How PRDewPointV1 can help you solve problems

• Calculate HCDP for Detailed Gas Analysis --- Input composition and pressure, output HCDP (Hydrocarbon Dew Point)
• Calculate HCDP for Gas Analysis with Lumped Hexanes Plus --- Input composition, Hexanes Plus molecular weight and pressure, output HCDP (Hydrocarbon Dew Point) and Hexanes Plus estimated composition
• Match Measured HCDP --- Input Measured HCDP, composition (including Hexanes Plus mole percent) and pressure, output Hexanes Plus estimated composition which matches Measured HCDP (Hydrocarbon Dew Point)
• Calculate HCDP using Hexanes Plus estimated composition at any pressure --- Input estimated composition and pressure, output HCDP (Hydrocarbon Dew Point)

PRDewPointV1 Key Features

Why PRDewPointV1 was developed

In 2000, prior to initiation of the API 14.1 program of experimental measurements of natural gas dew points at Southwest Research Institute, SAI founder Ken Starling served as a consultant in development of the research plan, a role he had previously played in 1985, prior to the dew point and liquid drop out measurements sponsored by Gasunie Research in the Netherlands.

Following the progress of both of these research projects disclosed the need for a reliable method for accurate calculations of dew points for natural gases in operating gas pipelines. The commonly used three step method of sampling, analysis and calculation can encounter undetected errors at each step. Sampling is difficult, accurate analysis is difficult and the resultant calculations of dew point and/or condensed liquid are uncertain.

The method developed and used in PrDewPointV1 is to combine the direct measurement of dew point and the gas analysis so that the hexanes plus portion of the gas analysis is adjusted to match the measured dew point. This adjustment of the portion of the gas analysis which has the largest uncertainty yields calculation results in the region of the dew point which have much lower uncertainty than the commonly used three step method. This method was first presented in the paper “Peng-Robinson Equation of State Natural Gas Dew Points,” by Kenneth E. Starling, AGA Operations Conference, Orlando, 2003.

The calculations in PRDewPointV1 can be accessed in two ways. The user can manually enter the inputs in Excel as in the example below. Using Excel provides tremendous flexibility in choosing inputs and outputs and displaying calculation results.

Click image to enlarge Additionally, the executable program PRDewPointV1.exe, when launched, populates all of the inputs, including the gas composition referred to as “Gas A” in the paper, “Peng-Robinson Equation of State Natural Gas Dew Points,” by Kenneth E. Starling, AGA Operations Conference, Orlando, 2003. The executable program is a Windows-based program which uses the dynamic link library PRDewPointV1.DLL to calculate natural gas dew points and/or determine the hexanes plus component distribution to match a measured dew point. The executable program PRDewPointV1.exe can be launched by clicking “PRDewPointV1.exe” in the PRDewPointV1 folder on the Start | All Programs taskbar. Alternatively, opening the subdirectory folder containing PRDewPointV1.exe and double clicking on the PRDewPointV1 icon will open the PRDewPointV1 application. Either method for opening the PRDewPointV1.exe application will display the following screen.

Buy Now

PrDewPointV1 is a beta version. While it is not yet available for licensing, please try the beta version. We welcome your feedback. Contact us at sai@starlingassoc.com if you are interested in a license purchase.