Glass Works: Best Practices for Producing Quality Recycled Glass
Effective program funding, advanced sorting technology equipment, proximity to end markets and consumer incentives are helping programs succeed.
The collection of all recyclables at the curb in one bin, called single-stream recycling, has become the practice for most communities. For the most part, these programs present challenges for the recovery of high-quality glass, which can be used in the manufacture of new glass bottles and jars. However, a few community programs are proving successful at producing an end product suitable for making new glass containers and other end markets.
Two programs, one in Seattle, Wash., and the other in Dayton, Ohio, have managed to establish programs that are able to sort through a large quantity of mixed recycled materials while delivering a quality recovered glass product for closed-loop end markets. What are they doing right? Effective program funding, advanced sorting technology equipment, proximity to end markets, and consumer incentives are all helping these programs succeed.
High- and Low-Tech Unite
Since 2009, the city of Seattle has offered single-stream recycling to its residents. The Materials Recovery Facility (MRF), operated by Allied Waste, is leading the way in single-stream processing capabilities. While processing roughly 17,000 tons of glass, cardboard, paper, plastic, aluminum and other metals per month, the facility achieves a diversion rate of 96%.
The MRF is able to accomplish this volume and efficiency by combining high-tech equipment and traditional sorting methods to process the mixed recyclables into the cleanest-possible end products. In addition to the high-tech advances at the MRF, there are still more than 30 sorters on the line separating materials to ensure quality control. Recycling loads go through 2,000 ft of conveyors, belts and screens, and are then separated into nine recyclable commodities. This process results in greater processing and capture efficiency, as well as less residual waste.
The MRF also uses one of the most advanced glass processing systems in the nation, which includes negative air aspiration technology. This permits the plastic, paper and glass to be in the same waste stream rather than being separated. Through the use of a negative air aspirator and a series of shaker screens, light fraction paper and plastic is separated from the mixed glass, producing clean cullet (furnace-ready recycled glass).
The MRF’s efforts also benefit from a close proximity to end-use manufacturers, saving on transportation costs. For example, the Ardagh Group operates a wine bottle and food jar manufacturing facility that sits within an industrial zone just south of the city.
Public and Private Funding Boost Processing
In Dayton, Rumpke Recycling has successfully used both private and public funding to improve glass sorting and processing. At its local facility, it combined $4 million of private investment with a $500,000 grant from the Ohio Department of Natural Resources to expand its regional glass processing facility. While grant funding for recycling programs has seen reductions across the country due to stressed and shrinking state budgets, available grants greatly increase the likelihood of additional private investments.
The recycled glass resulting from the upgraded Rumpke processing systems is high quality, and the cullet is purchased by nearby glass container and fiberglass companies for use in the production of new products. The facility draws from both commercial and residential single-stream programs, and processes roughly 40,000 tons of recycled glass annually.
The Rumpke system also benefits from a privately owned “buy-back” system, where consumers can bring their recyclable materials, including glass containers, for cash. Rumpke developed and operates this unique program, which reduces unwanted trash and other non-recyclable materials that would otherwise need to be sorted out at its facility. This creates a clean stream for recycled glass that is similar to states that operate beverage container recycling refund programs.
More sharing of effective glass recycling and recovery best practices in local communities will support the improvement of single-stream recycling programs, as well as the technologies to sort mixed recyclables for the highest and best use. Recycled glass—and all recycled materials—will benefit.
For more information, visit www.GPI.org.
Any views or opinions expressed in this column are those of the author and do not represent those of Ceramic Industry, its staff, Editorial Advisory Board or BNP Media.