Laughing Stock Farm, Freeport, Maine

Project Tour
Grant Abstract
Final Report

Grant Project Overview

Over the last five years I have researched what energy options may be available to a small greenhouse producer like Laughing Stock Farm on the southern coast of Maine for heating greenhouses using local biomass.  The best solution currently available is the direct burning of restaurant used cooking oil (UCO) in commercially available waste oil burners.

The most logical option up to now has been wood.  We live in a densely populated area of the state and cannot afford a woodlot.  Also, wood is a fairly dirty and labor intensive fuel.  We do not believe that the state's problems could be solved if everyone burned wood because of the high particulate and other emissions from wood furnaces and boilers.  It's true that wood is a renewable non-fossil carbon fuel, but as anyone who has had a wood stove knows, it makes lots of smoke.  Still, though it will not work for us in Freeport, wood remains a good viable solution for areas of the State where no better options exist. 

Another option is Biodiesel which is typically made from surplus soy oil, but can also be made from UCO.  We have strong supplies of UCO in Freeport relative to our energy use.  In our research we learned that hazardous materials are used to make biodiesel, that the process is not as simple as some would have you believe, and that the glycerol byproduct must be disposed of because it is too contaminated with impurities to have any economic value.  To make 100 gallons of biodiesel, you loose 15 to 20 gallons of UCO as wastes and glycerol byproduct and you need to use 30 to 40 gallons of methanol, which is a hazardous material.  Finally, it takes about 500 gallons of fresh water to wash impurities from a 100 gallon batch of biodiesel.  That water then must be disposed of properly.  That's a lot of waste and a lot of hazardous material.  There must be an easier way...

Direct burning of the UCO became an option when I found two companies who make commercial sized waste oil burners for automotive waste oils and who certify that their burners will burn vegetable oil.  Industrial users of vegetable oil, like McCain's in Aroostook County, have burned their UCO in industrial boilers for years.  Most commercial waste oil burners will not accept UCO because of the glycerin content of the WVO, which is the same reason it cannot be burned in compression ignition engines.  It clogs and cokes the internal components in a very short time.  It also has a flash point of about 400 deg F, making it extremely difficult to completely burn.  While most waste oil burners use compressed air to assist in atomizing the waste oil for better combustion, and a small heater block to make sure the waste oil stays liquid during the flow and atomization, the system we are now using includes a ceramic inner chamber and target to provide a surface at approximately the flame temperature thus assuring complete combustion.  After one failed attempt using another system, the Clean Burn system we are now using has become our preferred option because it works.

The best estimates are that about 1,500,000 gallons of UCO are hauled off every year from restaurants in Maine.  It is not clear to me why some in Maine are so strongly advocating that we ship in 300,000 to 400,000 gallons of hazardous methanol from outside the state when the purpose of the methanol is to throw away 250,000 gallons of (gycerin) usable heating fuel.  That amount of UCO contains about 3.3 trillion BTUs.  Not as big a number as the national debt, but clearly making biodiesel from Maine's UCO is not the most energy efficient way to use the limited UCO resource we have in Maine.  

Send mail to lisa@laughingstockfarm.com with questions or comments about our farm

Send to ralph@rturner.com with questions or comments about our energy project. 

Copyright 2008, Laughing Stock Farm
Last modified: February 01, 2008