An engineered solution

NuCycle Energy manufactures Enviro-Fuelcubes, an engineered alternative fuel that is designed to be a cost-effective and cleaner replacement for coal and other traditional fossil fuels. The company opened its manufacturing facility in Plant City, Florida, in 2019. The 103,000-square-foot plant has the capacity to divert more than 200,000 tons of commercially generated waste from landfill annually.

To produce its Enviro-Fuelcubes, NuCycle employs a variety of size-reduction recycling equipment to process the incoming material as well as cubers, or densifiers, that the company engineered in-house and built in partnership with a trusted fabrication shop.

Double the benefit

Mark Barasch, CEO of NuCycle Energy, says his company addresses two societal problems: the use and proliferation of landfills and the use of coal in energy-intensive industrial processes. Its Enviro-Fuelcubes, which are made using nonhazardous industrial and commercial materials that otherwise would be considered waste, can be used in suspension burning combustion boilers, such as those used in lime and cement manufacturing and power generation.

“It’s only waste if you waste it,” he says of the material the company uses to produce its product. “If you take it to the landfill, it’s waste. If you take it to me, it’s source material to make alternative fuel.”

NuCycle is taking mixed paper, cardboard, wood/biomass and plastic that its commercial generators supply and combining it in such a way that it can produce a product with at least 85 percent biomass content that has a consistent Btu value of 9,500 to 10,500 per pound that allows Enviro-Fuelcubes to replace coal pound for pound. Barasch says most biomass and alternative fuels don’t have the inherent Btu value that is needed for lime and cement production.

Additionally, burning Enviro-Fuelcubes results in 1/60 the mercury, 1/60 the sulfur, 1/113 the lead and 1/174 the arsenic of coal, he says. “We are a much greener fuel than coal,” Barasch says. “It’s not just about the carbon.”

“Regarding our process, we are fortunate because the source material is very clean,” says NuCycle Director of Engineering and Technology Brandon Hagerman. “We control what we bring in with our sourcing model, so every material gets qualified for both chemical characteristics and physical characteristics for the process.”

This incoming material is blended before being loaded via pit conveyor into the first of two shredders to begin the production of Enviro-Fuelcubes.

Bringing things down to size

The primary reducer, a Pri-Max PR4400 manufactured by SSI, Wilsonville, Oregon, combines ripping and shearing technologies “to shred, tear, pierce, chop, split, flatten, crush, break and reduce materials,” according to the manufacturer. The cutter profiles and open cutting table design help to achieve high-capacity reduction. The primary reducer produces a nominal 6- to 12-inch particle size.

Vecoplan LLC, Archdale, North Carolina, recently installed upgrades at the NuCycle plant to increase uptime and throughput and to reduce the presence of metals that could damage the secondary shredder and cubers. This involved installing new conveyors and metal removal equipment between the SSI preshredder and Vecoplan reshredder and from the Vecoplan reshredder to the cubers.

Hagerman says, “With the new configuration, we discharge out of the SSI Primax to a robust belt-over-chain conveyor, and that conveyor discharges onto a sort line that provides the opportunity to remove nonconforming/nonferrous materials prior to the metal separation process.”

The sort line discharges onto another transfer conveyor that features a 4-by-8 foot over-belt electromagnet manufactured by Steinert, a German company with U.S. offices in Walton, Kentucky. Hagerman says the magnet captures 70 percent to 90 percent of the ferrous metals in the material stream.

“Just downstream of that, the Vecoplan transfer conveyor has a magnetic head pulley,” he says, which allows the company to capture ferrous material that is closer to the belt’s surface before the material is fed to a single-shaft Vecoplan VEZ 2500TT, which further reduces the material to a uniform 4-inch minus size.

Following the VEZ 2500TT shredder, the material goes to another magnetic removal process that uses a second Steinert electromagnet and another magnetic head pulley, Hagerman says. “We’re seeing much greater than 90 percent efficiency of the magnets that are upstream,” he says. “The downstream magnets are capturing smaller ferrous metals, such as staples and banding. We are seeing great metal removal efficiency.”

Hagerman says NuCycle has targeted 30-ton-per-hour flow rate with its system and has already seen a significant increase in throughput.

Auxiliary processes

A third shredder, a Vecoplan VAZ 1300 XL, is used to process wood and rigid plastics, including purge, in an auxiliary process, Hagerman says. “It’s an important part of the process.”

He continues, “The configuration that we ended up with is due to the variety of materials that we handle. The characteristics are so different that there’s no one answer to it.”

NuCycle also receives a significant amount of roll stock, which it currently must preprocess with a guillotine shear. While films and heavy roll stock are not considered unshreddable, Hagerman says they would be difficult for the Pri-Max to handle if not preprocessed.

He says NuCycle is open to exploring direct grinding or shredding equipment to process that roll stock without the help of the guillotine shear.

Putting it all together

Following the size reduction steps, the material is delivered to NuCycle’s cubers, which use proprietary technology. They were engineered in-house and built in partnership with a trusted fabrication shop. Hagerman says, “In general, it’s a rotary press … almost like a pellet mill but not quite.”

He adds, “Ultimately, it takes a 4-inch minus material and extrudes it to an inch-and-a-half or inch-and-a-quarter die opening channel.” The company’s current off-take customer’s application requires no postprocessing of Enviro-Fuelcubes to be ready for use.

NuCycle’s system is designed to operate with three 10-ton-per-hour cubers.

Consistency is key

Achieving a consistent bulk density for the Enviro-Fuelcubes is as important as achieving a consistent heat value. The final particle size of its raw materials plays a critical role in that.

“When we design this plant, we started from the back end,” Hagerman says. “We are a manufacturer that makes a product, so we started with that, and we designed the plant with our finished fuel characteristics in mind.

“In order to achieve that bulk density, we had to have certain parameters, and finished shred size was one of them,” he says. “The other benefit is more efficient material handling in general. When you handle a lot of rolled labels and films and things like that, this approach is needed to make commercially significant quantities of fuel.”

Depending on a fuel buyer’s needs, the company’s cubers can be fitted with different tapered dies to achieve different densities, he adds. “If we wanted to increase density, we can do so without changing infeed material size. There’s a lot of flexibility in what our end product can be.”

The author is editor of Recycling Today, a sister publication to Waste Today, and can be reached at dtoto@gie.net.