Open Access
Johnson, Ryan A.
Graduate Program:
Energy and Mineral Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
Committee Members:
  • Andre Louis Boehman, Thesis Advisor
  • Joseph Manuel Perez Sr., Thesis Advisor
  • Sarma V Pisupati, Thesis Advisor
  • Matthew Kropf, Thesis Advisor
  • biodiesel
  • analytical
  • quality
  • alternative fuel
This thesis had as its objective the evaluation of current commercial techniques used to assess and monitor biodiesel quality in industry. It was also essential to statistically determine the reliability of alternative tests as compared to current ASTM testing methods. Biodiesel quality assurance is a major cost issue for many small scale producers, while being a major concern for engine manufacturers. The critical tests for biodiesel fuel quality, defined by BQ-9000, were deemed the most necessary to develop alternative testing methods which would benefit the biodiesel industry as a whole. The commercial analytical methods evaluated in this study include QTA, i-Spec and the pHLip test. In addition, methods based on spectrophotometry, dielectric spectroscopy and ultrasonic velocity were developed and explored as potential methods for assessing biodiesel quality. Of all the tests evaluated, most had the potential of acting as a firewall against poor biodiesel quality fuel, but none were found to be capable of predicting whether the fuel would meet ASTM specification consistently. While the QTA FT-IR rapid testing unit can measure most of the critical parameters designated by BQ-9000, it was found that results for key biodiesel quality parameters did not adequately reproduce ASTM results. Yet, the QTA shows promise for potentially carrying out nearly full-range biodiesel analysis in one test. The other commercial apparatus, the i-SPEC Q-100, showed highly insignificant results overall. While the test claims to have high potential, there were no valid results which indicated so. The spectrophotometer test for total glycerin was found to have mediocre results but has the potential to be a highly inexpensive method to produce reliable results. Dielectric spectroscopy measurements of biodiesel did not establish usable trends, but set the foundation for carrying out experiments in-situ for the monitoring of biodiesel either in the facility or as a standalone method for total glycerin, methanol and free glycerol. The ultrasonic velocity measurements provided potentially accurate data for monitoring the biodiesel reaction, but may be limited by being very feedstock dependent.