Details of SP-3420A Gas Chromatography Instrument for Natural Gas Analysis:
System Introduction:
Full component analysis applicable to natural gas and refinery gas
The instrument system is equipped with 4 valves and 5 columns, consisting of two sampling/blowback ten way valves, two bypass switching six way valves, five chromatographic columns, and two high-sensitivity TCD detectors. It can provide the content of saturated hydrocarbons C1~C50, H2, He in the full concentration range, as well as the content of CO2, H2S, N2, O2, and C6+boiling point above hexane (as a blowback peak) in natural gas.
The instrument process meets and exceeds the methods of ASTM1945 and GPA2261.

Natural gas (refinery gas) four valve five column analysis chromatogram
(omitted)


Process diagram of refinery gas four valve five column system:

working principle:
The measurement of this system is carried out on two channels, channel I is used to analyze H2 and He, and channel II is used to analyze N2, O2, CO2, H2S, and saturated hydrocarbons C1 to C5.
After the sample is injected through the valve, it is separated by chromatography column 5 on channel I. H2 and He are detected on TCD1, and the subsequent components are backflushed and vented. At the same time, the sample enters the separation system on channel II and is separated by pre column 1, changing the column flow direction to allow C6 and heavier fractions to flow out as a peak. Light hydrocarbons and permanent gases are sent to column 3 and isolated, allowing C30-C50 to flow out of column 2, C1, N2, and O2 to enter column 4 and be isolated, while C2 and CO2 are separated and detected from column 3. Finally, C10, N2, and O2 flow out of column 4 for detection.
The processing and quantification of data are completed by a dedicated natural gas workstation, and the calorific values of each component (molar calorific value, mass calorific value, volume calorific value, and Wopo index) and other parameters are obtained. The switching of valves is completed by a reverse control workstation.


characteristic:
1. The instrument system is a multidimensional chromatographic analysis method using a fully packed column and full TCD, with high column load and high degree of automation.
2. One injection can obtain the content of various components of natural gas.
3. Within the linear range, it is not affected by the injection volume and does not have strict requirements for injection.
4. The two channels are independent of each other. If there is no need to detect the content of H2 and He, only channel II can be used.
5. N2 and O2 are detected separately
6. This analysis system is for the full component analysis of natural gas, with simple quantification and convenient use of normalization method with correction factors or external standard method for quantification.
7. The system process is suitable for all applications that require the separation of N2, O2, CO, CO2, CH4, and C2 to C5 hydrocarbons.
8. After expansion, the system can analyze the monomer hydrocarbon content of C10-C140 and C14+in natural gas (FID detection).