A Measurement Process for the Determination of the Mixture Averaged Molecular Weight of Complex Mixtures

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A Novel Measurement Process for the Determination of the Mixture Averaged Molecular Weight of Complex Mixtures

Princeton Docket # 12-2788-1

Researchers at Princeton University have developed a new process to determine the mixture averaged (or apparent) molecular weight of complex mixtures, specifically for liquid fuels, including automotive fuels, jet propulsion fuels, and rocket propellants.

Mixture averaged molecular weight is a required quantity for the on-highway vehicle engine emission certification process. As calculated using current methods, the mixture average molecular weight is an assumed quantity, resulting in uncertainties in the calculated emission levels. Measurement of the mixture averaged molecular weight is also critical for the characterization of refinery petroleum distillate fractions. Currently, the methodologies used are mostly based on empirical correlations of mixture boiling point, fluid viscosity and other parameters, which limit accuracy. 

The novel measurement process developed by researchers at Princeton University has major advantages over the currently employed methods, such as vapor pressure osmometry, freezing point suppression, and gas chromatogragraphical-mass spectrometer analysis. It is simple, low cost, fast, uses no exotic equipment, and provides a significant improvement in accuracy. The test time is less than five minutes for each complex mixture, and is accurate to at least ± 1 g/mol. The process also only requires very small mass of the analyte, and no calibration procedure is required. The simplified nature of the process allows it to be readily automated. Furthermore, the process is appropriate for analytes of all phases and it is not restricted by the solubility of the analyte.

It is anticipated that this technology can be applied to provide an automated platform for simple and accurate measurement of the mixture averaged molecular weight of liquid fuels, including automotive fuels, jet propulsion fuels and rocket propellants. It also has application potential in characterization of different composite molecular materials, including polymers, solvents and chemical reagents used for organic synthesis.

The Faculty Inventor

Frederick Dryer is Professor of Mechanical and Aerospace Engineering at Princeton University.  His principal research interests include: The production and interaction of next generation transportation and power generation fuels, including, fossil derived fuels such as jet aviation fuels, petroleum, syngas and natural gas as well as alternative and bio-derived fuels such as Fischer-Tropsch fuels, biodiesels and bio-alcohols. The laboratory is focused on the role of these fuels and where relevant, mixtures of these fuels in addressing greenhouse gas and other pollutant formation issues in addition to their ability to impact U.S. energy security concerns.

Intellectual Property status

Patent protection is pending and a working prototype has been developed.

Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.


Michael Tyerech

Princeton University Office of Technology Licensing

(609) 258-6762  tyerech@princeton.edu


Patent Information:
For Information, Contact:
Chris Wright
Licensing Associate
Princeton University
Frederick Dryer
Sang Hee Won
Stephen Dooley
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