Materials

Microscopic sponge turns dirty cooking oil into biodiesel on the cheap

A closeup view of the micron-sized sponge
RMIT University
A closeup view of the micron-sized sponge
RMIT University

Scientists at Australia’s RMIT have developed a tiny sponge with big potential, and say the micron-sized material can be used to convert discarded cooking oil into biodiesel in a very cost-effective manner. And the catalyst is no one-trick pony, with the ability to also turn other waste products into valuable building blocks for a range of materials.

The sponge-like material is a new type of ultra-efficient catalyst for turning complex molecules into raw materials. The RMIT team behind it actually describes it as the first of its kind, in that the ability to carry out a series of different chemical reactions within the one material while offering a high degree of control over the output is unprecedented.

"Catalysts have previously been developed that can perform multiple simultaneous reactions, but these approaches offer little control over the chemistry and tend to be inefficient and unpredictable," says co-lead investigator Professor Karen Wilson. "Our bio-inspired approach looks to nature's catalysts – enzymes – to develop a powerful and precise way of performing multiple reactions in a set sequence. It's like having a nanoscale production line for chemical reactions – all housed in one, tiny and super-efficient catalyst particle.”

The sponge-like catalyst is micron sized and highly porous. When molecules are fed into the sponge, they undergo a chemical reaction in the large pores and then make their way into the smaller pores, where a second chemical reaction takes place. The process is not only cheap, but can make use of low-grade ingredients that would otherwise be destined for the scrapheap.

Among those is cooking oil, which currently needs to be cleaned thoroughly in an energy-intensive process to rid if of its contaminants before it can be turned into biodiesel. The approaches in use today can only handle feedstocks with 1-2 percent contaminants, whereas the durable new process developed by the RMIT team can handle feedstocks containing up to 50 percent contaminants.

The researchers ay that in its current form, the catalyst can turn these types of low-grade feedstocks into low-carbon biodiesel using basically just a large container, along with some gentle heating and stirring. With further work, the technology could be adapted to produce jet fuel from agricultural waste, rubber tires or algae.

Additionally, the efficiency of the technology could double the productivity of processes currently used to produce chemical precursors for a wide variety of products, such as medicines and packaging, from food waste, tires and microplastics.

From here, the researchers are working to scale up the process for larger output, with an eye on commercialization.

"Our new catalysts can help us get the full value of resources that would ordinarily go to waste – from rancid used cooking oil to rice husks and vegetable peelings – to advance the circular economy," says co-lead investigator Professor Adam Lee. "And by radically boosting efficiency, they could help us significantly reduce environmental pollution from chemical manufacturing and bring us closer to the green chemistry revolution."

The research was published in the journal Nature Catalysis.

Source: RMIT via EurekAlert

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6 comments
FB36
Just think about how a truly massive number of vehicles exist all over the world (like trucks, ships, trains, agricultural machinery, ...) which run on diesel fuel!!!
Imagine how much help it would be for GW, if humanity started producing tons of bio-diesel, from all kinds of waste/biomass from industry & agriculture & forest cleanup!!!
Jacksdad
Fillerup at the Golden Arches!
Username
Why catalysts? What process? I have friends who ran a bus on used cooking oil and the only thing they did was filter it to get rid of fried food bits. They managed to make it to Costa Rica and back on discarded restaurant oil they got for free along the way. But more importantly, what is the exhaust produced with bio-diesel?
McDesign
I have a car that runs on waste vegetable oil (WVO); a 1959 Mercedes 190D that ran the 2008 La Carrera Panamericana race; all thousand miles on begged restaurant waste oil. The mechanical injection system has not been modified; a stand-alone second fuel system has been added with some solenoids for switching between.

The WVO simply requires settling/filtering for the water and debris. The car does have two fuel systems, so it starts on diesel, then is manually switched to the water-heated WVO system when it's warm enough to pump. You most switch back to diesel to clear the system before turning off the engine.

This is not biodiesel, which by definition can run in any diesel car with no mods. To make biodiesel, you precipitate out all the glycerine with lye, then add back the equivalent volume of methanol (which is expensive).

Given this above, not sure what the guys in this article are doing
jerryd
Sorry but BS. catalysts are set up for certain feedstocks for certain outputs. You can't just use one for all.
Eddy
Not sure I would be game to put it in my ridiculously high-pressure fuel system with the current cost of pumps and almost no tolerance injectors even with my 1 micron post filter.