Technology Description

Environmental Fuel Research, LLC was recently formed to pursue commercializing a process for converting GTW into biodiesel using Bubble Column Reactor (BCR) technology pioneered by Dr. Cairncross and students at Drexel University. The BCR is robust for converting pure and degraded oils to biodiesel. The BCR removes inhibitory by-product water during the reaction and achieves complete conversion to biodiesel in less than two hours. The crude biodiesel produced can be purified vacuum, short-path distillation to high quality biodiesel.

Potential Environmental Benefits

The GTW to biodiesel process produces a valuable fuel from waste materials while reducing the environmental burden of the waste. GTW is fractionated into brown grease for biodiesel production, wastewater, and solids. The wastewater can enter directly into standard municipal wastewater treatment, and the solids can either be landfilled or fed to anaerobic digesters.


Preliminary techno-economic analysis and life cycle assessment predict both economic feasibility and positive environmental impacts for grease to biodiesel processes; however, the results are highly sensitive to the GTW composition and the energy requirements of the fractionation and purification process stages. When the lipid content of GTW is above ~1%, the energy return on investment (EROI) is better than petroleum diesel and when the lipid content is above 15%, the EROI is better than soybean biodiesel. Improvements in pretreatment and purification methods during this project should improve energy efficiency of GTW to biodiesel.

Expected Results

The overall goal of the Phase I SBIR project is to demonstrate the technical feasibility of producing ASTM quality biodiesel from GTW and evaluate the process uncertainties that may limit commercial feasibility. The following are specific research objectives:

1.         Demonstrate extraction of brown grease lipids from grease trap waste and conversion to ASTM-             quality biodiesel.
2.       Conduct a longitudinal study of the variability in GTW composition and quantity.
3.       Improve existing techno-economic and life cycle models to evaluate commercial feasibility of

4.       Prepare for Phase II SBIR project.