Presentation Profile
Understanding the Relationship Between On-Line and Laboratory Gasoline Vapor Pressure Results for Tighter Process-Blending
Currently Scheduled: 10/16/2019 - 1:00 PM - 1:20 PM
Room: Iris Room
Main Author
Jason Nick - AMETEK Petrolab
- George Hadl - AMETEK Grabner Instruments
Abstract:
Gasoline vapor pressure mini-methods and their correlations to ASTM D323 and D4953 are often misunderstood. The regulatory method, ASTM D5191, requires sample preparation for correlation with the mentioned methods. Inclusion of air-saturation and process-sample conditioning for on-line vapor pressure measurement is difficult when considering the short measurement interval of premium, on-line vapor pressure analyzers. This paper identifies the challenges presented by current mini-method correlations to ASTM D4953 (slope). Through the employment of ASTM D6378, process and lab results can be directly compared with zero sample preparation, resulting in more accurate blending against the regulatory vapor-pressure specification. By identifying the pressure contribution of fixed and dissolved gases, the ‘absolute’ pressure of the parent sample can be calculated. Supporting data will be used to show that the absolute pressure of both lab and process results, assuming no decomposition from sampling, is the same. Although finished gasoline is certified through ASTM D5191, ASTM D6378 allows for a ‘behind the scenes’ comparison between lab and process VP results, that returns less giveaway and more profit.
