The title of Bob Dylan’s song, “The Times They Are a-Changin,” is an apt description for developments in today’s waste-to-energy (WTE) industry. Although combusting municipal solid waste (MSW) to produce electricity has matured into a proven technology that has earned a place on the U.S. Environmental Protection Agency’s (EPA) integrated solid waste management hierarchy, the last traditional WTE facility — meaning a site that combusts MSW or that produces refuse-derived fuel to fire utility boilers — to begin operations in the United States did so in 1996.
However, recent years have seen expansions of traditional WTE facilities in Hillsborough County, Fla.; Lee County, Fla.; Honolulu; and Olmstead County, Minn. Other locations in the midst of procuring or developing proven technology projects are Frederick County, Md.; Harford County, Md.; Baltimore; Palm Beach County, Fla.; and the U.S. Virgin Islands.
Furthermore, many communities are starting to look at newer waste-to-energy technologies — known in the industry as “conversion” technologies — that produce vehicle fuel and electricity from MSW. Examples of these technologies include gasification and pyrolysis. Using the research of Gershman, Brickner & Bratton Inc. (GBB), a Fairfax, Va.-based solid waste consulting firm, this article will provide an overview of projects that are using these technologies. Despite mentioning some of these projects, GBB makes no endorsement of the companies involved or the technologies.
Several factors have contributed to this renewed interest in taking advantage of the energy value of MSW. Traditionally, the push has come because local landfills are at capacity and about to close, and there is community opposition to a new disposal site. These developments are taking place just as access to larger landfills in more distant locations grows. However, tipping fees are expected to increase in many locations., and as fuel prices rise, the cost to transport MSW to distant landfills only will grow more expensive.
More importantly, government policies are spurring the development of technologies that generate energy from MSW and biomass feedstocks. In his 2011 State of the Union address, President Obama called for reinventing the country’s energy policy and for setting a goal of obtaining 80 percent of the nation’s electricity from clean energy sources by 2035. The administration’s plan calls for a broad energy strategy that starts with research and includes grants, financing assistance and tax incentives. Among other initiatives, the plan calls for ramping up support for renewable energy with $341 million for the research and development of biofuels and biomass.
Even if the President’s plan does not pass Congress intact, government support is already making a difference in advancing waste conversion technologies. In 2009, the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA) awarded $564 million in grants for the research and development of technologies that produce biofuels and bioenergy; 19 of these projects use MSW or woody biomass as the feedstock of choice. Local governments around the country have started to take a fresh look at MSW-fed conversion technologies.
Exploring Conversion Technologies
Several communities have formally investigated advanced conversion, only to terminate projects as they learn that the technologies are not yet ready for prime time. Examples of these municipalities include New York, N.Y.; Broward County, Fla.; Sacramento, Calif.; San Jose, Calif.; Santa Barbara, Calif.; and Salinas Valley, Calif.
Meanwhile, other municipalities are forging ahead, some with and some without federal government loans or grants. Examples of these include St. Lucie County, Fla.; Three Rivers Region (Pontotoc), Miss.; Indian River County, Fla.; Lake County, Ind.; Los Angeles County, Calif.; and Taunton, Mass.
Canadian cellulosic ethanol producer Enerkem is constructing a $250 million waste-to-biofuels facility in Pontotoc, Miss., at an existing landfill owned by the Three Rivers Solid Waste Authority. The authority has signed an agreement with Enerkem to supply 190,000 tons of unsorted MSW per year. Using feedstock that includes woody biomass and biomass removed from MSW, the plant is designed to process 300 tons of waste daily and produce 10 million gallons of ethanol annually through gasification and catalytic processes.
Gasification is the heating of MSW to produce a synthesis gas (syngas), which consists primarily of hydrogen, carbon monoxide, carbon dioxide and some trace compounds. The energy or heating value of syngas varies from 200 to 500 British thermal units (Btu) per cubic foot, approximately half that of natural gas. After an extensive cleaning step where particulates are removed, the gas can be used as fuel or feedstock, or for production of other chemicals. While pyrolysis systems (heating without oxygen) are primarily focused on destroying waste, a gasifier is designed primarily to produce a usable gas.
Enerkem received a $50 million DOE grant for this project. When completed in 2012, the facility is expected to create some 130 jobs. Additionally, according to Enerkem, the project has obtained a conditional commitment in January 2011 for another $80 million loan guarantee from the USDA Section 9003 Biorefinery Assistance Program, which will eventually bring total production capacity to 20 million gallons of ethanol annually. In a recent round of financing, Enerkem raised $51.5 million from a syndicate of investors that includes Waste Management.
