You may be flushing a valuable resource down the metaphorical drain when disposing of grease trap waste. Yes, the big bad wolf of commercial plumbing that the industry has struggled to combat over the past two decades may be hiding a gem in that mess of congealed fats, oils and grease.
New technologies are allowing the possibility of resource recycling for FOG, and it’s arriving at a time when FOG is considered one of the most significant problems facing municipal systems and treatment plants.
“There’s just a massive amount of FOG out there, and the challenge has always been how do you effectively manage this stuff and keep it out of the infrastructure,” says Brian Levine, executive vice president for Greasezilla, which provides a self-sustaining, micro-footprint brown grease recycler.
While the idea isn’t exactly new, it is more accessible — and more lucrative — than ever before. Accessible systems and wider acceptance in the energy sector have made brown grease recycling a viable solution for treatment plants across the country.
The idea is simple; haulers already have to dispose of the waste they are pumping out of grease traps, one way or another. Instead of dewatering and landfilling — which requires high tipping fees and inefficient disposal — treatment facilities could install a recycling system and actually profit off FOG.
It’s a win-win, because low operating costs and the possibility of market sales means lower tipping fees. So pumpers pay less and make more money — potentially even lowering the customers’ costs — while municipalities make money on the back end.
“Any one of our sites can bring the price down for the haulers so that the site is doing well, and the hauler’s making some money. And when the hauler makes money, there’s no impetus to look for shortcuts, and that’s super important,” Levine says.
Brown grease recycling systems are relatively simple technology. Basically, you’re putting the grease trap waste into a silo, reactor, or some other decanting container that is heated slowly over a half-day or more. The reusable brown grease rises to the top, and what’s left is simple wastewater, ready to move on through the treatment plant without issue.
Getting FOG out of the waste stream has been an issue for some time, costing municipalities across the country billions of dollars per year. Traditionally, the only realistic options were to compost, incinerate or land-apply the dewatered FOG — none of which are environmentally friendly or economical.
“These other solutions have waned. Land-applying — with whatever was in the dishwasher, whatever was on the plate, whatever soap was used in the dishwashing process — that’s no good. Composting, that takes way too long. Dewatering, that creates a sludge that still has to be processed,” Levine says. “We have no waste at the end of the recycling process. There’s nothing to discard, nothing to bury, nothing to landfill, nothing to pass on.”
Another benefit of grease recycling is that it removes FOG from the waste stream on the front end.
“The key to this is getting grease out of the substrate, out of the waste stream, immediately. The second it comes into the facility, we decant it, which just allows natural gravity separation, and then put it through our reactors to get the water and grease separated immediately,” Levine says. “I don’t care if you want to run it through dewatering systems or dissolved oxygen floatation systems, whatever you want to do, the sooner you get the grease out, the easier and less-expensive the whole process becomes for you.”
Greasezilla claims to have a cost of operation less than 2 cents per gallon, which is a pretty compelling stat considering most pumpers and haulers today pay 10 to 20 cents on the gallon in tipping costs.
“The hauler has to go a long distance, then they have to find someone who will take it quickly, and then they have to find a place that will leave them a little bit of margin for themselves,” Levine says. “This has always been the problem: there are not enough places to receive it, and some are very selective on who they’ll even take it from. It’s very expensive to drop it off.”
Not only is there a demand in the treatment industry for cheaper processing options, there’s also a growing market for the saleable biofuel end product.
“Brown grease is a commodity. Brown grease trades on commodity boards, so you can sell that within a day, and it could end up in a myriad of industries, or around the world. Europe has big subsidies for using brown grease,” Levine says. “It has become a very inexpensive substrate in the biodiesel industries, so there’s never been a more robust market for brown grease, because there have never been more uses for it.”
There has been a lot of movement in the industry over the past decade to begin using brown grease as a base for biodiesel products, on top of its use long-standing use as a popular marine shipping fuel. Because it is a clean-burning biofuel relative to petroleum-based diesels, it can be used on ships in coastal waters where environmental regulations hold sway.
“You’ve created a beautiful organic biofuel — it burns incredibly clean, it’s organic and natural, it’s way cleaner than natural gas, and it’s sold all over the world,” Levine says. “There’s been a lot of pressure on the biodiesel world to find a less-expensive feedstock.
“We hear this a lot, ‘the only reason we take FOG is because we have to, not because we want to.’ Another great quote from one of our customers is, ‘we handle some pretty nasty stuff in wastewater treatment facilities; nothing gives us as much of a headache as FOG.’ Because grease doesn’t like to break down very easily. If you push it through, it really clings to the slurry, affects the equipment, and at the end of the day, it survives the whole process — you still have grease to deal with,” Levine says. “The best possible thing to do with this substance, this waste stream, is to break it back down to its basic elements: water and oil. If we can do that, they we’ve created an organic product. The water will go right back to the city, and the organic substance can be sold and have another life.”