ODS5-Pro High-precision ODS and fluorinated gas monitoring system
[Backgroud]
Ozone-depleting substances (ODS), include six categories of halogenated hydrocarbons, such as CFCs, HCFCs, Halon, CCl4, ch3ccl3 and CH3Br. These compounds are mainly produced by industry and are used in refrigeration, cleaning and foaming. They can release halogen atoms in the stratosphere, which will catalyze the photolysis of ozone and reduce the amount of ozone in the stratosphere. As a result, ozone hole will form and lead to excessive ultraviolet radiation reaching the earth's surface, and endanger the safety of human beings and the earth's biosphere. In order to protect the human living environment, countries all over the world signed the Montreal Protocol in 1987 to limit the use and emission of ODS worldwide.
Fluorine containing greenhouse gases (F-gases), include four of the seven categories of greenhouse gases controlled in the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC), namely hydrofluorocarbons (HFCS), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3). Fluorinated greenhouse gases have extremely high global warming potential (GWP), such as GWP100 of NF3 is up to 15750, while GWP100 of SF6 is up to 23500. Although the concentration of these F-gases is extremely low, it plays an important role in global warming.
In order to prove the effectiveness of the implementation of international conventions such as the Montreal Protocol, it is necessary to conduct long-term monitoring of the concentration of ODS and fluorine-containing greenhouse gases in ambient air. The concentration of these species in the ambient air is at the ppt level, and the concentration of some species is even lower than 1 ppt. Due to the relatively small change of atmospheric concentration, the requirements for the detection limit and accuracy of the monitoring system are far beyond the level that conventional VOC monitoring methods can achieve. At present, ODS and F-gases are mainly monitored by two global networks: Advanced Global Atmospheric Gases Experiment (AGAGE) and National Oceanic and Atmospheric Administration (NOAA). The monitoring instruments used are developed and assembled by scientists, and there are no commercial products available until TIANJI ODS5-PRO project was lunched.
[Introduction]
Tianji ODS5-PRO is the first commercialized high-precision monitoring system for ODS and F-gases worldwide. It features an ultra-low temperature preconcentration sampling system with double traps, uses gas chromatography-mass spectrometry (GC-MS) as analytical instrument, and operated by fully automatic control system and software platform. ODS5-PRO can analyze about 50 diffierent ODS and fluorine-containing greenhouse gases in the atmosphere in high-precision automatically. The detection limit and accuracy of the system are comparable with the Medusa system of AGAGE.
[Features]
1. Large volume sampling
A high-precision mass flow controller is used to control the sampling volume (2L or even higher), which greatly improves the analysis accuracy.
2. Double cold trap system
Ultilizing a medusa-like double cold trap system with a wide temperature control range, the target compounds can be further separated and purified from the interfering components, so as to ensure the high sensitivity and reproducibility.
3. Ultra low cooling system
The system has a built-in cryocooler system, with a minimum temperature of - 200 ℃, which can condense most halogen-containing gas components with very low boiling point in the atmosphere.
4. Full automatic control
The process control software ODSControl can automatically control the valve position, trap temperature and other important parameters as well as the operation of gas chromatography and mass spectrometry through preset programs. It also features a built-in alarm system, which can notify the users in case of abnormal conditions, and take protective measures to ensure the safety of system.
5. Automatic data processing
The data processing software ODSDdata can automatically process analysis data and calculate concentration of each compounds in air. It also offers functions such as manual quality control and background value screening.
[Monitoring species and accuracy*]
Monitoring species
（1）ODS controlled by the Montreal Protocol
• CFCs: CFC-11, CFC-12, CFC-13, CFC-112, CFC-113, CFC-114, CFC-115
• HCFCs：HCFC-22, HCFC-141b, HCFC-142b, HCFC-124, HCFC-133a, HCFC-132b
• Halons: H-1301, H-1211, H-2402
• Carbon tetrachloride
• Trichloroethane
• CH3Br
（2）Fluorinated greenhouse gases controlled by the Kyoto Protocol
• HFCs：HFC-32, HFC-23, HFC-125, HFC-134a, HFC-152a, HFC-227ea, HFC-143a, HFC-236fa, HFC-365mfc, HFC-245fa
• PFCs: CF4, PFC-116, PFC-218, PFC-318, C6F14
• SF6
• NF3
（3）Other compounds
• CH3Cl, CH2Cl2, CHCl3
• CH2Br2, CHBr3
• TCE, PCE
• SO2F2, COS
Accuracy
• ≤1% for compounds concentration over 20 ppt
Detection Limit
• low to 0.1 ppt
Concentration Range
• 0.1 ppt - 10 ppb
*Species and values are subject to change.