Vero Beach, Fla.
In February 2011, INEOS Bio of Lisle, Ill., and New Plant Energy of League City, Texas, broke ground in Vero Beach, Fla., on the first U.S. facility that will produce both ethanol and electricity from waste. When production begins in 2012, the $130 million Indian River BioEnergy Center will produce 8 million gallons of bioethanol each year and six megawatts of renewable power from local yard, vegetative (organic waste from forestry and agricultural operations) and household wastes, and from construction and demolition (C&D) materials. Two megawatts will be used to power approximately 1,400 homes in the surrounding community.
In addition to support from the state of Florida in the form of a $2.5 million grant, the project has received a $50 million grant from DOE and a conditional commitment for a $75 million loan guarantee from USDA as part of its Biorefinery Assistance Program.
The conversion process used at the BioEnergy Center combines gasification and fermentation. Organic waste reacts with oxygen to produce a syngas consisting of hydrogen and carbon monoxide. The gas is cooled, cleaned and fed to naturally occurring bacteria. The bacteria convert the gas into cellulosic ethanol, which is then purified for use as a transportation fuel.
Powers Energy of America, based in Evansville, Ind., also will use INEOS Bio technology for a $254 million “garbage to ethanol” plant it is developing in Schneider, Ind. The plant will produce ethanol and electricity using feedstocks including MSW, wood waste, agricultural waste and yard waste. In November 2008, Powers Energy announced that it had reached a 15-year waste supply agreement (with one five-year extension) with the Lake County (Ind.) Solid Waste Management District. Powers Energy also has secured multiple waste supply agreements with individual members of the district.
The facility is expected to receive a nominal 2,000 tons per day (TPD) waste supply to produce 1,000 TPD of processed materials as feedstock to be fed into the gasifier. According to reports, tipping fees at the plant will start at $17.50 per ton, and construction is scheduled for completion in mid-2013.
Storey County, Nev.
Fulcrum BioEnergy, Inc. of Pleasanton, Calif., is developing the $120 million Sierra BioFuels Plant, which will be located about 20 miles east of Reno, Nev., in Storey County. Fulcrum has been working with Fluor of Irving, Texas, on the engineering services for the project and expects to begin construction this summer. When the plant, which has already been fully permitted, opens in late 2012, it will be one of the first commercial-scale projects in the United States with the capacity to convert post-sorted MSW into ethanol, electricity and propanol.
On Jan. 6, 2011, Fulcrum announced that it had entered into a 15-year feedstock agreement with Waste Management of Nevada for the delivery of post-sorted MSW. This agreement supplements an earlier MSW supply arrangement with Waste Connections of California. The plant will use a plasma enhanced melter from InEnTec to gasify MSW. The project will create 53 full-time and more than 450 temporary jobs.
St. Lucie County, Fla.
Geoplasma, an Atlanta-based firm that is part of a conglomerate called the Jacoby Group, has been hired by St. Lucie County, Fla., to build a $125 million plant that uses plasma arc technology to process 600 tons per day (TPD) of MSW and up to 62 tons of tires. It will export 19 megawatts of electricity, enough to power more than 20,000 homes. Operations are expected to begin in 2013. Geoplasma’s plasma arc system is a pyrolysis or “starved air” process that generates heat by igniting the waste with a plasma torch to produce a syngas, which is then combusted to produce steam and electricity. At the core of a plasma torch is a pair of electrodes. An electric current arcs between the electrodes, turning the surrounding air into plasma by stripping electrons from their parent atoms. The heat and electric charge of the plasma vaporize the waste.
This “rubbish-to-syngas” plant will use a plasma converter to be supplied by Alter NRB/Westinghouse. Westinghouse has seen interest in this technology rise and now hires out its test facility in Madison, Penn., for $150,000 per day, according to a recent report in The Economist.
Los Angeles County, Calif.
Los Angeles County is currently conducting three pilot projects to demonstrate the technical, economic and environmental viability of conversion technology facilities, and to establish pathways for permitting and financing commercial scale projects. In January 2011, one of the three projects (operated by CR&R/Arrow Bio) received a $4.5 million grant from the California Energy Commission. Construction has begun on an anaerobic digestion facility sited at CR&R’s existing materials recovery facility in Perris, Calif. The project will process 150 TPD of post-recycled residual solid waste and convert the biogas generated into biomethane for the county’s truck fleet.
