A Solid Approach to MSW Fuel

The concept of solidifying preprocessed municipal solid waste into fuel pellets or briquettes is not new, but the market has been slow to mature.
By Katie Fletcher | April 23, 2015

People who burn their trash do so for various reasons, the most common of which are convenience in avoiding a haul to a local disposal site, and bypassing the cost of a regular waste collection service. Backyard burning is discouraged by the U.S. EPA, however, because of harmful dioxins that are released into the air. This raises questions as to how a solid, MSW-based fuel created from that very trash could result in a positive environmental impact when combusted, but there’s a difference between the two methods, and it all comes down to how the waste is treated and where it is burned.

A number of steps are involved in densifying MSW to produce fuel pellets or briquettes, also referred to as refuse-derived fuel (RDF) or solid-recovered fuel (SRF). The process essentially changes the physical form of the waste, enriching its organic content by removing the moisture and inorganics. End markets for the fuel include coal and biomass plants, cement kilns and industrial thermal boilers.
Besides incineration, raw MSW can be used for conversion technologies like pyrolysis and gasification.
RDF debuted when the oil shortage of the 1970s sparked interest in processes that could take advantage of the energy content in MSW. EPA demonstration grants helped fund a number of waste-processing projects that included RDF. As a result, facilities were built during the last few decades of the 1900s, but few have continued to operate through this century. Still, there are producers in the U.S. and new projects on the horizon.

RDF and SRF are more widely recognized in the United Kingdom. In Europe, there is the European Committee for Standardization (CEN) and technical committee (TC), which established all necessary standards for SRF under CEN/TC 343. The standards were created to promote free trade of these fuels in the internal market, as well as help equipment providers and permitting authorities build acceptance and trust amongst the public.

The EPA has published definitions, assessments and tests regarding RDF and its cofiring attributes in thermal units, and there are independent North American laboratories testing the fuels. Some companies have tested their fuel product against the European standard as well, but without specific quality thresholds in the U.S., questions remain about the product’s quality, emissions and consistency. Despite that, producers in the space seem confident in the fuels’ present and future market potential. A few U.S. enterprises creating solid fuel from MSW include Tennessee-based WastAway, America First Inc.’s project in Maryland, and New Bedford Waste LLC in Massachusetts.

Fuel Familiarity
WastAway began processing MSW in 2003, at its commercial facility in Warren County, Tennessee, using a patented process to create a product called Fluff. According to Terry Moore, chief business development officer with WastAway, the material that comes out of the process is basically free of metals and most of the inert materials, including ash from glass, rocks and dirt. Trash is first shredded, then the metals and inert material extracted, leaving the organic portion of the MSW. “Those things are shredded again, and they go through the hydrolyzer, which is a continuous-flow autoclave that runs at a higher temperature and pressure than an autoclave for sterilizing surgical instruments,” Moore says. “The reason we do that is to kill anything that is in the waste, any kind of pathogen.”

Around 2009, the company fired up its commercial facility in Morrison to pelletize its Fluff product, after the idea was suggested by WastAway shareholder Battelle Institute, an applied science and technology development company. Densifying aided with gasification, but the genesis of the move was for easier and cheaper shipping and handling. “It has the same Btu value whether it is pelletized or not, it is just a matter of whether the plant is close enough,” Moore says. “If you have to ship it a long distance, Fluff is maybe 15 pounds per cubic foot, and pellets are 35 or 40 pounds per cubic foot, so you get more pellets on a truck, and you still pay the same amount for freight.”

Since then, the company has tested the product with engineering companies and labs. According to Moore, the product is “amazingly consistent,” usually about 8,700 Btu per pound, varying between 8,500 and 8,900 Btu per pound. The material has been tested to the European CEN/TS standard. According to Moore, the scaling system is rated one to five in three different categories—Btu value, chlorine content and heavy metals. The poorest score being all fives, Moore says WastAway’s fuel generally qualifies as two-two-one.

 Last year, WastAway completed testing in Canada, the purpose of which was for Canadian power companies to determine whether the fuel behaved similarly to coal. “They found that it does, that the ash that’s generated from combusting this material is a little bit improved from the ash that you would get from coal,” Moore says. “They were also shown that it completely combusts in the firing zone—there are not any residual, noncombusted parts—and that it pulverizes just like coal will pulverize for a pulverized coal boiler.”

The testing results sparked interest in some Canadian provinces where CO2 emissions are very stringent, Moore adds. “If they burn 5 to 10 percent blend of our material with coal, they could get enough carbon credits to lower below the emission levels so they can continue to operate these large, electrical facilities,” he says.

Depending upon the location of a community or company, WastAway pellets may qualify for carbon credits, greenhouse gas (GHG) credits, renewable energy credits, recycling credits, landfill diversion credits and renewable portfolio standards certificates. Other sources of revenue can include tipping fees, ferrous and nonferrous metal sales, glass and inert sales and Fluff or WastAway pellet sales. “We look at all of the garbage that comes out of the back of the garbage truck as having value—we want to get all but the oink out of the pig—so we are looking at recovering everything there is,” Moore says.

Besides cement kilns and pulverized coal boilers, gasification is another outlet the company is marketing to, for creation of power, biofuel or chemicals.

Moore says companies that operate on coal usually value Wast-Away pellets on a relative Btu basis with coal. “If you had 11,000 Btu of coal selling at $60 a ton, you would probably see our pellets selling at $40 or $45 a ton,” Moore says. “It just depends on the value of the coal and the price they’re paying for that coal, as to what the customer will be willing to pay for the pellet.”

