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Evaluasi Gas Chromatograph
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THE EVALUATION OF NATURAL GAS COMPOSITION ANALYSIS
FROM GAS CHROMATOGRAPHin PT PGN SBU II East Java
Dea AmeliaTEG II
360902/B
How Does Danalyzer Operate?
Analysis Result from DanalyzerManual Calculation Refers to
Old GPA and Latest GPA Standard
Calculations Comparisons
Conclusion and Recommendation
Danalyzer’s Specification
CONTENT
DANALYZER’SSPECIFICATION
Danalyzer Gas Chromatograph System with Model 2350 Controller
• Sample requirements : fluid phase: vapor; pressure: 15 to 30 psig, regulated to ±10%; flow rate: 50 cc/min, typical
• Carrier Gas : Zero grade helium (99.995% pure, with less than 5ppm water, and less than 0.5 ppm hydrocarbons)
• Column : OD 1/16”, ID 0.005” ; temperature 78-830C
• Detector Thermal Conductivity Detector (TCD) operating temperature 73-780C
• Cycle time 240 seconds
HOW DOES DANALYZER OPERATE?
Daniel C6+.exe
ANALYSIS RESULT FROM DANALYZER
Chromatogram
C6+
C3
nC4
iC4
iC5 nC5
N2
C1
CO2 C2
No. Component NameMole
PercentGallons/1000 scf
BTU Gross(BTU/scf)
Relative Density
1 C6+ 0.0676 0.0301 3.5700 0.0022
2 Propane 0.4723 0.1302 11.9100 0.0072
3 i-Butane 0.0909 0.0297 2.9600 0.0018
4 n-Butane 0.1073 0.0338 3.5100 0.0022
5 NeoPentane 0.0000 0.0000 0.0000 0.0000
6 i-Pentane 0.0408 0.0149 1.6400 0.0010
7 n-Pentane 0.0284 0.0103 1.1400 0.0007
8 Nitrogen 0.5077 0.0556 0.0000 0.0049
9 Methane 96.8801 16.4212 980.7200 0.5366
10 Carbon Dioxide 0.6614 0.1127 0.0000 0.0101
11 Ethane 1.1437 0.3059 20.2800 0.0119
Total 100.0000 0.5550 1025.7300 0.5786
Analysis Result
MANUAL CALCULATION REFERS TO OLD GPA
STANDARD AS USED IN DANALYZER
• GPA Standard 2261-89 “Analysis for Natural Gas and Similar Gaseous by Gas Chromatography”
• GPA Standard 2172-86 “Calculation of Gross Heating Value, Relative Density, and Compressibility Factor for Natural Gas Mixtures from Compositional Analysis”
• GPA Standard 2145-89 “Table of Physical Properties for Hydrocarbons and Other Compounds of Interest to The Natural Gas Industry”
Standard GasNo. Component
Calibration Concentration (%)
Peak AreaResponse
Factor
1 C6+ 0.03 74174.10 2.47E+06
2 Propane 0.999 1509688.80 1.51E+06
3 i-Butane 0.3 522534.00 1.74E+06
4 n-Butane 0.3 531852.00 1.77E+06
5 NeoPentane 0.0999 200255.54 2.00E+06
6 i-Pentane 0.0999 194827.98 1.95E+06
7 n-Pentane 0.0999 200231.57 2.00E+06
8 Nitrogen 2.496 2449150.08 9.81E+05
9 Methane 89.576 66309977.64 7.40E+05
10 Carbon Dioxide 1 1084720.00 1.08E+06
11 Ethane 4.999 4556838.45 9.12E+05Total 100
Composition CalculationNo.
