Introduction to Gas Chromatography System for Comprehensive Analysis of Natural Gas:

The natural gas comprehensive analysis dedicated gas chromatograph system consists 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.

Process diagram of refinery gas four valve five column system:

Working principle of natural gas comprehensive analysis dedicated gas chromatograph:

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 the chromatograph host.

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).

It can achieve full analysis of hydrocarbon components such as oxygen, nitrogen, methane, ethane, carbon dioxide, propane, isobutane, n-butane, n-pentane, isopentane, and C6+in natural gas with a single injection. For hydrogen sulfide analysis, only one manual injection of natural gas sample is required to obtain the hydrogen sulfide content. 1. The dedicated gas chromatograph for comprehensive analysis of natural gas complies with GB/T13610-2003 "Gas Chromatography for Composition Analysis of Natural Gas". 2 The instrument complies with SH/T0230-92 "Determination of Composition of Liquefied Petroleum Gas (Chromatography)" 3 The instrument can be used for component analysis of liquefied gas, liquefied gas mixed with air, as well as for component analysis of various gases prepared with hydrogen, nitrogen, methane (or propane; liquefied gas) as raw materials. 4. After completing a sample analysis, the instrument can report characteristic indices such as the content of the tested gas components, high calorific value, and low calorific value through a unique custom report. The natural gas analyzer is mainly used in liquefied gas plants, liquefied gas stations, natural gas companies, etc.

1. The dedicated gas chromatograph for comprehensive analysis of natural gas complies with GB/T13610-2003 "Gas Chromatography Method for Composition Analysis of Natural Gas"

2. The instrument complies with SH/T0230-92 "Determination of Composition of Liquefied Petroleum Gas (Chromatography Method)"

3. The instrument can be used for component analysis of liquefied gas, liquefied gas mixed with air, as well as for component analysis of various gases prepared with hydrogen, nitrogen, methane (or propane; liquefied gas) as raw materials.

4. After completing a sample analysis, the instrument can report characteristic indices such as the content of the tested gas components, high calorific value, and low calorific value through a unique custom report.

The natural gas analyzer is mainly used in liquefied gas plants, liquefied gas stations, natural gas companies, etc

Technical indicators of gas chromatograph for comprehensive analysis of natural gas

Technical parameters of gas chromatograph for comprehensive analysis of natural gas

Temperature control indicators
Column box: 5 ℃ to 400 ℃ at room temperature with an accuracy of ± 0.1 ℃
Injector and detector: above room temperature 6 ℃~399 ℃ accuracy ± 0.1 ℃ Program heating stage: fifth order
Program heating rate: 0.1 ℃~40 ℃/min at room temperature of 6 ℃~200 ℃
0.1 ℃ to 20 ℃/min when the temperature exceeds 200 ℃

Detector indicators
Hydrogen Flame Detector (FID):
Sensitivity Mt ≤ 1 × 10-11g/s (n-hexadecane)
Noise ≤ 5 × 10-14A
Linear range ≥ 106
Thermal conductivity detector (TCD):
Sensitivity S ≥ 4000mv. ml/mg (n-hexadecane)
Noise ≤ 20UV
Linear range ≥ 104
Nitrogen phosphorus detector (NPD):
Sensitivity: Nitrogen Mt ≤ 5 × 10-11g/s (azobenzene)
Phosphorus Mt ≤ 2 × 10-12g/s (malathion)
Noise N ≤ 2 × 10-13A
Electron Capture Detector (ECD):
Sensitivity Mt ≤ 1 × 10-13g/ml (r-666)
Noise ≤ 15UV
Linear range ≥ 5 × 103
Radiation source Ni63
Maximum operating temperature 350 ℃
Flame photometric detector (FPD):
Method: S or P filter
Sensitivity: 5 × 10-11g (s)/s (S in thiophene)
1.4 × 10-12g (p)/s (P in methyl parathion)

Main characteristics of natural gas comprehensive analysis dedicated gas chromatograph
The dedicated gas chromatograph for natural gas analysis adopts a large screen LCD display, advanced integrated control technology, high temperature control accuracy, automatic baseline zero adjustment, and easy operation;
☆ It has self diagnosis, over temperature power-off protection, file storage, calling, five step program heating function, and single column automatic compensation function;
The instrument is equipped with three injection devices: dual packed column and capillary column, and has an independent temperature control three gas path process. The chromatographic column box has a large capacity and can be installed with both capillary and packed columns simultaneously;
Equipped with six independent temperature control zones and an intelligent rear door opening system, the cooling speed is very fast; Each gasification chamber, detector, and amplifier adopts modular design, making installation and replacement very convenient;
Equipped with a separate and complete capillary analysis system, an independent capillary splitter injector (including diaphragm cleaning, splitting, and tail blowing adjustment). Optional capillary splitter/non splitter injector, cold column inlet injector, 0.53mm large-diameter capillary direct injector.
The dedicated gas chromatograph for natural gas analysis is equipped with five types of detectors: hydrogen flame detector, thermal conductivity detector, flame photometric detector, electron capture detector, and nitrogen phosphorus detector. Three detectors can be installed simultaneously, and users can choose according to their own analysis requirements. They can also add six way valve injection, conversion furnace device, etc; And it can achieve the series and parallel operation of detectors.
Note: This instrument can be converted into a chromatograph for other purposes