LNG custody transfer measurement: New functionalities AML
Hint’s AML Information Management is a toolbox for technicians, engineers, operators, and managers to automate and optimize the workflows, improve trust in devices and save maintenance costs through data-driven decision-making. Every client and project is different. Therefore, our goal is to meet all customer requirements. So we designed a ‘standard’ software tool with the possibility to expand as desired.
A great example is the AML application at Cameron LNG. The original scope of the project, delivered in 2019, was the AML implementation and installation for the Liquefaction trains 1, 2, and 3 GC’s analyzers.
To comply with Cameron LNG’s customer’s requirements regarding ship loading, new fiscal metering GCs were recently installed and added to the existing AML. After a brainstorming session between Hint and Cameron LNG, it was decided to build new functionalities in AML that would be used to monitor the performance of the new fiscal metering GCs.
The new functionalities, compliant with the international standard for the analysis of Natural Gas and Similar Gaseous Mixtures by Gas Chromatography, GPA 2261-13, were successfully implemented in AML. The new functionalities aim to achieve a more efficient process of visualizing, storing, and reporting within AML.
The beauty of our business model is that new AML functionalities developed for an X customer will be available for free for all AML customers after the next software update. In that way, everyone can benefit from this. Are you curious about the new functionalities for LNG custody transfer measurement? Please read further.
Fidelity plots
Introduction
This procedure is based on response factors calculated from a selected reference standard using peak area measurements. Fidelity plots should be made periodically on calibration run data. For a specific instrument, the plot slope should remain essentially constant. A change in the hill usually indicates a difference in the gas composition or gas chromatograph performance. Should a Fidelity Plot indicate a change in composition, the reference standard blend should be removed from service, or the gas chromatograph should be calibrated.
Needs of Cameron LNG
During the LNG ship loading process, the customer witnesses the loading process and checks the validation. When the analyzed components are correct, a report is signed.
The requirement is to see during the validation of the GC the relation between the molecular weight and the measured individual components according to the GPA 2261-13 standard in a fidelity plot.
Integration with AML
A Bernos Fidelity plot was implemented in AML. The Bernos plot allows more components in the standard to be measured and plotted compared to the traditional Fidelity plot.
Available Functionality:
- Configure the fidelity plot per tag number
- Store fidelity plot data
- Molecular weight per component type ( can be done independently of the equipment)
- Response time factor
- Select which components form a group within the plot
- Generate the fidelity plot per tag number
- Graphical display
- Tabular test display of fidelity plot data
- Report
- Option to view previous plots
Linearity plots
Introduction
The principal method for determining the linearity of a gas chromatograph is to inject gases with a range of concentrations of each component of interest and plot the resulting peak areas. The linearity of the plot will indicate the linearity of the instrument over the component range.
Needs of Cameron LNG
The requirement is to be able to judge the linearity of the component responses to 3 gas blends.
Integration with AML
The peak areas produced by each component concentration (or level) are normalized and plotted in AML versus the component level concentration.
Available Functionality:
- Configure the linearity plot per tag number
- Store linearity plot data
- Molecular percentage average
- Lean
- Cal
- Rich
- Peak area
- Lean
- Cal
- Rich
- Calculate GPA norm
- Generate the linearity plot per tag number
- Graphical display
- Tabular test display of linearity plot data
- Report
- Option to view previous plots
- Molecular percentage average
Repeatability & Reproducibility report
Introduction
Repeatability is the expected precision within a laboratory using the same equipment and same analyst. Repeatability is the difference in analyzed values between two sequential runs.
Reproducibility is the expected precision when the same method is used by different laboratories using different equipment and different analysts. Reproducibility is the difference between two analyzed values.
Needs of Cameron LNG
The requirement is to produce GC’s Repeatability and Reproducibility reports, real-time calculated, stored, displayed, and reported by the GPA 2261-13 standard.
Integration with AML
The reference values of the certified gas composition are entered in AML or retrieved from the gas chromatograph if possible. The reference values are compared with readings retrieved from the gas chromatograph. The gas chromatograph executes three tasks to reduce the chance of outliers. AML calculates the deviation between the reference and the gas chromatograph reading. After the calculation, AML checks if the readings exceeded any limits or failed statistical analyses like trending.
Available Functionality:
- Configure GPA limits per component
- Generate repeatability and reproducibility results per component
- Tabular display of validation results
- Report
- Options to support different blends
Outcomes & Benefits for Cameron
Implementing Fidelity and Linearity plots and Reproducibility and Repeatability reports in AML leads to a more efficient way of working. These plots and reports can be real-time and automatically generated and stored, reducing the use and management of spreadsheets.
Results & Benefits for other clients
Every new functionality we develop for our clients will be available in the next update for free. A win-win situation for everyone! In that way, we can build the industry standard together.
