Mustard passes muster in industrial applications

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Mustard oil-based biodegradable cleaner/degreaser formulated by Cigi.

Cigi has discovered that mustard oil as a biodiesel product (methyl ester) is feasible for use in a number of industrial applications, thanks to funding from Mustard 21 that allowed for investigative work over a six-week period.

A series of existing and newly developed tests conducted last November and December indicated that mustard biodiesel would work well as a base stock in formulations for cleaners/degreasers, penetrating oils, concrete form release agents, solvents, and also for limited use in fuels.

“We had been promoting mustard for a couple of years, made some biodiesel product that we were happy with, and had talked to some biodiesel plants about using it,” says Dr. Rex Newkirk, Cigi Director of Research and Business Development. “Funding from Mustard 21, a Canadian organization looking to enhance markets for mustard, gave us an opportunity to look at a broader range of uses with some scientific evaluation.”

He says another company Cigi has worked with, Eastern Greenway Oils, connected him with Mustard 21. What followed was development of a general purpose product, a penetrating oil that came about from dealing with drips in the Cigi biodiesel trailer that were found to loosen rusty tools.

“We had to set up a test, come up with a method to do a side-by-side comparison with commercial products,” Rex says. “So we crafted half-inch pieces of steel rod and inserted a pin into a small hole we bored in the rod. We then rusted the rods and the pin inserts with a solution and used our TA.HD texture analyzer to measure the force it took to push the pin out. The mustard biodiesel performed better than some commercial products which gave us a basis to say it would work well as a base stock for use in formulating a penetrating oil.”

Rex says that as a cleaner, mustard biodiesel “was too effective,” actually cleaning grease off a plate in one wipe. Therefore, a standardized test was modified, using more difficult greases – a blend of lard, shortening, and carbon black – to create graded levels for measurement of effectiveness. He built a linear tabletop cleaning machine with three lanes, each having a 100-gram weight placed on a sponge soaked with cleaner. White tiles were plastered with the grease, the sponges were pulled across each of them in four passes, and then the tiles were analyzed with a colour metre.

“In some ways the mustard worked better than commercial cleaners,” he says. “It is ideal as a non-toxic product, great especially as a cleaner for food products, like frying oil, rather than using a nasty (toxic) solvent.”

As far as determining the effectiveness of mustard biodiesel as a solvent, an old established test called the Kauri-Butenol method was used which measures the ability of a solvent to dissolve gum from a kauri tree. Rex says that although mustard oil had low solvent strength, the two mustard biodiesel samples were effective as a medium-strength solvent, making them good for cleaning items such as paint brushes. “Mustard methyl esters are not as strong as a more aggressive substance like xylene, but have an advantage over petroleum-based solvents in that they are biodegradable and environmentally-friendly.”

Evaluation of the mustard biodiesel as a concrete release agent also involved the creation of a test with the texture analyzer, he says. “We came up with tests out of necessity. In this case when concrete is poured you have to remove the forms around it before it sets or some of the cement surface will adhere and come off. So you need something to make it slip away easily. Usually something more toxic like diesel fuel is used which also soaks into the ground.”

 For the test he added a rig to the texture analyzer to pull the cement away from the form and data on the force required was recorded on a computer. The results showed the two mustard biodiesel samples were as effective as other commercial products, making mustard oil-based methyl esters feasible for use in the formulation of high-quality, non-toxic, non-flammable release agents.

Rex admits that as a biodiesel fuel, mustard has limitations. Testing by an external source indicated it doesn’t meet the standard distillation temperature required in which 90 percent of the oil is boiled off, so it would be unacceptable as a biodiesel blend stock in North America. He explains that mustard oil doesn’t boil off at a low enough temperature because it is a very long-chain fatty acid. However, it still has potential as a feed stock for biofuel production when combined with other oils.

 “Mustard 21 seemed happy with our results which showed that mustard biodiesel has good potential in the formulation of a number of commercial products,” he says.

 For more information: rnewkirk@cigi.ca or go to mustard21.com

 Article originally published in Cigi.ca e-publication, Spring 2011.