Animal Fat Biodiesel
Great news on the sustainability front for the western hemisphere: USA produced biodiesel is increasingly coming from rendered animal fats – 20% in 2008 to over 30% in 2009 (Click here for a chart from the National Renderers Association). Canada is ahead of us because of the 2003 Mad Cow Disease and 2005 Bird Flu – 90% of Canadian biodiesel comes from animal fat. I am thrilled to discover the market is growing fast toward the best fuel for today’s engines. Click here to see a potential new refining technique. Why is it the best? It is the most sustainable, provides the most power, is the most efficient, and has the least emissions of any biodiesel, diesel, gasoline or ethanol (I have not looked into algae based biodiesel or compressed natural gas yet). Oh, and it should go without saying that when purchased from a licensed distributor, animal fat based biodiesel meets the ASTM-D6751 fuel standard and therefore is a certified diesel fuel and cannot void engine manufacturers warranties.
The Most Sustainable:
Rendered animal fats are a by-product and do not compete with human food production or any agricultural land. Thus they are cheap as the market for them is primarily feed for hogs and pets. According to the US Census Bureau, 4.6 million metric tons of rendered fats are produced each year, and according to the USDA, animal consumption is expected to rise at a 1% rate. Currently around 8% is being turned into biodiesel in the USA yielding over 100 million gallons – if all the greases and tallows were used it would be 1.5 billion gallons – see Sanimax Energy’s Jeremy Goodfellow’s work in Biodiesel Magazine (2009), and the Sanimax Promo Slide Deck (2008). Other resources are the National Biodiesel Board and the American Oil Chemists Society.
The Best for Modern Diesel Engines:
Just like vegetable oil based biodiesel it has superior lubricating qualities compared to ultra-low sulfur diesel thus prolonging engine life. It has the highest cetane number of any diesel fuel – meaning it ignites quickly providing maximum power per unit volume and minimizing emissions. It has a higher energy content than vegetable oil based biodiesel (which is slightly less than petroleum diesel) but it is not clear if it is greater than petroleum diesel. Finally, the saturated fats make it more stable than veggie-biodiesel giving it a longer shelf life.
From Frozen Fat to Biodiesel:
The one drawback is it’s high cold filter plug point requiring care be taken in cold climates (much like vegetable oil based biodiesel). Just think about how think it can be at room temperature. The first Thanksgiving I had my grease-car we had a ham with my cousin in Boulder and there was almost a whole pint of fat that dripped out. I took it home in a jar to keep for a couple weeks while the water and seasonings fell out. That was not as easy as I expected having done it with vegetable oil because when it cooled it became solid pig jello. I had to put the jar in a pot of hot water to liquefy it but I poured it into my tank anyway testing my system which heats the fuel up to nearly the temperature of the coolant via a GoGreenEarly aluminum filter housing. No luck however – it clogged 2 set of filters over that December.
This last summer I saved all the lamb, beef, and pork fat from the roasting pans after dinner and collected about a quart/liter to make biodiesel out of it. In the heat of the day in August it would be liquid and at night would freeze into what looked like yellow shortening. After raiding the medicine cabinet I found rubbing alcohol and some cups that held 50 mL with graduations on the side. All I needed to order on-line was methanol, lye, and a couple indicators to make biodiesel, wash it, test for complete reaction, and test for soap.
I spent about $20 and can make about 2 gallons of biodiesel – next 2 gallons will only cost for the methanol – a 5 gallon bucket will make about 20 gallons of fuel for $45.