An eye on the future

Features - RDF

In an effort to pursue the company’s zero waste ambitions, Geocycle LLC uses an Untha XR mobli-e waste shredder to produce refuse-derived fuel.

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September 9, 2020

Photos courtesy of Untha

Since the 1970s, Dundee, Michigan-based Geocycle LLC, a part of the global Geocycle network, has developed tailored industrial and municipal waste management services for its customers. With Switzerland-based building material producer LafargeHolcim under the Geocycle brand, the company says it is uniquely positioned to offer sustainable solutions for managing waste.

Partnering with industries, service companies and municipalities to help them achieve their environmental commitments, Geocycle employs the methods of “preprocessing” and “co-processing” to offer its customers an environmentally friendly solution for handling waste.

According to Nicolae Cuzuioc, director of processing expertise and business development for Geocycle North America, employing these methodologies enables the company to recover energy and recycle materials from different sources of waste.

“Co-processing is the use of waste as a raw material, or as a source of energy, to replace natural mineral resources and fossil fuels, such as coal, petroleum and gas in the cement manufacturing process,” he says. Currently, Geocycle converts more than 2 million tons of waste per year into alternative fuels and alternative raw material (ARM).

Before this waste byproduct can be used directly for co-processing into Geocycle’s cement kilns, it must undergo a preparation process called preprocessing. The company says this step delivers a stable product that complies with the technical specifications of cement production and guarantees that environmental standards are met.

"Co-processing is the use of waste as a raw material, or as a source of energy, to replace natural mineral resources and fossil fuels, such as coal, petroleum and gas in the cement manufacturing process,” –Nicolae Cuzuioc, director of processing expertise and business development for Geocycle North America

“The goal is to use more than 5 million tons of waste per year in our LafargeHolcim North America and third-party operations,” says Cuzuioc.

To help further Geocycle’s efforts to achieve a zero waste future through preprocessing and co-processing, the company invested in a XR mobli-e waste shredder from Untha Shredding Technology, Austria, via a U.S. subsidiary, Untha America Inc., based in Hampton, New Hampshire, in 2019.

The mobile unit features two 177-horsepower motors that process nonhazardous, postindustrial waste for the production of refuse-derived fuel (RDF) that will be used for energy recovery at LafargeHolcim’s Holly Hill, South Carolina, cement plant.

A STEP IN THE RIGHT DIRECTION

Geocycle’s nearby Dorchester, South Carolina, facility was previously operating three shredders, two single-shaft shredders and a dual-shaft machine produced by other manufacturers for the preprocessing of waste. But, as damage from unshreddables began to restrict the performance of this incumbent shredding technology, Geocycle made the switch to the XR shredder to facilitate single-pass RDF production.

“I have long been familiar with this brand of equipment, not least because there are a number of Untha shredders in operation in Geocycle facilities worldwide. However, the technology hasn’t previously been right for my co-processing requirements here in Dorchester,” said Cuzuioc in a 2019 release. “When I heard about the new Untha mobil-e and the machine’s ability to handle a number of complex input materials, I was extremely interested. We took delivery of a demo unit from Untha America in late 2018 so that we could trial the shredding technology using our own waste, and it quickly proved such a crucial part of our plant that we retained ownership of this machine until our own machine arrived.”

The shredder arrived at Geocycle’s Dorchester site in late August of last year.

“The Untha XR series has been designed by waste specialists who have lived and breathed this industry for decades and worked closely with operators to understand the true requirements of modern shredding technology,” says Gary Moore, director of global business development for Untha America. “In other words, the machines have been purposefully engineered to solve real industry challenges—in this instance, the environmentally efficient, profitable production of on-specification alternative fuels such as RDF.”

According to Moore, the XR shredder has been designed with input material flexibility in mind. It features a ram-assist feed that helps to handle tougher materials, and different open- and closed-door hopper options equates to added versatility.

“Within a range, there are varying rotor lengths, speed settings and torque capabilities. For example, the safety clutch and high-torque gearbox means materials that some operators may even consider ‘unshreddable’ can now be processed with the XR,” Moore says.

Geocycle uses the XR shredder to preprocess a mix of solids, sludge and some liquids.

“The Untha shredder is very robust … therefore we are [using] it to size [material] from 25 millimeters up to 100 millimeters, [which is] produced from various streams of commercial, industrial and municipal solid waste,” Cuzuioc says. “We also plan to trial it for construction and demolition (C&D) waste that has a high percentage of biomass to help with reduction of carbon dioxide emissions.”

TRANSFORMING WASTE

Geocycle’s RDF production process begins with the company’s sales team finding waste streams that have the proper chemical and physical characteristics, then prequalifying the samples in its labs and shredding platforms.

“Trial loads are delivered to Geocycle’s industrial preprocessing platform for a shredding trial where we test how suitable the type of waste is for the XR shredder and what the potential operation costs are,” says Cuzuioc.

At the preprocessing platform, the material is shredded, mixed with other waste streams and homogenized to create a consistent quality. Following this, the resulting pile of fuel is sampled and checked, with acceptable fuel delivered to Holly Hill where it is co-processed by being injected into the cement kiln via a dosing system.

The mineral part of the waste-derived alternative fuel and ARM replaces primary mineral materials (such as limestone, clay or iron) and the combustible part provides the energy needed for the clinker production. As a result, 100 percent of the waste input is recycled or recovered without producing any additional residue.

“Co-processing is a so-called ‘two-in-one’ process,” Cuzuioc says. “It offers superior benefits compared with traditional solutions.”

Prior to purchasing the XR shredder, the plant used approximately 30,000 tons per year of nonhazardous solids for the production of alternative fuel. With the company’s new investment, the plant’s throughput capabilities have increased significantly.

“The XR was engineered with this application in mind,” says Moore. “Geocycle processes and treats a range of diverse feedstock material, and they’re extremely innovative, with their eye on the future. We’re supporting their desire for flexibility at the same time as maintaining our commitment to helping them produce a high-quality fuel that respects both the environment and their bottom line.”

SUSTAINABLY FOCUSED

According to Cuzuioc, co-processing (including preprocessing) is a proven sustainable concept that can reduce emissions and demands on natural resources while freeing up landfill space.

“Our approach reduces plant emissions and use of both fossil fuels and virgin raw materials in cement manufacturing, thus preserving natural resources and diverting huge quantities of waste from landfills,” he says. “This preserves natural resources and helps safeguard the environment for future generations.”

Cuzuioc says there are several benefits to co-processing, including reducing CO2 emissions and environmental impacts of extraction, transportation and processing of raw materials; conserving natural resources; and utilizing 100 percent of incoming waste.

He adds, “No waste residue is generated as well, as all ashes are incorporated into the final product.”

Geocycle’s Dorchester site currently processes roughly 120,000 tons per year of waste, including, but not limited to, RDF for co-processing into the Holly Hill plant. The company’s goal is to significantly increase its waste processing capabilities in the coming years to further advance its zero waste ambitions.

The author is the assistant editor of Waste Today and can be reached at hrischar@gie.net.