Using any renewable or alternative fuel brings certain challenges, and crude glycerin is no exception! Glycerin burns well, and has a huge potential in the heating fuel market, but some facts should be considered before choosing it as your heating fuel.
There are (or soon will be) nearly 200 biodiesel producing countries, none of which have a very solid market for the crude glycerin byproduct. In the USA alone, 35 of the 50 states have biodiesel plants, and the US crude glycerin production will exceed 65 million gallons in 2009. Thus, crude glycerin may be the easiest renewable heating fuel to obtain! Also, most "backyard" biodiesel makers have substantial stocks of glycerin available.
Generally, glycerin solidifies at lower temperatures, and should be kept warm during transportation and storing. Large storage tanks should contain a heated loop from a boiler or other heat source. Also, the boiler room should be heated to prevent the glycerin from gelling in the fuel lines, fuel filters, and the boiler/furnace itself.
The most obvious emission from burning glycerin is a grey-white smoke, similar to wood smoke. Like with wood, this may be a problem in certain areas, but the smoke could easily be cleaned up with a simple scrubber, soon available from Compuheat.
If burned at low temperatures, crude glycerin may produce acrolein. This only happens if glycerin is not burned properly, at combustion temperatures of 400 to 700 degrees F.(200-300 C.). The MK Glycerin Burner from Compuheat operates with an average combustion temperature of 3000+degrees F. (1649 C.), well above the acrolein formation temperature.
So what else is given off burning glycerin? Dr. William Roberts PhD., Director, Applied Energy Research Laboratory at North Carolina State University has these preliminary findings:
"We have made emission measurements. Of interest: the formaldehyde concentration is about two times higher than kerosene, but still less than 18 ppm. Acetaldehyde is about three times higher than kerosene, but lower at 2 ppm, and acrolein, the one everyone talks about, was below our threshold of 20 ppb. Other emissions were comparable to kerosene."
Unlike petroleum based waste oils, glycerin is totally biodegradable and water soluble. This is a huge benefit, especially during transportation and storage. EPA regulations limit the hauling of petroleum based waste oils to 55 gallons, unless a hazardous material license is obtained. Any spills of waste oil, even if legally hauled, are governed by HAZ-MAT regulations and procedures.
In the United States, there are few (if any) regulations concerning the non-commercial hauling and storage of crude glycerin. Being biodegradable, glycerin spills can be either absorbed or washed away. Even the ash from burning glycerin is water soluble, making the cleaning of heating and handling equipment an easy task.
Please check your local regulations concerning the handling and transportation of glycerin.