Component Name
Peak AreaResponse
Factor%Mol
Unnormalized%Mol
Normalized
1 C6+ 174040.00 2.47E+06 0.070391147 0.070611
2 Propane 712900.00 1.51E+06 0.471744309 0.473215
3 i-Butane 157208.00 1.74E+06 0.090257093 0.090539
4 n-Butane 188848.00 1.77E+06 0.106522867 0.106855
5 NeoPentane 0,00 2.00E+06 0 0
6 i-Pentane 77928.00 1.95E+06 0.039958364 0.040083
7 n-Pentane 55296.00 2.00E+06 0.027588409 0.027674
8 Nitrogen 473277.00 9.81E+05 0.48233034 0.483834
9 Methane 71603800.00 7.40E+05 96.72725308 97.02886
10 Carbon Dioxide 720112.00 1.08E+06 0.663869017 0.665939
11 Ethane 919976.00 9.12E+05 1.009243596 1.012391
Total 99.68915822 100
Relative Density and Heating Value Calculation
No. Component Name Xi Gi Xi.Gi Hvi Xi.Hvi
1 C6+ 0.000706 3.2544 0.002298 5281.065 3.728994
2 Propane 0.004732 1.5226 0.007205 2521.921 11.93412
3 i-Butane 0.000905 2.0068 0.001817 3259.423 2.951034
4 n-Butane 0.001069 2.0068 0.002144 3269.848 3.493996
5 NeoPentane 0 2.4912 0 3994.22 0
6 i-Pentane 0.000401 2.4912 0.000999 4010.156 1.607389
7 n-Pentane 0.000277 2.4912 0.000689 4018.175 1.112007
8 Nitrogen 0.004838 0.96723 0.00468 0 0
9 Methane 0.970289 0.55392 0.537462 1012.337 982.2587
10 Carbon Dioxide 0.006659 1.5196 0.01012 0 0
11 Ethane 0.010124 1.0382 0.010511 1773.794 17.95773
Total 1 0.577925 1025.044
MANUAL CALCULATION REFERS TO LATEST GPA STANDARD
• GPA Standard 2261-00 “Analysis for Natural Gas and Similar Gaseous by Gas Chromatography”
• GPA Standard 2172-96 “Calculation of Gross Heating Value, Relative Density, and Compressibility Factor for Natural Gas Mixtures from Compositional Analysis”
• GPA Standard 2145-09 “Table of Physical Properties for Hydrocarbons and Other Compounds of Interest to The Natural Gas Industry”
Standard GasNo. Componen
Calibration Concentration
Peak Area Response Factor
1 C6+ 0.03 74174.10 4.04E-07
2 Propane 0.999 1509688.80 6.62E-07
3 i-Butane 0.3 522534.00 5.74E-07
4 n-Butane 0.3 531852.00 5.64E-07
5 NeoPentane 0.0999 200255.54 0.00E+00
6 i-Pentane 0.0999 194827.98 5.13E-07
7 n-Pentane 0.0999 200231.57 4.99E-07
8 Nitrogen 2.496 2449150.08 1.02E-06
9 Methane 89.576 66309977.64 1.35E-06
10 Carbon Dioxide 1 1084720.00 9.22E-07
11 Ethane 4.999 4556838.45 1.10E-06
Total 100
Composition CalculationNo.
Component Name
Peak AreaResponse
Factor% Mol
Unnormalized% Mol
Normalized
1 C6+ 174040.00 4.04E-07 0.070391147 0.070611
2 Propane 712900.00 6.62E-07 0.471744309 0.473215
3 i-Butane 157208.00 5.74E-07 0.090257093 0.090539
4 n-Butane 188848.00 5.64E-07 0.106522867 0.106855
5 NeoPentane 0.00 0.00E+00 0 0
6 i-Pentane 77928.00 5.13E-07 0.039958364 0.040083
7 n-Pentane 55296.00 4.99E-07 0.027588409 0.027674
8 Nitrogen 473277.00 1.02E-06 0.48233034 0.483834
9 Methane 71603800.00 1.35E-06 96.72725308 97.02886
10 Carbon Dioxide 720112.00 9.22E-07 0.663869017 0.665939
11 Ethane 919976.00 1.10E-06 1.009243596 1.012391
Total 99.68915822 100
Relative Density and Heating Value Calculation
No. Component Name Xi Gi Xi.Gi Hvi Xi.Hvi
1 C6+ 0.000706 3.2544 0.002298 5281.065 3.728994
2 Propane 0.004732 1.5225 0.007205 2521.921 11.93412
3 i-Butane 0.000905 2.0068 0.001817 3259.423 2.951034
4 n-Butane 0.001069 2.0068 0.002144 3269.848 3.493996
5 NeoPentane 0 2.4911 0 3993.718 0
6 i-Pentane 0.000401 2.4911 0.000999 4010.156 1.607389
7 n-Pentane 0.000277 2.4911 0.000689 4017.974 1.111952
8 Nitrogen 0.004838 0.9672 0.00468 0 0
9 Methane 0.970289 0.5539 0.537443 1012.337 982.2587
10 Carbon Dioxide 0.006659 1.5195 0.010119 0 0
