Clearing the Way for Byproduct Quality
by Bryan Sims (Biodiesel Magazine) Why quality for glycerin is just as important for biodiesel
…With all the stringent quality measures imposed on producers, there is, however, no governing body that imposes or oversees similar quality standards for crude glycerin, the byproduct that’s left at the end of the transesterification process.
…Remaining contaminants such as methanol, soaps and water can render the composition of glycerin to consist anywhere between 40 and 80 percent pure glycerol, depending on the feedstocks and processes employed.
Because of the these differences in purity levels, crude glycerin is viewed as a highly variable commodity from plant to plant, making it difficult for a regulatory body or standards committee to impose any kind of uniform quality standard across the board, says Mark Rice, CEO of Northbrook, Ill.-based chemicals and fuels testing firm Biofuels Technology LLC.
“Quality of crude glycerin has to do with everything from the weather to the feedstock that they’re using, to the plant manager who’s on shift, so the glycerin byproduct is very inconsistent and, for the most part in the U.S., is very poor quality,” Rice explains.
…While some biodiesel producers refine their crude glycerin to technical grade, the majority of them can’t afford it and are left having to dispose of it according to regulatory requirements or sell it at a very low price—between 1 and 8 cents a pound in some cases. Because of its low value, crude glycerin is sometimes used as a dust suppressor on roads or burnt for energy even though its Btu value is low. Interest, however, in finding other applications for crude glycerin, such as a supplement for animal feed, is on the rise.
…“If biodiesel plants are selling to people that don’t know what they’re doing and don’t handle their glycerin in a safe and ethical manner, it could come back to bite them in a really bad way,” Rice adds. “Understanding the technicalities of glycerin, where it goes and knowing the composition of it is very important and often overlooked.” READ MORE
