LANDFILL: Mill Weaves Landfill Gas Power into Production

Elizabeth Treadway

One North Carolina textile manufacturer has gained a new respect for landfills. Cone Mills Corp., Greensboro, now is using the methane gas generated at the city-owned facility to manufacture denim and consumer products at its White Oak plant.

This landfill gas (LFG) recovery project, a partnership between the city of Greensboro, N.C.; Duke Engineering and Services (DE&S), a subsidiary of Duke Energy Co., Charlotte; and Cone, also helped the city meet new regulations without a capital outlay or taxpayer financing.

After reviewing the 1995 Clean Air Act's New Performance Standards, the city discovered that it had to change the way it managed the methane gas generated at its White Street landfill. Previously, the gas had been passively vented.

To meet the new guidelines, the city's options were to:

* Flare the gas. This was the least desirable option because it required a $3 million capital investment while consuming the methane's energy potential.

* Generate electricity. This alternative was given serious consideration especially as the city received more offers from private contractors. While feasible, this alternative was expensive ($4 million estimated capital costs) and had a low rate of return on investment.

* Supply energy to an end user. This alternative resulted in a partnership between Duke Engineering and the city. Tax credits provided DE&S with the return on investment while offering a continuous revenue stream from the sale of the gas.

This met the city's objectives of using gas for energy while addressing the Clean Air Act. The partnership allowed the city to avoid the collection system's capital investment, while providing a royalty payment for the gas rights transferred to DE&S.

During project development, DE&S was conducting boiler realignment at Cone Mills. If the LFG could be piped to the plant without further treatment, capital investment could be minimized. Cone Mills agreed to have the boiler converted to burn the gas and was enthusiastic to use a less-expensive supplemental boiler fuel.

Work began in December 1995, and one year later, LFG was piped to Cone Mills' White Oak Plant.

In the agreement, the city transfers the rights of the gas to DE&S for 12 years, until the year 2007. DE&S is responsible for the pipeline operation and collection system, including well design and installation. The city is paid a royalty from the sale of the gas, based on British thermal units.

Currently, the collection system includes 86 wells with an additional 20 wells to be added by the end of 1998. Daily, the system generates 2.2 million cubic feet of gas, with the potential of producing 3.5 million cubic feet, which addresses Cone's supplemental power requirements.

A flare was installed for emergency use and for when the boilers aren't being used. The blower, used to move gas through the pipeline, is enclosed to reduce noise and to provide a protected area for instrument panels and for maintenance.

Total projected costs for the system is approximately $5 million. Greensboro's investment was the initial feasibility study, as DE&S provided all the capital to build the system. The city receives royalty payments, which increase over the contract period.

The city and Cone Mills received Duke Energy's "Power Partner" award in January 1997 for their collaboration in using LFG.

When the contract expires in 2007, the LFG system's ownership transfers to the city. Then, the city can either operate the system or contract it out.

Over the next year, the city will develop its gas management plan for a new disposal cell that opened December 1997. A number of opportunities exist for using the methane generated in this new cell, including providing energy for the landfill.

New Office Rust Environmental & Infrastructure Inc., Baltimore, has opened a new office in downtown Baltimore. The main telephone number is (410) 385-1434.

Request for Proposals The American Forest and Paper Association (AF&PA), Washington, D.C., Agenda 2020 Recycling Task Group has issued a request for preproposals (RFP) for fiscal year 2000. Agenda

2020 is designed to stimulate innovations and environmental improvements in manufacturing and forestry. The deadline for submitting a two-page preproposal is August 1, 1998. Research aimed at reducing energy use, improving fiber yield and eliminating stickies contamination is encouraged. For a copy of the RFP, fax a request to the AF&PA, Attn.: Cindy Tabb at (202) 463-2423. Information also is available on: www.afandpa.org

Recycling Watch: Food and Consumer Products * Chesebrough-Ponds saves roughly 240 tons of polyethylene, 2 tons of polypropylene and 40.4 tons of styrene on packaging annually. Likewise, cartons for Lipton Soup Secrets, Recipe Secrets and Cup-a-Soup are made from 100 percent recycled paperboard (35 percent of which is post consumer).

* Nestle USA packages its Taster's Choice Freeze Dried Coffee, Carnation Instant Breakfast, Libby's Pumpkin, Oretaga Mexican food products, Mighty Dog dog food, Fancy Feast cat food and Friskies and Alpo dry cat foods in recycled materials, be they glass, aluminum, steel or paperboard. Overall, Nestle reduced the amount of materials used in its packaging by more than 2,500 tons in 1996 alone.

* By using a 84-percent recycled-fiber shipping, The Wm. Wrigley Jr. Co. reduced the amount of pure virgin fiber used in its corrugated shipping containers by 2,300 tons per year. Wrigley also is testing the performance and durability of a 15 percent lighter shipping container.

* Packaging for Nabisco's Snackwells and Ritz crackers and Cream of Wheat are made of 100 percent recycled board. Grey Poupon and A1 are packaged in recycled glass. Similarly, Fleischmanns Fat-Free Buttery Original and Parkay Buttery Spray are packaged in recycled polyethylene.

* In 1996, Coors Brewing Company increased the recycled content of its aluminum cans to 69 percent, representing more than 40,000 tons of packaging material saved; and glass bottles to 23 percent, a diversion of more than 71,000 tons. Coors' stainless steel kegs contain 50 percent recycled material as well.

Source: Grocery Manufactures of America, Washington, D.C.