Report
PURIFICATION OF BROWN GREASE FOR FUEL PRODUCTION
30 Jan 2020
Abstract
During the performance period for this research project, four grease byproducts with elevated sulfur and Free Fatty Acid (FFA) content were reduced to relatively pure FFA in order to increase their viability and value, primarily for biodiesel production. These greases were Distillers Corn Oil, Poultry Brown Grease, Tallow Brown Grease and Grease Trap Waste (GTW) from a regional wastewater treatment plant. Sulfur content of the brown greases ranged from 7 – 190ppm and Total Acid Number (TAN) ranged from 8 – 179. Both GTW and Tallow brown grease (BG) had long residence times in waste-water streams, resulting in large quantities of emulsified water as well as suspended particulates. Because the brown grease, lipid mixture already contained a high percentage of FFA, we approached the issue of inconsistency as resolvable by reduction, as opposed to restoration; e.g. as opposed to glycerolysis, converting FFA into mono and diglycerides, we reduced the remaining glycerides in the mixture to FFA. The resulting mixture of predominantly C16 and C18 FFA was then treated as one distinct material. The lipids were reduced by hydrolysis, yielding FFA free of soaps and insolubles, allowing exploration of methodology for desulfurization of the bound sulfur species alone. Two purification stages were expected to be required, the first for removal of color bodies, insolubles and easy-to-remove sulfur contaminants with desulfurization to approximately 50ppm or less. A secondary polishing stage would be used for deep desulfurization to levels required in the ASTM D6751 specification of 15ppm or less. Primary purification proved to be generally effective at desulfurization to levels of <15ppm with yields of approximately 80 – 90%. Secondary purification via adsorbents would achieve desulfurization to 0.6, 1.7, 1 and 20ppm with one pass, at room temperature and pressure. The resulting FFA is light in color and is relatively consistent regardless of its original source. At the time of this writing, EFR has already begun to engage biodiesel producers and adsorbent manufacturers to begin the process of moving this research from the laboratory to commercial production.
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Details
- Title
- PURIFICATION OF BROWN GREASE FOR FUEL PRODUCTION
- Creators
- Donald Joseph WilsonRichard Allen Cairncross - Drexel UniversityEnrironmental Fuel Research, LLC
- Publisher
- United States
- Resource Type
- Report
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Identifiers
- 991019295188004721