Canadian Crude Quality Technical Association - Project - Vapour Pressure
| Vapour Pressure |
Start Date
June 2013
Background
A project proposal for improving crude vapor pressure measurement was initially presented by Trans Canada Pipelines (TCPL) in early 2012. During the remainder of the year both TCPL and Imperial Oil (IOL) presented additional data supporting the need for improved measurement methods. This was largely in part due to conflicts between measured vapor pressure data and the API nomograph conversions from RVP that were used for EPA tank emission calculations.
A workshop hosted by the Alberta Research Council (now InnoTech Alberta) in February of 2013 solidified the need for work in this area and the project was launched a few months later as a participant based project.
A significant volume of data was presented comparing ASTM D323 RVP data versus ASTM D6377 VPCR4(37.8°C) data as well as comparisons of vapor pressure variations due to sampling methods.
This project became a CCQTA sponsored project in 2016.
Milestones as of September 2024
The following publications/standards have been developed as part of project activities:
- ASTM D7975-14 — Crude Oil Vapor Pressure Field Tester (VPCR-F). 2014
- ASTM D8003-15a — Determination of Light Hydrocarbons and Cut Point Intervals in Live Crude Oils and Condensates by Gas Chromatography. 2015
- ASTM D8009-15 — Manual Piston Cylinder Sampling for Volatile Crude Oils, Condensates, and Liquid Petroleum Products. 2015
- CCQTA Letter to Industry Regarding Vapor Pressure and Light Ends Measurement. 2015
- CCQTA Temperature Correction of D7975 Field Vapor Pressure Measurement. 2016
- CCQTA Vapor Pressure Best Practice published. 2017
- ASTM D8236-18 — “Standard Practice for Preparing an Equilibrium Liquid/Vapor Sample of Live Crude Oil, Condensates and Liquid Petroleum Products using a Manual Piston Cylinder for subsequent liquid analysis or gas analysis by Refinery Gas Analyzer”. 2019
- Transport Canada (TC) is collaborating with the Canadian Crude Quality Technical Association on the Inter-laboratory Study for ASTM D7975 and D8003, by providing in-kind support (collection of crude oil samples during TC’s Task 4 sampling and analysis campaign), as well as financial support for the required subsampling and characterization of the crude oil samples.
- Sampling for the ILS is complete with 8 samples captured by single phase sampling method. Both D8003 and D6377 have been completed on each sample and results were sent to the ASTM statistician for evaluation for the ILS.
- An advisory was published in November 2021 regarding ASTM D6377 and the impact of agitation on vapour pressure measurement.
- A revised CCQTA advisory was published in April 2021 regarding ASTM D6377 and the impact of agitation on measurement. This revision followed significant discussion at both the December 2020 and March 2021 meetings regarding details of the initially published advisory. Feedback from members as well as vapour pressure instrument manufacturers was incorporated into the revised version. The outcome was that increased agitation is a short-term mitigation strategy however the test method equilibrium criteria is the root cause.
Recent Updates
- Vapor pressure has recently emerged as a hot topic again with the release of proposed crude tank VOC emission regulations by Environment and Climate Change Canada (ECCC).
- A CCQTA technical review of the regulation exposed several areas of concern related to the use of vapor pressure to estimate VOC emissions.
- On 2024-09-12 the CCQTA sent a letter to ECCC documenting the concerns and proposed several recommendations. CCQTA members are welcome to review the letter via the members area of the CCQTA website under [Projects][Active Projects][Vapor Pressure][CCQTA Letter to ECCC 2024-09-12].
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