Processing Pressures: Retain Quality, Increase Quantity

Lynn Merrill

Whether you're a small recyclables processor or a large one, the secret to future success is "more" - more materials processed per shift, more capacity per piece of equipment and more pressure on lowering costs.

This is not surprising, since most processing facilities operate on a cost-per-ton basis to amortize capital and operating costs.

The growing recyclable tonnages collected from both the residential and commercial sectors are stymieing processing facility operators: As material volume increases, end users continually are tightening their acceptance standards in markets best described as volatile.

In the middle are processors who must move more tonnage through their facility while generating a higher quality product than ever. This is not impossible. The following examples illustrate the developing innovations.

Chicago's Hope: Blue Bags During the past 10 years, recyclables collection technology has come full-cycle. Before the first recycling route was even conceived, everything - recyclables and waste - was loaded into a single truck and hauled to a central transfer station, waste-to-energy (WTE) facility or landfill.

The industry since has grown and matured - from the initial curbside collection efforts using multiple stacked bins and curbside sorting to automated collection of recyclables which are separated in processing facilities. The advent of the Chicago blue bag collection system completes this circle.

Since December 1995, Chicago residents have been separating and bagging their waste into three streams: yard waste placed in kraft bags; glass, metal and HDPE and PET plastic containers; and paper.

Both the containers and the papers are placed in separate translucent blue bags, which are then placed in the receptacle and collected with one truck.

Waste Management Inc., Oak Brook, Ill., operates four blue bag processing facilities in Chicago (see chart on page 18), each capable of handling between 1,000 tons per day (tpd) to 1,600 tpd for a total capacity of 6,400 tpd. On holiday weeks, this system can handle a maximum of 7,500 tpd.

The collection vehicles dump the material on the tipping floor where it is pushed by a front end loader to a grapple which feeds two end pits. Then, the mixed material is elevated by conveyor to the sorting stations.

As the material is transported on the sorting belt, it is inspected for items that could damage the equipment. At this stage, yard waste bags are removed.

Blue bags containing glass, aluminum, HDPE and PET plastic and ferrous containers are transferred to one sorting line, while bags with paper (such as newsprint, corrugated cardboard and junk mail) are sent to a second sorting line.

"What's left on this belt is mixed solid waste - things that people have not taken any time to segregate," said Lockman. This waste is filtered through a trommel with gradiated openings.

These holes range from two inches (to remove fines, grit and dirt) to nine inches (to remove containers which are directed to the container processing line.) Materials longer than nine inches are sorted a second time. Anything remaining is loaded by grapple onto a live floor trailer and transported to the landfill.

After the containers are opened, the materials travel to a quality control station for contamination removal. Broken glass is screened prior to the material's passage through an air knife which separates the glass from the plastics. A belt magnet removes any ferrous material.

The plastics and aluminum that are blown over to one side continue along a sorting line where they are separated into the various plastic grades and aluminum. Glass that is too heavy to be pushed by the air knife is lifted onto a vibrating conveyor which separates it by color.

The blue bags filled with paper are processed similarly. Mi-chael Lockman, Chi-cago Sorting Centers' division president said, "Our stream is clean enough to do a negative sort for number six news, but we recover two-thirds of our material as number eight news."

All sorted materials are placed onto bunk-ers with live floors which transport them to a conveyor that connects to one of two balers at each site.

Approximately 10 percent of the waste stream is recovered - 8 percent mixed waste and 2 percent through the blue bag program. "We're above 10 percent now that we've started to see yard waste kick in," said Lockman.

While contamination continues to be a concern, effective quality control strategies ensure a high-standard product. "We've been accepted at every mill we've gone to," Lock-man said, although it took longer than a month to get "the bugs worked out." However, they were able to make first grade of every material, including getting a number eight out of the newsprint's dirty side, he said.

Catching California's Markets Orange County's Taormina Indus-tries boasts the largest, privately-owned material recovery facility (MRF) in southern California, with an 8,000 tpd capacity, and a daily average throughput of 4,000 tpd.

Located in Anaheim, the facility processes materials from 33 cities collected by both Taormina's exclusive hauling franchises and other haulers.

The company's success at processing materials coupled with its ability to secure major end-market users has increased its need for more recyclable materials, driving future expansion plans to include building a new processing facility capable of handling 1,800 tpd to 6,000 tpd. This facility will be housed in a former government defense contractor building in Pomona, Calif.

