Embracing automation

When fully automated waste and recycling facilities were just a concept in the industry, Norwegian municipal solid waste (MSW) hauling company Romerike Avfallsforedling (RoAF) turned the concept into a reality.

Powered by a sorting system installed by Germany-based Stadler Anlagenbau GmbH, RoAF opened the world’s first fully automated mixed waste processing facility in 2016 in the village of Skedsmokorset, just outside of Oslo, to help meet the needs of Norwegian municipalities that were facing high labor costs. While the concept was three years in the making, Stadler needed just three months to complete construction of the facility.

RoAF collects household and food waste from 10 municipalities in Norway, including Skedsmo, which boasts a population of roughly 53,000 people. When waste arrives at the automated plant, it’s first fed onto a conveyor, which delivers the waste into the sorting plant.

Green bags of food waste are sorted from the rest of the material stream and taken to an on-site anaerobic digestion facility, where they’re turned into biogas, which fuels RoAF’s waste collection trucks. Meanwhile, residual waste, along with recyclable materials, pass through a screening drum and near-infrared (NIR) optical sorters, from Norway-based Tomra. Material is first separated by size in the screening drum and then into five types of plastic, mixed paper, metals and residual waste.

Plastics, metals and mixed paper are recovered at the facility for further recycling, while the waste is incinerated and used for nearby heating and electricity applications.

A new concept

High labor costs and Norway’s remote location were the main drivers behind the city of Oslo’s request for a fully automated mixed waste processing facility. The municipality put out a bid to design and construct the first facility of its kind and awarded the bid to Stadler Anlagenbau.

Mat Everhart, CEO of Stadler America, has toured the facility many times. He says at the time the plan was proposed, the automated concept was not only new to Stadler, but also “new for the world.”

“Essentially, the cost of labor to recycle outweighed the value of recyclables,” Everhart says. “They put out a bid to all the major European players for a system that was fully automated with no manual labor sorting required because it made financial sense for them.”

Everhart says people touring the $234 million facility always notice two things: the smell of the plant and how clean the fiber looks after sorting.

“The thing you hear about mixed waste processing is that it’s hard to get good quality fiber out of it,” Everhart says. “Any recycler I’ve taken to this plant couldn’t believe how good the paper looks and the fact that it didn’t smell.”

While construction of the plant was underway, the Norwegian municipalities redesigned their residential waste and recycling collection program. Municipalities chose bright green bags for food waste collection because of the optical sorters’ ability to identify the green bags from the rest of the material and waste, Everhart says. Much thought was put into the front-end design of the plant, which separates the bagged food waste and fiber from the rest of the material stream early in the process.

“The system has a very advanced amount of technology to separate the organic material, but also to get the fiber away as soon as possible so the material doesn’t absorb that odor,” Everhart explains.

"Any recycler I’ve taken to this plant couldn’t believe how good the paper looks and the fact that it didn’t smell.” –Mat Everhart, CEO, Stadler America

Norway’s collection system is also different from North America’s in that the country uses a three-bin collection system: one bin for food waste in green bags, plastic and residual waste; the second for paper and cardboard; and the third for glass and metal.

“The difference is rather than asking the consumer to do the first step in recycling, we’ve given them a way to separate [material],” Everhart says.

Operations at the plant were so successful that within one year of opening, RoAF completed a “major expansion” at the facility to increase capacity and open its doors to waste management companies and municipalities interested in delivering waste and recyclables to the plant.

Technology at its best

In all, the plant includes a variety of processing equipment, including 145 conveyors, 16 NIR optical sorters, two drum screens, one vibrating screen, a star screen, a shredder, two bag openers, two ballistic separators and an eddy current.

“It is all well-known technology but put together in a new way,” says Oivind Brevik, RoAF’s administration director.

One of the keys to achieving full automation at the facility was strengthening the front end of the system, which includes Stadler’s screening drum, and the addition of several Tomra optical sorters, which enables the plant to operate without manual labor on the sorting lines, although there are two employees on-site who are charged with monitoring the site’s machines.

“The real skill is our ability to know how to take our own equipment and integrate it with Tomra’s optical sorters,” Everhart says.

The facility processes 40 tons per hour. Of the mixed waste that is brought to the facility, 5,000 tons of recyclables are recovered annually, including 2,500 tons of high-quality plastics, including polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP) and film grades. Everhart says the material recovery rates at the automated facility are comparable to recovery rates at single-stream material recovery facilities (MRFs) in the United States, adding that fully automated facilities are feasible in the North American market.

Automation in North America

While Norway is home to the world’s first fully automated mixed waste processing facility, automation technology is increasingly being adopted at waste and recycling facilities in the U.S.

“There are MRFs that are highly automated that are already in place,” Everhart says. “The companies who lead the market today are using it, but they don’t advertise it. You have high automation already.”

The amount of labor used on sorting lines has changed drastically over the years in the industry. Ten years ago, the “industry standard” was to have at least 40 sorters in a 40-ton-per-hour system, Everhart says. Today, operators are using less manual labor in favor of automation to help offset challenging commodity prices and high operating costs, as well as to help with productivity and to increase quality.

“Over the years, it’s changed to a target range of about 20 to 30 laborers,” Everhart says. “In the last year, people are starting to flirt with three to four sorters in a facility.”

Everhart says, “MRFs are putting concepts and designs together” where there will be fewer than 10 people working in an average 35-ton-per-hour facility in the next year or two.

However, he notes that one of the immediate challenges to achieving full automation in North America will be the integration of robotic sorting technology into existing waste and recycling operations.

“The problem is that people utilizing robots are early adopters,” Everhart says. “The issue is not the technology or programming, but it takes people at the plant thousands of hours to figure out how to get it set up right. Manufacturers making the robotic sorters are just getting enough hours in real-life applications to get the kinks worked out. It’s definitely improving, but it’s not as quick as everybody would like it to be.”

The author is the digital editor for Recycling Today Media Group and can be contacted at kmaile@gie.net.