2920 CRDS EtO analyzer for comparison purposes. The second NGEM approach involved partial day mobile measurements at high time resolution using a second Picarro G2920 system operating under U.S. EPA Other Test Method (OTM) 33 protocols with supporting fixed place wind data. The mobile measurements were conducted near the processing unit and just outside of the facility. In addition to the real-time measurements, collocated canister grab samples were acquired for comparison purposes and subsequently analyzed via U.S. EPA Compendium Method for Toxic Organic (TO) 15. The presentation will discuss EtO source emission observations along with NGEM method development advancements and comparative measurements from the study.

Record Details: