Golden Meniscus Quality

quality control decoded

By Kumar Plocher

More in the Fall 2009 issue

In order to know which fuel quality tests you need to perform, and how frequently you need to perform them, you need to know what your goals are.
In the case of Yokayo Biofuels, our goal is twofold: to maintain our ability to be within the specifications of the ASTM standard, so that we can legally sell fuel, as well as to generate records for certain high volume customers that require them. I do a number of tests daily on site, and supplement those with other less frequent tests from third party labs.
Your goals may be quite different.
In some cases, the goal is as simple as "I want to make sure that the fuel I produce doesn't wreck my old Mercedes." If that is your goal, your quality program may be as simple as a heat-and-weigh water test, a "27/3" methanol solubility test for conversion, and a soap titration.
One myth that I hear is that "bigger is better," i.e. commercial producers make better fuel than homebrewers. Personally, I've seen bad fuel from both, and while commercial producers may have a cash advantage when it comes to buying certain equipment, homebrewers can get to know the fuel on a much deeper level. I think a motivated, careful homebrewer can easily hang with the big dogs on quality control.
Another myth I hear all the time is that biodiesel fuel can be "ASTM certified." While it is true that the organization originally known as the American Society for Testing and Materials does endorse certain labs for performing specific ASTM tests, there isn't any ASTM seal of approval that can be stamped on fuel the way that a "certified organic" label can. ASTM publishes the frequently-updated biodiesel standard (current version is D6751-09), which is comprised of test methods and the results that will keep you "in-spec."
Another misperception out there is that every batch of commercial biodiesel has every ASTM test done on it. While that wouldn't be a bad idea in theory, in reality that approach is cost prohibitive for most producers, who choose to focus on the "most important tests" more frequently than the whole entire slate.
The National Biodiesel Board created the "BQ9000" protocol to provide the framework for successful quality control programs. However, it is designed for big commercial producers, and some of the requirements may seem less functional and overly expensive to smaller producers.
As a homebrewer or small producer, you may want to gather information about BQ9000 just to have a template to follow.
Some important things to remember in designing a quality control program:

+ in order to have proper accountability, some individual must be the designated quality-control-responsible party
+ for test results to be relevant, you should have a standardized sampling protocol (e.g. "inline" or "bottom-middle-top") that gives representative results
+ hard copies persevere, so there must be a secure paper trail of quality control
+ in order to address possible future concerns, samples must be kept for an appropriate period of time, and stored appropriately
+ third party labs must be used to double-check your results
+ sampling and testing must include the entire chain-of-custody until the fuel reaches the customer

What's good fuel today might not pass as good fuel tomorrow. As we've seen with the emergence of diesel particulate filters, new technology can change the rules of the game.
Staying abreast of the latest ASTM and international standards (see European standard EN 14214, for instance) can help you be current in your fuel quality, as can keeping up with the latest news on engine development and homebrew innovations.

Kumar Plocher is founder and president of Yokayo Biofuels in Ukiah, CA. He blogs at ybiofuels.livejournal.com