Biodiesel for Bioheat

Long time readers of our site may remember that we brew our own biodiesel for two of our diesel powered cars. What they (and our new reader friends) might not know, is that we use that same homebrewed biodiesel for bioheat. Our boiler's oil tanks have a capacity of 550 gallons, so we brew-up 110 gallons of biodiesel and add that to our tanks and then have a delivery of heating oil (about 440 gallons) added to make a bioheat blend of B20. What's bioheat? Well, it's a term coined to describe biofuel used, not to power vehicles, but to power oil-fired heating equipment--mainly furnaces and boilers.

And just as biodiesel acts like a detergent in a vehicle's fuel system, bioheat behaves the same way in an oil-fired heating system's fuel plumbing. Heating oil and diesel fuel both leave a build-up of residue in tanks, fuel lines and pumps that is loosened and scoured away by biofuel when it's introduced to an already-in-service system. The fuel-oil filter is the first line of defense to protect an oil burner's pump and fuel nozzle. In most systems, this is a wool or paper fiber element located within a steel housing of fairly small capacity. Depending upon the severity of residual deposits in the fuel system, these small capacity filters can become clogged quickly. Additionally, reliant on quality of media material, the filter's integrity can be compromised by the scrubbing effect of bioheat fuel.

Central Illinois Manufacturing Company has developed a line of synthetic filter elements specifically designed for use with biofuel blends as well as pure B100. We had the opportunity to test one of these filters, Blu-Flame model #70966, for an entire winter heating season. We installed this filter in October 2007; this high capacity unit has a vacuum gauge that indicates when it's reached capacity. As winter winds down, our gauge still shows that the filter has much of its capacity remaining, and while we're going to get a replacement filter, Scott first wants to see if we can get another season out of this one.