This project has focused on very low grade fats, oil and greases found in municipal, commercial and industrial facilities around the country. These wastes are often disposed in landfills, wastewater treatment plants or farm fields or are blended illegally into animal feeds. Using any of these waste fatty materials that are unfit for human or animal nutrition as a clean alternative fuel makes good sense. This project defines the aforementioned wastes in terms of quality and prevalence in the US, then builds on specific promising pathways for utilizing these carbon neutral wastes. These pathways are discussed and researched at bench-scale, and in one instance, at pilot-scale. The three primary pathways are as follows: The production of Renewable Diesel Oil (RDO) as a stand-alone fuel or blended with standard distillate or residual hydrocarbons
The production of RDO as a platform for the further manufacture of Biodiesel utilizing acid esterification
The production of RDO as a platform for the manufacture of an ASTM Diesel Fuel using one or more catalysts to effect a decarboxylation of the carboxylics present in RDO This study shows that Biodiesel and ASTM Diesel produced at bench-scale (utilizing RDO made from grease trap waste as an input) could not meet industry specifications utilizing the technologies that were selected by the investigators. Details of these investigations are discussed in this report and will hopefully provide a starting point for other researchers interested in these pathways in future studies. Although results were inconclusive in finding ways to utilize RDO technology, in effect, as a pretreatment for commonly discussed technologies such as Biodiesel and ASTM Diesel, this study does shed light on the properties, performance and cost of utilizing waste greases directly as a retail liquid fuel (RDO). The utilization as a retail RDO as a boiler fuel, or for other such applications, is the most important finding of the study.