Taormina also is tapping San Bernardino and Riverside counties' need for processing capacity. Re-cently, Taormina was awarded a franchise to collect Colton's solid waste and recyclables, and in late May, it opened a light material consolidation facility in San Bernardino, thus allowing the company to transfer co-mingled recyclables to Ana-heim.

Taormina currently processes and markets more than 70 different commodities from this facility. Its system blends conveying and gravity feed systems with finger screen and manual separation, magnetic separation and high-grading of individual products, said Taormina chairman Dave Ault.

The Anaheim facility is capable of processing both clean and dirty feed streams on two separate lines. Loads of co-mingled recyclables are dum-ped in one area, while mixed refuse is dumped in another. The target materials are separated manually through a variety of conveying systems.

More than 125 employees work each shift in as many as five different separation operations. For example, the glass and aluminum small classification line operates with 12 people.

The New England Niche Today's recyclables processor is more likely to secure long-term commitments with high-volume quality materials.

While this can be a problem for smaller communities, the Northeast Resource Recovery Association (NRRA), Concord, N.H., is helping small towns and villages discover markets for their lower volumes.

While the NRRA is not a direct processor, its cooperative marketing program serves 175 municipalities in Maine, Vermont and New Hampshire. Strin-gent processing re-quirements and an effective transportation network ensures a place in the market for these small collectors.

To maximize the market for fewer recyclables, these municipalities jointly issue a Request for Proposal for bids on their materials.

The cooperative has seven contracts for approximately 22 commodities, including all fiber grades; plastic grades one to seven; green, brown and clear glass; textiles; aluminum and tin cans; and scrap iron.

"We move about 25,000 tons of material per year through our cooperative marketing program," said Dana Draper, the NRRA's executive director, who notes that this is a "significant volume" for New England.

Quality control is a high priority. Draper said that tight materials specifications impacts processing but also guarantees quality materials, ensuring market durability for the small collectors. "[Buyers] tend to call us first if there's an inventory need, and they know they can go right from the truck to the manufacturing process without having to worry about contamination," he said.

Running the cooperative marketing approach involves coordinating the operations of many small, geographically-diverse processors over a tri-state region. Because each processor must produce the same quality, prospective candidates must be part of the NRRA's marketing programs, and either attend a workshop or meet with the technical assistance manager who will explain the program.

Communities also must comply strictly with specifications for each commodity. This has resulted in a "less-than-one-half percent rejection rate at any given time," said Draper, who has received only one rejection call in his eighteen months of service.

To maximize transportation efficiency, the NRRA also coordinates pick-ups from each member. "If communities aren't able to aggregate truckload storage, they call us a week before they're desperate to move five to 10 bales of plastic," Draper said.

The NRRA does not own equipment, so it contracts with truckers to retrieve these loads. The truck is weighed after each stop and delivers to the buyer's facility that day.

Pushing It Through While some companies stress automation to reduce hand sorting costs, others believe it cannot accomplish the high quality requirements necessary to ensure markets.

Each facility must be designed with the feed stock in mind. The materials processed are abrasive and can result in increased downtime and excessive equipment wear, both of which reduce cost effectiveness.

Nathaniel Egosi, President of RRT Design and Construction, Melville, N.Y., stressed seeking "first tier" manufacturers to supply facility equipment. He suggested patronizing manufacturers that have been around for a long time and have a solid reputation.

In designing a processing facility, Egosi looks for equipment that is medium- to heavy-duty and in OSHA compliance. "OSHA provides guidance and minimum requirements. 'Minimum' is subject to interpretation, so [manufacturers] can get away with less," Egosi said.

The tons processed per hour should justify the equipment cost, said Taormina's Ault, who added that the type of processing will be a variable.

Processing equipment manufacturers are taking heed according to Richard Harris of American Baler, Bellevue, Ohio. The trend toward larger and faster baling equipment and the need for a larger feed opening grows as MRFs strive to streamline their workforce and increase efficiency.

As the market price for various commodities continues to fluctuate, maintaining quality and low costs are key.

"You have to have product quality coupled with the ability to give enough product quantity to an end user," said Taormina's Ault. "Put those two things together, and there's no secret involved."