Quick-change MRF

Santa Barbara County’s Resource Center in California quite possibly could be a model of efficiency for future material recovery facilities (MRFs) in North America. Conceptualized roughly 20 years ago, the mixed waste processing facility at the Tajiguas Landfill site has been in operation since 2020 and is designed to meet the state’s stringent organics recycling diversion targets set for 2025. Plus, it recovers valuable recyclables from municipal solid waste (MSW) that, just a few years ago, would have been landfilled.

“What makes the facility unique is it must sort all materials before disposing in the landfill,” says Wilfred Poiesz, recycling system design and sales manager for Van Dyk Recycling Solutions, based in Norwalk, Connecticut—the MRF builder. “It runs both MSW and single stream on the same circuit.”

Beyond this, Carlyle Johnston, project leader at the County of Santa Barbara, adds, “We have the landfill, MRF, organic anaerobic digestion facility, mulcher and compost at this site. We are the only facility to have all these operations sited at one location.”

A green solution for organics

California’s SB 1383—dubbed the biggest change in waste management in more than 30 years—targets organic waste to reduce short-lived climate pollutants. It requires the state to reduce 75 percent of organic waste, including food, green waste and paper products, among others, by 2025. In 2018, California disposed of approximately 24 million tons of organic waste, and the mandate targets reducing this by more than 20 million tons by 2025.

The facility’s design was, in part, geared toward meeting those mandates. The Tajiguas Landfill provides commercial and residential waste services to the South Coast and the Santa Ynez and New Cuyama valleys. “We serve approximately 220,000 people,” Johnston says. “Santa Barbara is an affluent county, and the general rule is waste generation increases with affluence. Waste generation for county residents averages 9 pounds per person.”

The facility first shreds MSW to break apart and resize materials before being processed. “The automated circuit handles material between 2.5 and 14 inches,” Poiesz says. After shredding, a series of trommels and screens sizes the material, and any heavy material falling through the 2.5-inch screens is treated as organics and sent to the anaerobic digesters. It is converted into compost and biogas for electricity.

Johnston explains the importance of removing organics from landfilled materials. “Decomposing organics emits methane gas, which is a short-lived climate super pollutant 25 to 100 times more potent as a GHG [greenhouse gas] than carbon dioxide (CO2),” he says. “In addition to biogas, the site also employs solar and landfill gas for our power needs to make us self-sustaining plus a donor to the grid.

“This facility is the single-largest reducer of GHG in the county. We are reducing 117,000 metric tons of CO2 annually, which is equivalent to taking 28,000 cars off California’s roads.”

Commodity recovery profits

With 20,000 square feet of tipping floor space, Alan Coulter, general manager for MarBorg Recovery, the operator of the resource center’s MRF, says space is tight. “We can’t keep material sitting on the floor for too long. We must keep it flowing from the floor to the circuit,” he says.

The automated sorting circuit’s designed capacity is 1,000 tons per day.

“We currently run, on average, 800 tons per day of both MSW and single stream,” MarBorg Operations Manager Brandan Fix says.

The screening process also separates oversized material greater than 14 inches, diverted from the automated circuit for manual sorting. “Our goal is for quantity of material removed from the stream, so we employ manual sorters to help maximize material recovery,” Coulter says.

“We have a 60 percent contracted diversion rate from the landfill for MSW material,” Johnston adds.

The remaining 2.5-to-14-inch material is sent through a series of 10 Tomra Autosort units for recovery of valuable recyclables, including rigid plastics, plastic film, paper and wood. Ty Rhoad, regional director Americas for Tomra Recycling Sorting of Charlotte, North Carolina, says, “MSW contains valuable secondary raw materials. If they are recovered through mixed waste sorting and further recycling, we take circularity and greenhouse gas benefits to new heights.”

Johnston mentions the landfill is benefiting from the circuit’s designed flexibility. “Van Dyk was hired because they have better equipment, and I believe the Tomra units are better sorters,” he says.

As a preferred supplier for Tomra sorting technology in North America, Van Dyk has extensive experience incorporating flexibility into its system designs. The facility’s designer and installer focuses on “future-proofing” MRFs, helping them to adapt to market changes today and many years down the line. The facility was designed to be able to capture any commodity to keep up with the evolving tonnage.

“We are now recovering a PP No. 5 product for sale, and that market didn’t exist when the facility was in development,” Johnston adds.

Compact and highly flexible, the Tomra Autosort multifunctional sorting system can be used across a range of material sorting applications, including MSW, single stream, plastics and e-scrap. The new generation Autosort incorporates the latest Tomra technologies to offer advanced accuracy of complex sorting tasks, such as pulling recyclables from MSW feed material at high throughput rates.

Using near-infrared (NIR) and visible light spectroscopy (VIS) to identify objects, Autosort’s Sharp Eye technology increases light efficiency while maintaining the same energy consumption to advance sorting sharpness and improve separation of difficult-to-target fractions.

The sorters also include Tomra’s patented Flying Beam sensing technology to offer better light efficiency, flexible and easy installation and enhanced light signal efficiency for improved detection. Combined, the Sharp Eye and Flying Beam technology help consistently deliver high-performance sorting accuracy across all target fractions, with Coulter adding, “Automation and the Tomra sorters are the most consistent part of the operation.”

Van Dyk designed the resource center’s circuit to use a positive sort, where the desired recyclable material fractions are ejected by the valve blocks, to increase recovered material purity. Each Autosort unit is equipped with three to four different “recipes” of materials that operators can select to recover from the unit.

“Autosort can be configured with dozens of recipes for recovered materials. Tomra collaborated with Van Dyk to configure the sorters according to the customer’s needs, and then Van Dyk installed the units, programming them with the required recipes,” says Parker Bynum, western area sales manager for Tomra Recycling Sorting.

“We are impressed with the flexibility of programming to quickly change recipes to fire on different material,” Fix adds.

Quick switch to single-stream 

MarBorg runs MSW through the automated sorting circuit throughout the day, and it sorts single-stream recyclables during the second shift. The circuit only shuts down for approximately 30 to 45 minutes to allow workers time to clean the screens and change Autosort’s recipes to single-stream sorting. “It takes less than five minutes with a couple of workers to change the sorting configuration on each machine,” Fix says.

When running single stream, workers increase feed material conveyor belt speed through the circuit. Currently, the facility sorts and recovers five different specification recyclable plastic products, cardboard, aluminum and paper. “I like that we can shoot on both wood and plastics using the same technology,” Coulter says.

The recovered recyclables help to defray the resource center’s annual operating costs. “The recovered products generate approximately $6 million in sales annually. Although the facility is not self-sustaining, it lowers the facility’s operating costs,” Johnston says.

More importantly, the resource center is achieving its goal of diverting material from the landfill. This extends the life of the Tajiguas landfill and puts off the need to expand or site another landfill. “Between sorting MSW and single stream, our goal is achieving a diversion rate of approximately 80 percent,” Coulter says.

To comply with a portion of California SB 1383, the innovative resource center has created an Education Center, where it opens the facility to groups of people ranging from school-age students to senior citizens. Each year, more than 1,000 visitors tour the Education Center to learn more about waste and recycling.

“We have turned this facility into a real community resource,” Johnston says. “Trash is a great launching point for talking about the environment. We want people to see how we live our lives impacts waste generation and how the facility reduces that waste through recycling. It’s a discussion we all need to have.”

This article was submitted on behalf of Tomra Recycling Sorting, Charlotte, North Carolina. More information is available at https://solutions.tomra.com.