How Is Used Restaurant Cooking Oil Recycled?

Pouring used cooking oil down a drain is not allowed. It can lead to substantial fines and clog city sewer lines with the solidified grease. Fats, oils, and grease (FOG) will combine with materials that residents flush or put down drains, such as flushable wipes, paper towels, and eggshells and form large clumps known as “fatbergs.”

Fatbergs can do incredible damage. The largest fatberg found within the U.S. was around 100 feet long, 11 feet wide, and six feet tall and located in Detroit. With restaurants using an average of 35 gallons of cooking oil per day, it’s important for every restaurant to prevent oil from going down the drains while washing dishes and cleaning the kitchen at the end of the day.

To counteract this, restaurants collect their cooking oil in recycling containers and have grease traps installed to capture grease. Recycled cooking oil is useful for biofuel, animal feed, cosmetics, and soap. To do this, it first has to be collected. From there, it’s taken to plants that convert it into new materials. Here’s what happens to the recycled oil once it’s collected.

Oil Travels to a Biodiesel Production Center for Processing

The company that picks up your oil collects oil from other restaurants, schools, and commercial kitchens and hauls it in a truck to a biodiesel production center. The oil must be refined first.

As used cooking oil contains scraps of food, flour from a batter, breadcrumbs, and other impurities, it must be filtered to remove these small particles. Water and meat juices can also leak into the oil, and those liquids must also be filtered out.

Used cooking oil also has free fatty acids that break away from molecules when the oil is heated for frying. These fatty acids have to be pre-treated to make them suitable for processing. If this step doesn’t happen, it can lead to engine deposits and create piston rings to stick or raise problems with the injection system. Once all of this is done, a process called transesterification takes place.

Transesterification occurs when recycled oil is mixed with methanol or another short-chain alcohol alone with a catalyst like sodium hydroxide or potassium hydroxide. This converts the oil into a mixture of biodiesel and glycerin.

Glycerin can be removed and used in cosmetics and household cleaners. The finished biodiesel is then taken to terminals where it will end up at fuel terminals to go to gas stations for use in diesel trucks and cars.

The Benefits of Biodiesel

One of the most noted benefits of biodiesel is that it reduces carbon dioxide emissions. The Argonne National Laboratory and California Air Resources Board both found that biodiesel rated B100 can reduce carbon dioxide emissions by almost 75%. Less carbon dioxide emissions mean less damage from greenhouse gas. It’s the right step to helping slow global warming.

Other emissions are reduced. Carbon monoxide exhaust emissions decrease by almost half. Unburned hydrocarbons are reduced by 67%. Particulates, which create the black smoke you see with diesel trucks, also reduce by half. Sulfates are reduced by an amazing 100%.

It’s also less likely to create serious fires. Petroleum diesel has a flashpoint of close to 126ºF. Biodiesel’s flashpoint is much higher at 266ºF. With rising temperatures in some areas, it’s a concern that summer temperatures are nearing the 120º range. The hottest temperature on record is 134ºF and was recorded in Death Valley in 1913, but Washington State recently came close with 120ºF in 2021. A higher flashpoint is safer.

Biodiesel is recycling something that’s already being used. Restaurants need it, but instead of it being a one-and-done product, it gets reused. It eliminates the need for petroleum-based diesel.

You don’t need special additions to your diesel engine in order to use biodiesel. If you have a diesel engine, you’re ready to use biodiesel. The only change you might need to consider is replacing natural rubber fuel lines, if your vehicle has them, as biodiesel can cause the rubber to expand slightly.

It can be mixed with petroleum diesel. If a driver has biodiesel in the tank and cannot find another biodiesel station, it’s okay for drivers to mix these types of diesel.

Have you ever been walking on a city street and had a diesel engine pass you and all you could smell is fried food? That’s another benefit of biodiesel. The days of smelly, black diesel fumes end. Instead, the engines emit a smell that’s just like you get making fries or other fried foods.

Not only is it safer in terms of fire risk, but it’s also safer for the environment. If there’s a spill, it’s not toxic. It won’t harm the environment. In fact, it’s not much different from spilling salt. It’s less toxic to fish and aquatic animals and won’t harm animals and people.

Biodiesel is better for lubrication. Petroleum diesel has had to have sulfur reduced to meet federal regulations, and that reduced the lubricity in petroleum diesel. This led to premature wear of engine components, so additives became necessary to reach the ideal lubrication levels. The higher the cetane number, the more fuel lubricity there is. Biodiesel has higher cetane levels.

Drivers don’t have to worry about poor fuel economy. While it’s slightly lower with biodiesel, it’s only about 5% different. That’s not that much considering the environmental benefits and the fact that used cooking oil is being recycled.

Get a Credit for Recycling Your Cooking Oil

Customers get free cooking oil recycling service as part of their regular grease trap cleanings with NW Biofuel. Our container is sized for your restaurant’s needs and designed to be stored safely outside. If you lack the space to have it outside, an indoor container is provided instead.

A driver comes to your establishment, attaches a drain hose to your container, and suctions the oil from it each week, every other week, or once a month. Don’t worry about the driver interrupting your kitchen. The schedule is designed so that it doesn’t impact your kitchen. When possible, drivers arrive early in the morning before anyone is working. If your container fills faster than expected, let us know and we’ll empty it within 24 hours.

If you aren’t having your grease trap cleaned and inspected regularly, it’s an important step to prevent grease from clogging sewer lines and causing sewage overflows. Make sure you are set up for regular cleanings with NW Biofuel and enjoy free cooking oil recycling and get a credit on your bill. Ask us about our $25 convenience discount when you schedule your grease trap cleaning.