Until late April, not many residents of Berkeley County, S.C., recycled, as they either had to hire and pay a private hauler or drive materials to a drop-off center. Now they have another option, and all they have to do is toss salvageable materials in with their trash, which will be sorted and made into commodities for plastics, paper and metal manufacturers, or made into an engineered fuel to power industrial plants.
The Berkeley facility, which is owned and operated by RePower South, became fully operational in late April and can process 200,000 tons a year leveraging both mechanical processes and automated “smart” technologies.
The company launched a similar facility earlier in 2019 in Montgomery, Ala., that can manage about 170,000 tons a year.
At the front end, old corrugated cardboard, polyethylene terephthalate (PET), high-density polyethylene (HDPE), aluminum and steel will be processed and baled, says Brian Gilhuly, CEO of RePower South.
Engineered fuel will be made from much of what’s left, in the form of size-reduced shred.
“Shred is specifically designed for fuel delivery systems at cement or industrial facilities (our customers). And it’s cheaper to produce than pelletized fuel, so we can pass on production savings,” says Gilhuly.
There also are regulatory advantages, as engineered fuel is considered a non-waste fuel, which falls under the U.S. Environmental Protection Agency’s normal fossil fuel rules.
“Customers can fire this low-carbon, renewable fuel without changing their traditional fossil fuel air permits because it’s cleaner than coal,” says Gilhuly.
The Berkeley materials recovery facility (MRF) employs screens and pneumatic air separation for lights and heavies. Magnets remove metals. Infrared optical sorters manage PET and HDPE as well as act as a final filter to remove unwanted contaminants, such as remaining metals and chlorides.
Newer technology called Max-AI automates the quality control process, leveraging a computer to identify materials based on images and a robotic arm to pull objects from the conveyor or allow them to pass.
“Additionally, this system provides a data set of exactly what material is being presented. So now, for example, if I get a lot of aluminum cans on my PET belt, I have data showing this and to help determine why. I can go back to the recovery process and adjust to pull aluminum earlier,” says Gilhuly.
At Berkeley, about 10 to 15 positions will be handled by machines, which Gilhuly says are lower paid, difficult jobs with high turnover. There will be about 50 employees, including four human pickers per shift with the remaining staff handling receipt of material, managing inventory and shipping and maintaining equipment.
Bulk Handling Systems (BHS) provided all the equipment for the Berkeley and Montgomery facilities. The fuel system was provided by Loesche.
“We have successfully deployed the front-end, patented processing system in mixed waste and mixed recyclables settings. The key part of the process involves separating high-value commodities from the organic and inert part of the waste stream, and then a series of refinements using screening, air, optical and robotic technology,” says Steve Miller, CEO of Bulk Handling Systems.
The non-recyclable paper and plastics fed into the Loesche Rocket Mill are reduced, and much of the moisture is eliminated, raising the calorific value. The end product—engineered fuel—is considered a more refined refuse-derived fuel in that it is highly processed with minimal-to-no inerts, metals and polyvinyl chloride.
Each engineered fuel customer has unique needs, and setting up for them entailed an understanding of the material handling and boiler configuration in each scenario, explains Daniel Hughes, interim managing director of Loesche Energy Systems.
The Loesche Rocket Mill has several attributes that are unique in comparison to traditional shredders, he says. Among them, screens can easily be changed to control size reduction of the fuel. Material is smashed rather than cut to produce a fluffier material that burns better. And the Rocket Mill rejects metals and other heavy contaminants, ensuring a cleaner product.
Storelli Recycling will market commodities from traditional recyclable materials.
“[With increasing and changing market demands], the addition of robots and optical sorters has given us an opportunity to evaluate all materials and understand what’s in the stream. This includes outhrows, which allow us to better inspect what comes in to see what other commodities we can salvage,” says Victor Storelli, chief financial officer of Storelli.
For now, about 40 percent of the incoming stream will be landfilled, about 20 to 25 percent will be recovered as traditional blue bin materials and about 35 percent will be salvageable as fuel.
“While there will still be residue that goes to landfill, we will continuously look at the balance of the stream to figure out how to divert more material,” says Gilhuly.