11 Ethane 0.010124 1.0382 0.010511 1773.794 17.95773
Total 1 0.577904 1025.044
CALCULATIONS COMPARISONS
ParameterAnalysis by Danalyzer
Manual Analysis Refers to Old Standard
Deviation
%Mol Unnormalized 99.705 99.68915822 -0,01588865 %
Relative Density 0.5786 0.577924717 -0,116709899 %
Heating Value 1025.73 1025.044004 -0,066878805 %
The Comparison between Analysis of Danalyzer and
Manual Analysis Refers to Old Standard
ParameterAnalysis by Danalyzer
Manual Analysis Refers to Latest
StandardDeviation
%Mol Unnormalized 99.705 99.68915822 -0.01588865 %
Relative Density 0.5786 0.577903959 -0.120297495 %
Heating Value 1025.73 1025.043949 -0.066884214 %
The Comparison between Analysis of Danalyzer and
Manual Analysis Refers to Latest Standard
The Comparison between Manual Analysis Refers to Old Standard and Manual Analysis Refers to Latest Standard
ParameterManual Analysis
Refers to Old Standard
Manual Analysis Refers to Latest
StandardDeviation
%Mol Unnormalized 99.68915822 99.68915822 0 %
Relative Density 0.577924717 0.577903959 -0.003591789 %
Heating Value 1025.044004 1025.043949 -0.00000541215 %
CONCLUSION AND
RECOMMENDATION
Conclusion
• Analysis of the composition and physical properties of natural gas in PT PGN (Persero) Tbk. using Danalyzer Gas Chromatograph Model 2350 System Controller with the reference calculations are still using GPA Standard 2261-89, GPA 2172-86, and GPA 2145-89 or standards that have not been revised.
• Based on Danalyzer’s analysis on Thursday, February 11, 2010 at 11:01 o'clock at the offtake stations Gresik, the natural gas flow has methane content of 96.88%, with relative density of 0.5786 and GHV amounted to 1025.73 BTU / scf.
• There are small deviations between the results of natural gas composition analysis by Danalyzer and manual calculations.
• There are only small deviations between calculated composition of natural gas by GPA Standard 2261-89, 2172-86 GPA, and GPA 2145-89 with the calculation by GPA Standard 2172-96, 2145-09 GPA, and GPA 2261-00, so the results of Danalyzer calculation are still acceptable.
Recommendation
• The routine maintenance of Danalyzer Gas Chromatograph with Model 2350 Controller System in off-take station in accordance with the Standard Operation Procedure should be further enhanced.
• Although there are only small deviations between the calculation by old references and new references, but PGN should be able to respond this differences because the results of this analysis affects the custody transfer between PGN and suppliers, and distributed gas quality assurance.
• Revisions or updates should be performed against the reference standard used by Danalyzer.
THE END
THE FORMULAS
Calculate Response Factor
WhereK = Response factorAs = Peak area of standard
componentCs = Mol Percent of standard
component
s
s
C
A K
Calculate Mol Percent
Where :Cx = Mol Percent of component X
Ax = Peak area of component X
K = Response factor
K
A C x
x
Normalized Mol Percent
The unnormalized total should not vary more than ±1% from 100%. If so, sheck for possible errors or change in operating conditions of instrument between sample and reference standard run.
edunnormaliz
edunnormaliznormalized
%mol
Xcomponent %mol %mol
Calculate Relative Density
Where :G = Relative densityXi = Mol fraction of sample component
Gi = Relative density of sample component
n
1iiiGX G
Calculate Heating Value
Where :Hv = Heating valueXi = Mol fraction of sample
componentHvi = Heating value of sample
component
n
1iiiHvX Hv