What do you do with the oil you used to cook dinner?  Perhaps you haphazardly swirl it around with soap and dump it down the drain, or you meticulously collect it in a container only to throw it in a trashcan.  These are the most common approaches to handling the aftermath of a greasy meal, but a team of researchers from Toronto, Canada is adding a third option to the dinner table.

Why not turn that oil into resin for 3-D printers?

A perfectly logical next step, and a sustainable one at that!  Disposing of used cooking oil by washing it down the drain can cost communities a hefty sum to repair the sewage lines that clog from fat build-up, but proper disposal methods used by restaurants such as McDonald’s aren’t any cheaper. 

In 2014, France was estimated to spend over 540 million dollars in the collection and transportation of waste cooking oils. 

However, by recycling the oil into new products, businesses and communities can save money and reduce their carbon footprint at the same time.

Simplified process of acylating waste cooking oil, courtesy of Wu and team

The idea to turn used cooking oil into resin for 3-D printers was inspired by a similar experiment conducted using soybean oil.  Both processes follow a one-step chemical reaction called acrylation. First, the oil is filtered to remove impurities, and heated at 80०C while spinning.  After four hours, the oil mixture was then cooled and mixed for 18 additional hours before a variety of chemicals were added to wash the material. Vacuum the mixture to extract the oil and voila!  High-grade, biodegradable, contaminant-free, and 3-D printable resin.

DIY 3D Printer, courtesy of Creative Commons

Basic structure of a 3-D printer, courtesy of Creative Commons

While the cooking oil resin produced is not as high of quality as the best commercially available 3-D resin, MiiCraft, it can still hold its own.  First of all, it’s significantly cheaper than MiiCraft which that goes for ~$500 a liter because cooking oil resin uses commonly supplied chemicals in the treatment and is made from recycled material.  As mentioned earlier, cooking oil resin is also biodegradable, meaning it is much better for our planet in the long run.  In fact, the only downside to this method of resin production in comparison to MiiCraft’s is that MiiCraft yields a slightly better resolution when printed.

In the future, the cooking oil research team is looking to make the acrylation process even greener.  They urge their peers to investigate alternatives to the chemicals used in synthesis to reduce waste while maintaining a high percentage of resin product.  The team also encourages fellow scientists to reach out to other prolific restaurants and perform similar experiments on different cooking oils.

https://pubs.acs.org/doi/full/10.1021/acssuschemeng.9b06281

Wu B., Sufi A., Biswas R. G., et. al. Direct Conversion of McDonald’s Waste Cooking Oil into a Biodegradable High-Resolution 3D-Printing Resin. ACS Sustainable Chemistry & Engineering 2020 8 (2), 1171-1177. DOI: 10.1021/acssuschemeng.9b06281