Although WastAway has been actively marketing the process to sell the equipment and license the technology, the company has just two commercial operations—the one in Warren County and one on the island of Aruba. “We don’t have any other plants at this time, but I can tell you if we talk this time next year, there will probably be five to 10 sales that we have completed,” Moore says. “We’re always looking for places that can support the process, both from a raw material standpoint and as a user for the output.”

One example is a project at Drayton Valley’s municipal landfill in Alberta, Canada, where testing will resume. According to Moore, the project was held up when a power company suspended testing the pellets in a pulverized coal boiler due to economic issues, particularly what the carbon credits would be valued at.

Model Landfill Project
Over the past few years, the 40-West Landfill in Washington County, Maryland, has experienced several hardships that have caused long-term financial strain on the operational tipping fee revenue. Some of these strains include an increase in recycling rates leading to decreased tipping revenue, the economic downturn resulting in less materials needing disposal, and the county landfill’s position surrounded by competitive, privately owned landfills. All these factors compounded, reducing the waste coming to the landfill to under 300 tons per day. The county decided the solution was a public-private partnership and after assessing a number of companies, it selected Green Kinetics Gateway or America First Inc.

The project was first announced in August 2013, but an extension was needed. Changes in the permitting approach by Maryland Department of the Environment required both phases of the project to be permitted for the federal and state air permits at one time in the third quarter of 2014. “The developer had to modify the schedule and incorporate the design and equipment selection into the phase-one permitting process,” says Julie Pippel, Washington County director of environmental management.

According to Pippel, the county now anticipates permit acquirement late this year. Construction, which will last six to eight months, will begin soon after. The project will cost nothing to the county, and AFI will be the sole signer of the loan, so the county bears no upfront financial risk for construction or operational expenses associated with the project. Phase one of the project will include AFI’s construction of a waste-to-energy (WTE) facility on 15 acres of the 40-West Landfill site. This facility will handle up to 500 tons of MSW landfill deliveries per day to create pelletized RDF, with the possibility of future expansion. “Converting MSW into RDF will not only reduce the volume of solid waste placed in the landfill by 95 percent, it will generate revenue while eventually lowering expenses such as leachate management,” Pippel says.

The second phase of the project includes the construction of a Fischer-Tropsch synthetic fuel plant to transform RDF pellets into high-energy gas, which will then be converted into transportation fuels. This phase will begin construction 18 months after phase one, and is estimated to take 12 to 18 months to complete, with production expected within 90 days of commissioning. The county says it anticipates approximately 10 percent of the pellets produced at the facility will feed the gasification plant, and the remaining pellets will continue to be sold into the market. At full production, the planned capacity is approximately 700 barrels of FT fuels per day. As part of this phase, the existing 40-West Landfill will be mined to recover buried MSW.

The county will receive a portion of the revenue from both project phases. Using today’s market value for RDF pellets, Washington County’s estimated share of net profits would be in excess of $50,000 per month from phase one, and in excess of $200,000 per month for phase two. This will be AFI’s first use of the technology on a commercial scale to date. “This innovative approach in processing MSW will position Washington County ahead of the curve to comply with upcoming federal and state regulations; furthermore, the county will serve as an international benchmark in environmentally responsible waste management,” Pippel says. “The goal is not only to make this project noteworthy in Maryland, but also nationwide.”

New Bedford’s Briquettes
While the WTE facility in Maryland is slated for construction later this year, a project in Massachusetts anticipates construction completion in October or November. New Bedford Waste Services, a sister company of ABC Disposal Service Inc., is building an MSW-recycling and RDF briquette-manufacturing facility in New Bedford. This facility will be known as Zero Waste Solutions LLC. NBWS currently has a construction and demolition (C&D) recycling plant and transfer station in Rochester known as the Rochester Environmental Park. This plant is permitted to accept 1,500 tons of MSW and C&D debris per day. The planned 103,000-square-foot ZWS operation is being built at the location as the end-disposal outlet for the C&D transfer station’s MSW and residuals. The ZWS facility will initially take in about 850 tons per day of waste and produce about 300 tons per day of briquettes valued at about $60 per ton.

The facility is estimated to achieve 90 percent or more recycling rates, which, according to Michael Camara, president of NBWS, will be the highest in the surrounding area. The RDF briquettes are called EcoTac fuel briquettes, created using WERC-2 Inc.’s patent-pending process. The EcoTac fuel is said to guarantee over 10,500 Btu per pound with limited moisture content and predictable outputs for cofiring with coal or woody biomass.

According to WERC-2 Inc., the fuel briquettes contain virtually no mercury, and when compared to coal average over 90 percent in sulfur reductions, 78 percent in ash reduction and cut CO2 emissions by 17 to 22 percent. All of the fuel’s testing data was provided to the EPA, and, according to Camara, the fuel briquette was approved by the EPA as a nonhazardous and nonsolid waste fuel. The fuel will be sold to biomass and coal-burning plants and cement kilns.

All in all, emerging projects demonstrate RDF potential, and those involved believe it can compete with other fuels in the market. NBWS and WastAway claim their products have a better shelf life than wood pellets. “The pellets that we make, because there is no active microorganisms in them, have a shelf life that is infinite,” Moore says.

These companies also say their products are odor free, and are on par with the consistency of coal or wood pellets.

For now, however, the market is much narrower for RDF. Players in the space agree RDF use will expand, but only commercially—not on the residential side. “Inherent in garbage are some things that you would need a more sophisticated emission control system for than what you would find in a household stove,” Moore says. “When you burn wood you just get CO2 and water for the most part, maybe some VOCs, but with burning garbage you get lots of stuff.”

Moore adds, “I think it will be a game changer, but the first rule of a manager is to maximize shareholder wealth, so the idea here is we want to make some money so our investors are repaid for their patience and the risk they’ve taken.”

Author: Katie Fletcher
Staff Writer, Biomass Magazine
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