MRF

MRFs Get Resourceful to Adapt to Changing Waste Stream

New innovations focus on ways to improve capture rate and material quality while reducing residues.

The waste stream is ever evolving, with new packaging, blended plastics, organics and other items each presenting unique processing challenges for material recovery facilities (MRFs).

Further testing the industry is that customers who buy these recycled commodities are demanding better quality. In response, MRF operators are retooling to best manage the stream and deliver clean, valuable products.

Several years ago, end users would accept almost any bale of the type of recycled materials that they depended on, even if it was fairly contaminated. But over time end users have adopted strict quality standards and clearly defined specs—to the point that they will reject or pay substantially less for bales containing too much trash. Meanwhile commodity prices, although up from bottom levels, remain near the low end of historical averages.

“So you have a changing inbound supply requiring facility upgrades to deliver quality bales. But with low commodity pricing there is rarely revenue to pay for those upgrades,” says David Hudson, director of sales and marketing for Recology, an integrated resource recovery company.

Hudson is among speakers who will be presenting at the MRF Innovations on Tuesday, May 9 at 11:00 AM at WasteExpo 2017 in New Orleans.

New innovations focus on ways to improve capture rate and material quality while reducing residues. Some of these innovations have been incorporated at Recology’s San Francisco MRF, where the company found an innovative way to improve capabilities while containing costs.

The company enhanced operations by retrofitting a processing facility using both old and new equipment to better manage the changing stream.

“We could use certain aspects of the existing facility while adding new technology to the line in order to adapt to changing quality and changing material types,” Hudson says. “The end result was our recovery rate went from 87 percent to 95 percent.”

Ultimately the improved system created less residue while yielding more materials to bring to market. The retrofit was far less expensive than building a new MRF. And operations continued, uninterrupted, throughout the upgrade.

Improved sorting has been perhaps the biggest industry uptick, specifically to separate plastics, fiber and glass.

“In the future I think we will see more material types that we will need to sort,” Hudson says. “We will see even more of a push toward creating higher quality bales.”

“And I think some MRFs will take a greater look at becoming vertically integrated [assuming control over several production steps],” He adds. “Given greater demands for quality and concerns from foreign buyers … more and more facilities will likely begin evaluating options to further upgrade the materials they collect.”

A push for organics diversion is opening up new territory for MRFs, but this trend comes with a steep learning curve.

“We understand the economics and technology that enables diversion of plastic, metals and paper, but the big unanswered question is, what do we do about the organic fraction in a way that makes economic sense?” says Ken Beaver, director of Processing Solutions, Environmental Solutions Group, an equipment manufacturer. Beaver will also present at the WasteExpo session.

Determining how to balance collection and processing has been key to improving the system.

Some municipalities add an extra cart to collect source-separated organics, but this requires extra routes and more trucks.

“While the program may be successful in terms of collecting and diverting food waste, it comes at a high cost. And along low-density routes in particular this is expensive,” says Beaver. Further, a truck’s gas emissions may outweigh the environmental benefits of diverting a small amount of food waste.  

One alternative is to take food comingled with trash and separate it at the MRF (sometimes called an organics processing facility in this scenario). But this method comes with a high processing cost as it requires advanced technology.

Some municipalities are beginning to balance collection and processing expenses by collecting food in bags that go in trash bins, which are pulled out at sorting lines, then sent to compost facilities.

Even with these bags and source separation there will be organics comingled with trash.

“The question now is, how can you economically separate and recover that organic fraction,” says Beaver.

Beaver will show technologies that can be added to a MRF that he says are proven to efficiently and economically recover organics when they are comingled with other trash.

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