While companies are beginning to commercialize technologies and processes that use biodiesel-derived glycerin for products such as polyols, dust suppressants and pharmaceutical products, another more basic potential is beginning to get recognition.

In June’s “Proposed Biodiesel Plant List,” many proposed projects were considering the possibility of using their crude glycerin in various forms as a boiler fuel source in replacement of a No. 4 or No. 6 fuel oil. Rose Patzer, a chemist with the Agricultural Utilization Research Institute (AURI) in Marshall, Minn., tells Biodiesel Magazine that several companies have received permits to burn crude glycerin. Although unable to divulge those companies, she did say they weren’t based in Minnesota.

Working with biodiesel since 1996, Patzer has studied the possibility of using glycerin as a fuel or fuel supplement. One study tested glycerin in wood pellets fueling a wood-burning stove. Analysis didn’t show a significant improvement with the glycerin mixture. AURI has also worked with Minnesota biodiesel producer FUMPA Biofuels in combining feather meal and glycerin for use in beef and dairy diets.

A more recent animal feed trial using glycerin has received national attention. Researchers at the University of Arkansas’ Center of Excellence for Poultry Science recently studied glycerin as a dietary supplement in growing broiler chickens. Poultry nutritionist Park Waldroup initiated the study, which evaluated glycerin in diets fed to broilers of typical market age in litter floor pens.

The study, which Waldroup cautions is strictly preliminary, showed that as much as 10 percent glycerin could be fed to chicks in battery brooders up to 16 days of age. Battery brooders are brooding boxes with wire floors stacked on top of each other to conserve space.

Five percent glycerin inclusion in pelleted feed showed no adverse effect on bodyweight, feed intake, feed conversion or mortality. However, 10 percent glycerin inclusion reduced body weight due to reduced feed flow rate. More information on the study can be found at www.biodieselmagazine.com.

Waldroup and his researchers concluded that glycerin can be used as an energy source for broiler diets. While the results of this study are intriguing, Waldroup cautions they are preliminary and were based on a consistent, clean supply of glycerin.

Butler, Ky.’s Griffin Industries provided the glycerin for the study. Griffin produces 2 MMgy of biodiesel in addition to recycling agricultural wastes. “We have looked for different types of markets (for glycerin),” Conway says. “We are very closely related to the animal feeding industry, so we looked at this some time ago.”

Waldroup is continuing to study glycerin in broiler diets, this time using glycerin provided by Stuttgart, Ark.-based Patriot Biofuels, which began producing 3 MMgy of biodiesel this spring. The second study is determining the effects of 2 percent to 2.5 percent glycerin inclusion in order to more accurately represent real world market conditions. “No one is going to be feeding 10 percent glycerin,” Waldroup says. “If you looked at the typical poultry operation, it’s going to be mixing 4,000 tons of feed per week. It would take a pretty big biodiesel plant to even have enough glycerin to have 1 percent in the diet.”

Waldroup again stresses the consistent quality of the glycerin needed to make it a realistic addition to animal diets. “Everybody wants to give me their glycerin,” he says. “But what are some quality parameters?”

Quality a Cause for Concern
Like biodiesel itself, glycerin quality is an obvious concern for refiners. The quality of crude glycerin is as varied as the process technology available to produce biodiesel, which at times can seem limitless. “The crude glycerin quality from biodiesel operations is all over the map,” Howell says. “While the West Centrals’ are looking at newer uses, smaller companies are primarily focused on just trying to get biodiesel produced.”

Patzer says AURI’s studies varied based on the quality of glycerin. In studies that used glycerin as a fuel supplement, the less pure the glycerin the less energy value. Patzer also warns that incomplete combustion of glycerin can release toxins. “Biodiesel plants generally don’t have purification processes (for glycerin),” Patzer says. “If you’re trying to purify it, you’re adding cost. That doesn’t mean we can’t find uses for it.”

Typically, larger, professionally engineered plants have a more consistent glycerin because they give more attention to cleaning up the by-product. Smaller, self-designed facilities oftentimes don’t pay as much attention to glycerin quality, causing it to suffer, according to Howell. “Companies that refine glycerin aren’t willing to take some of the lower quality glycerin,” Howell says.

He adds he’s heard reports of smaller plants essentially giving away glycerin because of small quantities and varying levels of methanol residue and salts within. Biodiesel Magazine has talked with other small plants that have had to pay to dispose of the glycerin.

As with anything in a capitalist system, it all boils down to economics—dollars make sense. As crude oil prices have skyrocketed, so has the interest in biodiesel production and use. The likewise is true with glycerin, although on a significantly less turbulent timeline. Sure, glycerin prices have fallen, but companies aren’t about to invest until that trend is sustained. Once it does, glycerin stands to become an even more commonly used chemical than it already is.

Glycerin will likely become a substitute for common petrochemicals on the market. “Glycerin may become the next biodiesel,” Howell says. “In three to five years, it will be seen as an environmentally friendly way to replace other competing petroleum products. You’ll see a variety of smaller chemical uses where glycerin can come in and replace other petrochemicals. It will be one of the next chemical platforms, to use U.S. DOE speak, that will become widely available, and people will spend time focusing on it.”

Dave Nilles is a Biodiesel Magazine staff writer. Reach him at dnilles@bbibiofuels.com or (701) 373-0636.

View Sidebar Articles

<-- Previous Page	1   2
View Entire Article