Over the past several years, mixed waste processing has gained a lot of attention. Stagnating recycling rates, high costs for collection and processing of solid waste and recyclables, concerns about single-stream recycling residue and the resurgence of interest in conversion technologies have attributed to this renewed interest.

Many cities are facing difficulty with implementing or improving recycling programs and some have looked into the opportunities posed by mixed waste processing.

Houston, using a $1 million grant from the Bloomberg Philanthropies Mayors Challenge, has been studying how mixed waste processing could benefit the city.

Other notable local governments that have looked into mixed waste processing include Montgomery, Alabama, and Indianapolis, Indiana. The opportunity for Montgomery was to improve its single-digit recycling rate without the expense of operating a curbside recycling collection program.

The opportunity for Indianapolis, which sought to partner with Covanta under its existing contractual arrangement, was to recover recyclables from residential waste and improve fuel quality for Covanta’s waste-to-energy facility.

The feedstocks for the Enerkem project in Edmonton, Alberta, and the Ineos project in Indian River County, Florida, rely on mixed waste processing to create a feedstock suitable for gasification.

So what are the results of these opportunities? To put it simply, they are mixed.

  • Houston — “One Bin for All” plans are under contract negotiations, but the current low commodity low energy prices may hurt the project’s chances.
  • Montgomery — The $35 million facility closed after 17 months of operation and due to the low commodity pricing. The facility owner, Infinitus, and Montgomery are seeking a resolution that may allow for the continued operation of the facility.
  • Indianapolis — plans for the mixed waste processing facility hit a few legal roadblocks, including a February 2016 ruling from the Court of Appeals of Indiana that Indianapolis violated procurement laws in awarding the project to Covanta.
  • Enerkem — successfully processed solid waste into a gasification feedstock in 2015 and created methanol. However, the system is not yet operating at full commercial scale.
  • Ineos — the project has been struggling with startup and commissioning since the facility opened in 2013.

Mixed waste processing technology has proven successful in recovering marketable recyclables where limited recycling existed and has shown to produce suitable feedstock for gasification and conversion to methanol. Substantial challenges remain, however, to the future of mixed waste processing, including low recyclable commodity pricing, low energy pricing, concerns about the quality of recyclables resulting from such systems and the lack of significant advancement in commercial scale conversion technologies.

Is there hope for such technology in the U.S.? Only time will tell. But as solid waste managers with the goal of improving recycling rates, recovering renewable energy from waste and reducing landfill disposal, we should keep mixed waste processing in the mix.

Gershman, Brickner & Bratton, Inc. (GBB), www.gbbinc.com, is an international solid waste management consulting firm based in Fairfax, Virginia, that helps public and private sector organizations craft practical, customized and technically sound solutions for complex solid waste management challenges.

John Carlton is a senior vice president at GBB. He can be reached at jcarlton@gbbinc.com.