The new plant referred to as PBREF#2 can process a million tons of municipal solid waste annually producing electricity and reducing the waste sent to the county’s landfill by up to 90 percent. (Landfills generate methane which is 21 times more potent of a greenhouse gas than carbon dioxide.) B&W will supply three mass burn boilers, grates, ash and metal recovery systems and emissions control equipment with KBR providing the balance of plant equipment and construction services. The new plant employed about 700 during construction, will have 175 permanent staff and will also include a LEED Platinum Visitors Center.
The plant is adjacent to SWA’s 52 megawatt PBREF#1 built by B&W and Bechtel in 1989. The Stirling boilers were replaced in 2010. “We’d typically do 860,000 tons; after the refurbishing, we did 900,000 tons,” said Bill Arvan. B&W’s operations and maintenance contract was extended to 2029.
Arvan, a chemical engineer who holds an MBA from Florida Atlantic University, explained the operation of the WTE plant and conducted a tour for World- Gen to point out the differences between Refuse Derived Fuel in PBREF#1 and the Mass Burn for PBREF#2. “On mass burn facility’s, recovery of non-ferrous and ferrous metals is performed post-combustion. This differs from an RDF facility in which ferrous and non-ferrous metals are recovered both during the processing of MSW into RDF and post combustion,” Arvan shared.
General Facility Manager,
B&W’s Palm Beach Resource Recovery Corp
“The fuel arrives on the tipping floor from six transfer stations hauled by SWA tractor trailers subject to 80,000 lb road limits. SWA receives about 500 loads a day or 1,000 trips daily,” he said. Three procedures take place in the Refuse Derived Fuel (RDF) preprocess to remove hazardous materials, household materials and appliances before the conveyor carries it to the shredder. Overhead magnets sort out ferrous metals, recyclables and coins before going into the two Stirling boilers, he explained. The chemically inert bottom ash is combined with fly ash and sent to the landfill.
Ferrous metals [contain iron] are sold to Trademark Metals who essentially nuggetize the material and ship it out on rail cars,” he added.
Non-ferrous materials are melted down and made into ingots. Last year, SWA sold more than 79,000 tons of recyclables and recovered coins accounting for $100,000.
SWA has recycled more than two million tons of residential and commercial material that otherwise would have been landfilled. In addition to recyclables, SWA recovers nearly 250,000 tons of clean vegetation annually which is mulched and either composted, processed into boiler fuel, or returned to the land as a soil amendment.
In answer to a question, he said the plant operates 120 hours a week and stores the fuel on site, though the power plant is operating 24/7.
The new facility will reduce 63 percent less carbon dioxide, 94 percent less sulfur dioxide and 62 percent less nitrous oxides that the traditional coal fired power plant. For every ton of municipal solid waste processed, one barrel of oil or ¼ ton of coal is saved and one ton of GHG avoided. The facility will save 1.9 billion cubic feet of natural gas annually.
As the EPA has specific emissions limits for facilities that combust waste to produce energy, the Solid Waste Authority is incorporating the most modern and most sophisticated air pollution control systems of any facility of its kind in the world. All of the emission levels from the PBREP#2 will be below the Federal standards, with the performance of the emissions control equipment guaranteed by the manufacturers and by the facility operator.
SWA’S ADDED VALUE
The SWA constructed a $40 million, 138,000 square foot Recovered Materials Processing Facility (RMPF), the largest in Florida. This facility allowed the SWA to expand the material accepted in the recycling program to include all cardboard such as dry food boxes, beverage cartons and tissue boxes. The expansion of materials also included junk mail and steel cans, further reducing reliance on the landfill.
At the SWA’s Biosolids Pelletization Facility (BPF), landfill gas is used to power the sludge dryers as an alternative to natural gas. The SWA and its partners constructed this facility to provide for the disposal of sludge from waste water treatment plants. At the BPF, sludge will be dried, pelletized and sold to fertilizer blenders as a natural and nutrient rich component of commercial fertilizers.
SWA’S REVENUE STREAM
The Solid Waste Authority of Palm Beach County is in a unique position to lower its customer rates for up to 7 years, while adding an estimated $45 million economic boost to the county’s economy. PBREF#2 was permitted to process 1 million tons of material a year. Given the county’s current population and waste generation, in the first year there is capacity for an estimated 200,000 tons of additional waste within this permitted capacity. So, in an effort to maximize the facility’s use and maximize revenue, the Solid Waste Authority is exploring options to import waste from neighboring counties to fill this deficiency.
The ultimate decision if the Solid Waste Authority will import out-of-county waste will be made by the SWA Board, after holding public meetings which could be as early as 2015. Nothing in the Palm Beach County Solid Waste Act or any other legislation prohibits SWA from either importing or exporting solid waste.
The State of Florida counts waste delivered to a Renewable Energy facility towards the State’s 75% Recycling Goal, and the State provides one ton of recycling credit for each megawatt hour of energy produced.