Application of Nutech Canister Sampling and Air Preconcentration System in Monitoring ODS and HFCs at Fugitive Emission Control Points in Industrial Parks

Background Introduction

Ozone Depleting Substances (ODS) are a class of chemicals that have harmful effects on the atmospheric ozone layer. They are mainly used as refrigerants, cleaning agents, foam blowing agents, and fire extinguishing agents. This group includes nine major categories: chlorofluorocarbons (CFCs), halons, carbon tetrachloride (CTC), methyl chloroform (1,1,1-trichloroethane), hydrochlorofluorocarbons (HCFCs), hydrobromofluorocarbons (HBFCs), bromochloromethane (BCM), methyl bromide (bromomethane), and hydrofluorocarbons (HFCs). The first eight categories of halocarbons, once released into the atmosphere, ascend to the stratosphere, where they accumulate. Under ultraviolet radiation, they release Cl· or Br· free radicals, which catalyze the photodissociation of ozone. This leads to the depletion of the ozone layer, allowing excess ultraviolet radiation to reach the Earth’s surface, thereby endangering human health and the biosphere. HFCs, on the other hand, are substitutes for phased-out ozone-depleting substances. Although they do not deplete ozone, they are potent greenhouse gases with high global warming potential.

Nutech Solution

Based on a deep understanding of the challenges involved in ODS and HFC analysis and leveraging extensive experience in practical applications, Nutech pioneered the development of a water and CO2 removal module tailored to the characteristics of ODS and HFC pollution at unorganized emission monitoring points in industrial parks. By integrating canister sampling with a water and CO2 removal module and a three-stage cryogenic preconcentration system, Nutech provides an advanced solution for monitoring and analyzing ODS and HFCs in the air at these emission control points.

The analysis of ODS and HFCs in the air at fugitive emission monitoring points in industrial parks refers to the “Technical Specification for Manual Monitoring of Ozone-Depleting Substances and Fluorinated Greenhouse Gases in Ambient Air,” published by the Ministry of Ecology and Environment in 2022 (hereinafter referred to as the “Technical Specification”). This specification recommends the use of an external calibration method with a calibration curve for air measurement at fugitive emission control points, with a suggested six-point concentration curve ranging from 0.5 ppb to 20 ppb. The concentration range can be adjusted based on the actual sample concentrations to ensure that the target compounds fall within the calibration range.

Through testing air samples from multiple fugitive emission monitoring points in industrial parks, Nutech has determined that the concentration range of ODS and HFCs varies significantly, spanning from sub-pptv to several hundred ppbv. This variation is related to the differences in production activities within the industrial parks and the diverse raw materials and processes used by different enterprises. To accurately quantify each analyte, Nutech optimized the calibration curve based on the characteristics of the actual samples, establishing three sets of curves—low, medium, and high concentrations—ensuring precise quantification of each target compound.

Test Result

Actual Sample Chromatogram

Figure 3 shows the TIC (Total Ion Chromatogram) for air from an unorganized emission monitoring point in an industrial park. The concentration range of ODS (Ozone-Depleting Substances) and HFCs (Hydrofluorocarbons) in this air sample varies widely, from 0.2 pptv to 50 ppbv. Most components have concentration values within 10 times the atmospheric background concentration, with only a few components reaching ppbv levels.

Table 1: Information on the 44 Test Components

Conclusion

Nutech Canister Sampling – Water and CO2 Removal Module – 3-stage Cold Trap Pre-Concentration – GCMS System can monitor and analyze at least 44 ODS (Ozone-Depleting Substances) and HFCs (Hydrofluorocarbons) in the air from fugitive emission monitoring points in industrial parks. Method validation data meet the related testing requirements and the system has been practically applied to sample analysis in multiple industrial parks in pilot areas.

For ODS and HFCs analysis needs, Nutech Instrumnets has introduced an upgraded application solution for preconcentrator. This upgrade involves replacing the trap and adding a water and CO2 removal module on top of the standard preconcentrator. This setup enables the analysis of dozens of ODS and halogenated compounds, including CF4 and NF3, and allows switching back to the original standard preconcentrator, thereby significantly improving instrument utilization and reducing costs.