Researchers have shown if you want your diesel car or truck to run more smoothly, it's best to add biodiesel produced from the seeds of an Aussie native plant known as the ‘Beauty Leaf Tree'.

The CQUniversity scientists have patented the seeds-to-oil conversion process with a view to commercialising their ‘anti-knocking' agent for diesel fuel.

Researcher Subhash (right) and Ashwath pictured with a Beauty Leaf Tree beside a 4WD engine

Using a Land Rover Freelander 3.5L engine, tests were carried out using commercially available petrodiesel and biodiesel blends, and the results were compared with those obtained from petrodiesel fuel mixed with the beauty leaf product known as Calophyllum Oil Methyl Ester (COME)*.

"The beauty leaf blend can significantly reduce vibration and knock in diesel engines, indicating better ignition properties and greater smoothness of the combustion," said Associate Professor Nanjappa Ashwath, one of the researchers involved.

"Further tests are required to determine the optimum percentage of biodiesel that gives the best reduction in vibration."

PhD scholar Subhash Hathurusingha has been undertaking this research under the supervision of Assoc Prof Ashwath and Professor David Midmore. Subhash plans to progress the project as a post-doctoral research fellow.

PhD scholar Subhash Hathurusingha and Assoc Prof Nanjappa Ashwath with a Beauty Leaf Tree growing on campus

Assoc Prof Ashwath says that, apart from the undesirable mechanical effects of diesel knock, the extra noise also leads to sound pollution.

"Extensive engine vibration wears engine components and causes an irritating noise," Subhash says.

Earlier testing by CQUniversity scientists has indicated that the wild-growing beauty leaf tree is a potential source of biodiesel, if developed into plantations. It can produce up to 4000L of oil per hectare in a year.

"The beauty of the Beauty Leaf Tree is that it grows well throughout coastal areas of tropical Australia and can thrive on salty, drought-affected, acidic or waterlogged lands, which would otherwise remain unused," Assoc Prof Ashwath says.

* Previous vibration tests were done with the help of Dr Jayantha Epaarachchi (USQ), Amila Jayaratne (Rockhampton Hydraulics) and Dr Preethichandra Gamage (CQUni).

Further details on the tree growth potential can be obtained from Assoc Prof Nanjappa Ashwath (0419 309 596). Details on engine performance may be sought from Subhash (0420 743 462) or Dr Jayantha Epaarachchi (0402 455 823).