Home Made Bio-Diesel Harder Than Looks

INDIAN HEAD - Nov 7/07 - AAFC -- The past two years have been filled with optimism regarding the use of vegetable oils from crops like canola as a partial replacement for diesel currently derived solely from fossil fuels. This optimism has also been reflected in higher prices for vegetable oil which is welcomed news for all producers.

There is also an assumption being made that producers, with a small investment, can get into the production of bio-diesel with relative ease and meet some of their fuel needs. After doing a bit of reading and talking to people in the know on this topic, it might be a bit more complicated than at first glance.

There are currently two main production methods that I know for bio-diesel. The first method uses vegetable oils, waste cooking oil, animal fats or tall oil. Tall oil is a waste product originating from the pulp and paper industry. Before these oils can be blended with existing diesel fuel, they have to be transesterified. The process involves chemical reactions of the oils with methanol and sodium hydroxide. The end product is glycerine and bio-diesel. This chemical process makes the resulting oil less viscous and sticky. Additives are also included to minimize problems with cold flow properties during the winter months. The resulting biodiesel is then blended with existing diesel in different proportions. In certain countries, they use 100% biodiesel.

For more details, please refer to the following website http://oee.nrcan.gc.ca/transportation/fuels/biodiesel/biodiesel.cfm or simply do a search on the internet using the word 'biodiesel'.

The second method of bio-diesel production involves using straight vegetable oil (SVO). Using a crop like canola for example, you would simply crush the seed, extract and filter the oil.The oil is then ready to be used as a fuel. However before the oil can be used in the engine, it needs to be heated to 70-80 degrees C before injecting into the combustion chamber.

The current recommendation is to start the engine on regular diesel and when the engine is warm enough to heat the oil to the desired temperature, you switch to SVO. It should be noted that some hardware is required to make this happen. Before turning the engine off, you would switch back to regular diesel and then shut the engine off. For more information, please consult the website http://www.plantdrive.ca/.

The SVO method is a much simpler process than the first one and can be done for a very low cost making it very enticing for people interested in making their own on-farm fuel.

So why do we need to approach the on-farm manufacture of bio-diesel with caution?

The first point of concern with the bio-diesel derived from the chemical process involving transesterification, is the ability to meet stringent quality standards so that engine warranties are not voided. There is also the issue of meeting emission standards, horsepower and fuel efficiency relative to regular diesel. The other issue is the cost of testing to make sure that the required standards are being met with each batch of bio-diesel. For many on-farm operations, these testing costs alone make it virtually uneconomical.

With the SVO system, the main objections have to do with longevity of engine life, fouling of fuel injectors and failure of fuel pumps. Vegetable oils that are circulated and heated repeatedly, which would be the case for most diesel engines, can slowly modify chemically and potentially increase fouling of the fuel pumps.

Another important issue is warranty on engines with this type of product. You are basically on your own with this one. There are mounting voices against the use of SVO as a bio-diesel for the reasons discussed. More recently, some people are now starting to question the economic viability of biodiesel due to the rising cost of vegetable oil. Before you venture down this road, take your time to inform yourself to make sure you know what you are getting yourself into. Due diligence is in order before signing the check to set up your own biodiesel facility.