Garbage In, Energy Out

Crunching on that crispy eggplant pakora from our lunch buffet, do you ever wonder what happens to all the extra oil once it leaves the fryer? For many restaurants, the question seems short on easy answers. Spent cooking oil can create a host of problems, clogging pipes, increasing the volume of trash, damaging sewers, and harming wildlife.

Fryer Oil Problems
Aside from the tasty output, a deep fryer can wreak havoc on both life and property. (Illustration by Patricia Lamas)

Part of our work here at Gandhi Mahal is turning our waste streams into energy cycles. In other words, we put that grease back in action! Walk through the service alley behind Gandhi Mahal, and you might see a collection of bright blue barrels huddled by the dumpster. These are recycling bins for used cooking oil, and are regularly serviced by Sanimax, a company that collects various industrial waste materials and converts them back into useable products. One of their largest operations is producing biodiesel from used cooking oil. By keeping our extra grease out of the landfill and instead sending it through a process of purification and chemical conversion, we are taking steps to close the loop on another waste stream and provide a new source for renewable energy.

Fryer Oil Solutions
After frying some delicious samosas, our cooking oil is deposited in a collection barrel then converted into biodiesel. (Illustration by Patricia Lamas)


What is Biodiesel, Anyway?

Similar in combustion properties to traditional “petrodiesel” but derived instead from plant material, biodiesel is a renewable energy source and tends to be much cleaner-burning than its dinosaur-based counterpart. It can be made from any number of plant oils, including the stuff you put in your boxed brownie mix. Hold on, though, don’t just go running for the pantry next time your tank is low! Biodiesel is made using a process called esterification, which means reacting such fats with alcohols to produce fatty acid esters. The end product is ready to use in any modern diesel engine — no special equipment necessary. While the potential environmental costs of producing biofuels on an industrial scale are of due concern (potentially demanding evermore large-scale mono-crops and in turn taxing the global food supply), reusing what’s already on hand (the grease vat swimming with veggie samosa crumbs) is a no-brainer, at least for the time being.


A New Spin on an Old Practice

Though biodiesel itself has become quite popular in recent years, the idea of recycling industrial waste oils is nothing new! Sanimax was in fact founded in 1939 by two Quebecois brothers, a butcher and a slaughterhouse administrator, who sought to put their knowledge of meat processing to use in a new business venture. The company, then named Couture, Ent., collected various meat byproducts from local businesses and converted them into value-added products, an old process called rendering. Their first outputs included mostly tallow, used for soap making, and bonemeal, a livestock feed supplement that was still barely gaining a foothold in the consumer market (even if your idea for an “upcycled” product has yet to resonate, like bonemeal it may just need time and some good old-fashioned pedaling!). Especially in those days, rendering was a grimy, grueling undertaking. Even into the 1950s, employees hand-loaded barrels of meat scraps and wheeled them back to the plant on horse-drawn carriages. It was this hustle on the part of the business that made the service so attractive to its clients. Finally, a way to offload all that stinking carnage without getting their hands quite so dirty!

Over the years, both technology and consumer demand paved the way for both new rendering processes and sellable products. And with the occurrence of Bovine Spongiform Encephalopathy (“Mad Cow Disease”) in the 1980s and resulting safety restrictions, the need for innovation suddenly kicked into an even higher gear. Distribution largely halted and warehouses full of bonemeal were left unsellable. During this time of economic disruption, Sanimax heightened its efforts to seek viable alternatives, closely watching the renewable energy scene in Europe. As the demand for biofuels grew and as businesses in the U.S. showed more interest in lightening their environmental impact, the recycling of used cooking oil quickly moved into the forefront of Sanimax’s work. (Source:


What’s Next?

What do you throw out at home or at work? Opportunity abounds. Today, a growing number of entrepreneurial minds are seeking new ways to put waste back to good use. In order to catch on with the larger public, though, the next challenge is to make the new alternative just as easy as taking out the trash. Sanimax has made it ridiculously convenient for restaurants to dispose of their spent oil without the mess. How else can we reinvent our waste streams so that the most conscientious solutions are also the most obvious?