Mass Burn Technology
Even as new conversion technologies gain traction, mass-burn waterwall combustion technology still is the most common for large WTE facilities in the United States and overseas. Waterwall systems are fabricated on site and generally have larger unit sizes, capable of taking in between 200 TPD and 750 TPD of MSW. Much of the equipment is field-erected, requiring extended contracting schedules of 28 to 32 months. Covanta and Wheelabrator own and operate the majority of the privately-owned, mass-burn waterwall facilities in the United States.
Mass-burn starved air combustion technology uses less air than waterwall incineration, which leads to smaller equipment sizes. Modular, factory-built units can be set up onsite in a relatively short time, e.g., 18 to 24 months. These units have been built to process up to 150 TPD and are used for smaller WTE facilities and for industrial applications.
Frederick County, Md., and Palm Beach County, Fla., are both developing new mass-burn facilities, with plans for completion in 2015. Construction of Frederick County’s 1,500-TPD facility is scheduled to begin in 2012. The $668 million, 3,000 TPD Palm Beach County plant will be the largest renewable energy facility in Florida. It will use three mass-burn units of 1,000 TPD each to generate approximately 75 megawatts of electricity. The county will own the facility.
While public opposition to mass-burn facilities has been an issue in the past, both Frederick and Palm Beach Counties have sought to assuage concerns by reaching out to the community to explain the need for the projects. Palm Beach County’s information campaign was designed to reach government officials, local public works directors, homeowner and neighborhood associations, and environmental groups to explain the benefits of WTE over landfilling and to highlight the new facility as a renewable energy project. Frederick County has sought to address concerns about cost, emissions, traffic and aesthetics by posting all related reports and studies on the county’s website.
In a refuse-derived fuel (RDF) system, MSW is mechanically processed at the front end to produce a more homogenous and easily burned fuel designed to suit boiler requirements. Additional pre-processing can be applied to the incoming waste stream to remove other noncombustible materials, such as glass and aluminum. A separate waterwall boiler burns the fuel, usually in a semi-suspension system, allowing for a smaller, more efficient boiler. RDF also can be used as a replacement or supplemental fuel in existing solid-fuel-fired boilers, especially those fired by coal. RDF is considered a proven technology.
Locations with good examples of RDF technology in place and operating successfully include Ames, Iowa; Biddeford, Maine; Elk River, Minn.; Hartford, Conn.; Honolulu; La Crosse, Wis.; and West Wareham, Mass.
A good source of information on both mass burn and RDF technologies and companies offering them is the Energy Recovery Council, a national trade organization representing the industry and communities that own WTE facilities. The council’s members own and operate 69 of the 86 modern U.S. WTE facilities.
Consideration of any waste processing technology must include identifying the relative risks involved. In conducting a risk assessment, it is important to evaluate the following factors and answer questions such as the following about the company offering the technology:
• Overall track record, including operational commercial experience with the technology.
• Size and scale of successfully operating facilities.
• Environmental performance, including characteristics of emissions.
• Changes in state or federal legislation that might affect permitting and operations.
• Overall economics: What capital investment is necessary to achieve operating performance requirements? Has the solid waste stream been estimated accurately? Is waste likely to be diverted to competing facilities? What is the cost for residue disposal? Will the facility meet energy market specifications? What are the market specifications for any non-combustible recyclables? Will there be revenue from the sale of non-combustible recyclables?
• Reliability of the technology over time and whether the locality has an alternative disposal option in the event of downtime or technical failure.
• Financial strength of the vendor and its ability to offer full service arrangements.
Gasification and pyrolysis have little operating history processing MSW, compared with a long history of commercial experience for mass-burn combustion and RDF technologies. Although gasification, pyrolysis and anaerobic digestion systems are claimed to be superior to mass-burn systems, it is impossible to draw conclusions about their reliability based on the current limited operating record.
Still, new conversion technologies are showing promise, and government policies and funding support are in place to encourage their development. There’s a lot for the solid waste industry to keep its eyes on as these new projects begin operation, and their environmental and economic results become clearer.
Harvey Gershman is president of Gershman, Brickner & Bratton Inc. a Fairfax, Va.-based solid waste consulting firm. The firm is currently tracking over 500 companies offering waste-to-energy and waste conversion technologies, facilities and services, whose developmental stages range from engineering drawings and laboratory models to full-scale operating prototypes. Gershman can be reached at [email protected]
Waste to Energy (from Waste Management's YouTube channel)