The Recycling Status of Container Glass Material: Recycled Glass ssue: Glass container recycling has
been having variable success
in recent years. Production
in the glass container industry has been flat or slightly declining
on a per capita basis, while recycling programs are collecting increasing
percentages of generated glass. This Best Practice discusses the
status of glass recycling on the national level.
Best Practice: According to the Glass Packaging Institute, approximately 10.6 million tons of glass containers (41 billion containers) were manufactured in the United States in 1995, representing approximately 6% of the U.S. municipal waste stream by
weight. Of that total, the
U.S. glass industry estimates that 63% is flint (clear), 25% is
amber (brown), 10% is green, and 2% is blue or other colors.
Generation of waste glass containers is actually greater
than container manufacturing because of importation of glass packages
for products like beer and wine. A large percentage of imported containers is
green, so the percentage of glass in the waste stream is closer
to 57% clear, 25% amber, and 18% green.
Franklin Associates(1) estimated that the total
amount of glass containers entering the waste stream domestically
declined from 14.0 million tons in 1980 to 12.1 million tons in
1994. The overall decline
in glass packaging has been attributed to the increased use of other
types of packaging, including plastic and aluminum. Also, some of the decrease in total generated
glass may be due to the manufacture of lighter bottles.
Major opportunities for glass recycling include the
following:
Container Manufacturing
Container manufacturers have
always known that melting recycled glass with virgin materials lowers
kiln temperatures and increases homogeneity of the entire batch. The manufacturers originally processed, or
“beneficiated,” recycled cullet themselves.
As recycling infrastructure has grown, most manufacturers
have moved away from internal processing of glass cullet, to buying
cullet through third-party processors who interact with the recycling
community. As of 1995, 66 glass container manufacturers
operated in 27 states in the United States.
From 1987 through 1993, domestic glass container manufacturing
plants increased purchases of cullet by over 95% by increasing the
percentages of recycled glass in new containers.
In 1993, a total of 2,432,463 tons of recovered glass were
purchased for the production of new containers.
The maximum value of recycled glass to container manufacturers
is approximately the substitution value for the virgin materials
it replaces. There are some
other issues of lowered energy consumption and longer furnace life,
but these factors operate at the margins.
One study(6) estimated the ceiling price for beneficiated
cullet at $45 to $60/ton, with no great changes expected.
Some states have passed laws requiring glass container manufacturers
to use a minimum percentage of recycled glass in the production
of new containers. In
Oregon, for example, glass container manufacturers were required
to use at least 35% post-consumer cullet by 1995.
California has even more aggressive laws requiring glass
manufacturers to increase use to 65% recycled content by 2005. These requirements have resulted in temporary price spikes in some
parts of the country.
Fiberglass Insulation
Trends in fiberglass insulation manufacturing
show increased consumption of mixed-color cullet. In 1993, approximately 350,000 tons of cullet were bought by the
fiberglass industry, or 4% of the total. Due to inconsistencies in the supply
of recycled glass, fiberglass insulation manufacturers have been
tentative in using glass cullet.
However, California content requirements and federal procurement
guidelines for purchasing fiberglass insulation with recycled content
have increased the motivation for cullet use in fiberglass.
Fiberglass insulation manufacturers have two primary concerns
about cullet quality: 1) fiberglass manufacturing is more sensitive
than container manufacturing to contaminants and to differences
in the composition and color of glass; and 2) boron, the most expensive
ingredient in fiberglass, is not found in glass containers.
Alternative Markets
- Numerous
other markets are being investigated across the country for recycled
glass. For information related
to a number of these specific applications see
the CWC Best Practices INDEX. The only alternative that consumes significant
volumes nationally at this time is the use of glass as a construction
aggregate.
Implementation: Local recyclers should build
a total cost model for their situation, taking into consideration
all of the costs of collection through processing and transportation,
and weighing market options based on those alternatives, while always
keeping an open mind to new market options.
Benefits:
Knowledge
of market opportunities is critical to maximizing revenue and identifying
appropriate recycling program design.
This best practice provides an overview of major market opportunities
and should be balanced by identifying the realities of regional
infrastructure.
Application
Sites: Recycling
Programs, material recovery facilities
Contact: For more information about
this Best Practice, contact CWC mailto:info@cwc.org.
References:
1)
Characterization of Municipal
Solid Waste in the United States 1995 Update, Franklin Assoc., 1996.
For the latest edition, see the EPA web site.
2)
Glass Container Market Recovery
Study,
prepared by SWANA, with the
EPA and GPI, Dec. 1995.
3)
Glass Composition and Breakage
in a Commingled System for Curbside Handling, Joe Paradiso, Consumers Glass,
July 1995.
4)
Optimizing the Collection of
Glass Containers, Shaan Kervis Hamilton, Resource
Recycling, 7/95.
5)
Sorting Glass Collection Differences,
Recycling Today, May 1996 issue, page 58.
6)
Recycled Material Prices -
Two Decades Past and Future, Clean Washington Center Rpt #C8, 1994. Issue
Date / Update: November
1996
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