Passion Fruit, Moringa and Thistles: Biolubricants of the Future?

It is estimated that the world consumes about 40 million tons of lubricants per year, of which about 40 to 50 percent end up in the environment. The much evidenced toxic impact of petrochemical lubricants does make a strong case for the use of bio-based lubricants, which unfortunately still constitute a very small portion of the global lubricants market. But that’s beginning to change.

The global biolubricants industry received its first major push two years ago when the U.S. Environmental Protection Agency (EPA) brought the environmentally acceptable lubricants (EALs) regulation into force. Since then, there has been considerable interest in the development of biolubricants not just for marine vessels, but also for other industrial and automotive applications.

More importantly, the potential sources for base oil for lubricants now span a wide range. Although scientists have studied palm oil, soybean oil, cottonseed, sunflower, canola and mahua as base oil candidates for bio-based lubricants, new projects involving passion fruit seeds, thistles and even waste cooking oil could bring more variety to the global bio-based lubricant market.

Passion fruit and moringa oil

At the Federal University of Rio Grande do Norte in Brazil, researchers’ interest in passion fruit was whetted by the fact that about 85 percent of passion fruit seed oil is composed of unsaturated fatty acids. Similarly, moringa seeds are oil-rich, and have the same percentage of unsaturated fatty acids as passion fruit seed. Moringa has become quite the rage in the cosmetics and super foods industry, but its excellent thermo-oxidative stability and high oleic acid content (74 percent) make moringa oil a promising candidate for bio-based lubricant formulation, too.

As part of this study, researchers set out to experiment with hydraulic biolubricants using vegetable oils epoxidized via performic acid. They found that the two seed oils – modified using the epoxidation technique – displayed desirable tribological properties, which means that the two seed oils can replace commercial mineral-based lubricating fluids.

Sardinian thistles

In Europe, an estimated 3 million tons of petrol-based lubricants end up in the sea. But cardoon, a thistle-like a plant related to the artichoke, could herald a new chapter in biolubricant formulation. Italian company Matrica has been using cardoon seed oil to make bioplastics – but it says the oil can also be used for manufacturing biolubricants that perform at par with conventional lubricants. The advantages of lubricants formulated using cardoon seed oil as the base are that they dissolve in the sea, polluting neither water reserves nor the soil.

Using indigenous plants to explore their ability to serve as biolubricants seems to be the trend in the research fraternity. Just as thistles grow copiously in Europe, jatropha and neem trees are found in abundance in Southeast Asia. With industrial activity having gathered steam in the region in the last decade, several researchers have been working on formulating biolubricants using neem and jatropha seeds.

Could waste cooking oil lubricate vehicles and machines?

Producing biolubricants from scratch using plant seeds is one facet of the trend. Many research institutions are also looking at ways to convert waste cooking oil into biolubricants by subjecting it to innovative purification processes.

Researchers at the Chinese Academy of Sciences have explored this possibility, as has Bioprocesa Technologies, a company working in collaboration with the University of Granada’s Chemical Engineering Department. The latter’s research has shown that it is possible to convert used vegetable-based cooking oils into eco-friendly lubricants. The patent-pending technology will help extract the last bit of value from vegetable oil after it has been used in the kitchen. What remains to be seen is how commercially-viable this idea turns out to be.

They will likely not have a revolutionary environmental impact anytime soon, but biolubricants are finding takers. This can be gauged from the fact that by 2030, about 15 percent of all lubricants used worldwide will be biolubricants. Reaching this figure doesn’t seem like a herculean task – efforts are already afoot in various parts of the world to harness indigenous flora to formulate plant-based lubricants. However, they will continue to be a niche area until their price, performance and availability reach an equilibrium.

Image credits: 1) Pixabay 2) Flickr/Janaína de Oliveira

Having extensively worked as a journalist with leading national dailies in India, Anuradha Wadhwani now writes for Transparency Market Research, a market intelligence firm. Anuradha is passionate about tracking (and questioning!) market trends across areas such as sustainability, innovative materials, and chemicals.