Launch Slideshow

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Smart Gamble

Smart Gamble

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    The grapple operator first mixes the material by redistributing the garbage evenly. Once the mixture is optimal for combustion, a claw picks it up and drops it into the furnace feed hopper. This grapple moves about 8,000 pounds/lift.

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    The boiler steam drum is suspended from steel hangers about 100 feet above the facility floor. Photos: Lee County Solid Waste Division

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    Once the high-pressure steam has passed through the turbine generating electric energy, the remaining low-pressure steam is condensed to water and recirculated through the boiler.

Faced with the possibility of working with a potentially bankrupt partner on a facility expansion, the Lee County Solid Waste Division in southwest Florida took the unusual step of assuming full procurement and performance risks for the $119 million project. By executing more than 55 procurement contracts, the division shaved an estimated $5 million to $7 million from the overall price.

The division has been a leader in other ways since its inception in 1989, having created an integrated waste management system that included two incinerators used in an energy recovery component. To limit the amount of material sent to its landfill, the division also does recycling, curbside electronics collection, free mulch distribution, and a household chemical waste program.

In 1990, the division selected Covanta Energy (formerly Ogden Martin Systems) to design, build, and operate a 1,200 ton/day waste-to-energy facility for 20 years. The facility has a ferrous and nonferrous metal recovery system for metals recycling and produces approximately 36 megawatts of electricity.

Despite aggressive recycling programs, by the year 2000 population growth forced the division to look for more disposal capacity. It decided to add a third combustion unit with a boiler and a second turbine generator.

The Florida Department of Environmental Protection issued a Prevention of Significant Deterioration (PSD) permit allowing the facility to incorporate a mass burn grate system manufactured by Martin GmbH. Energy efficiency of the German company's moving grate and combustion-control system is similar to medium-pressure coal combustion units.

Popular in Europe, Martin's system meets strict European Community standards for air emissions similar to the EPA's requirements under the “New Source Performance Standards” that limit the emissions of sulfur dioxide, nitrogen oxides, and particulates. It was the first refuse combustion unit to be permitted under these more stringent standards during the previous 10 years.

Meanwhile, Covanta had filed for bankruptcy. Because the outcome of bankruptcy proceedings was uncertain, the division decided to build the new unit on its own, using Covanta as a design adviser and making other decisions on procurement and contract strategies that differ from the typical contract procedures for similar projects.

A DEARTH OF SUPPLIERS

In addition to the bankruptcy, two other developments complicated the project: Hurricanes created equipment and labor shortages throughout the region and increased costs for critical commodities such as concrete and steel, and many waste-to-energy equipment suppliers had vanished (see sidebar on page 40) since the division bought its first incinerator in 1990.

Suppliers for all equipment were eventually found, but the number of qualified contenders had fallen significantly.

Stoker technology and equipment supply was sole-sourced to Martin; the rest of the equipment was competitively bid using principals set forth in a “Basis of Design” (BOD) document developed between Covanta and the division. Burns & Roe Inc. of Oradell, N.J., was chosen as the architect/engineer to provide engineering, design, and procurement consulting services to the county.

Long lead items were bid and awarded to:

  • Mitsubishi Heavy Industries for a 20-megawatt turbine generator
  • Babcock Power Inc. for boiler supply and erection
  • Alstom Power and Fuel-Tech for air pollution control.

The balance of plant equipment (such as pumps, electrical transformers and switchgear, conveyors, ash-handling components, water treatment systems, cooling tower, heat exchangers, valves, etc.) was specified, bid, and bought by the division.