From left to right (L-R): Kristin Smith, editor of Renewable Energy from Waste magazine, acting as moderator; Jim Bohlig of Repower South, Nathan Rich of Wasatch Integrated, Jim Wollshlager of Organix Solutions; and Fanis Tsilionis of Helector S.A.
Across the globe, keeping up with fuel processing can be a challenge. In the session “Fuel Processing Innovations” at the Renewable Energy from Waste Conference in Long Beach, California, Nov. 15, guest speakers shared their innovations and its effects.
“[Renewable energy] has to be a complementary solution,” Jim Bohlig, chief development officer of Repower South Spartanburg, South Carolina, said during the panel. “Solid waste is a personal matter that moves passed landfilling and toward diversion and recovery.”
Repower South offers its ReEngineered Feedstock, a biogenic alternative fuel source called “qualified biomass” derived from waste. It is produced through an U.S. Environmental Protect Agency (EPA)-approved process that results in GHG emissions two times smaller than biomass.
The fuel is composed of nonrecyclable fiber and polymer components of municipal solid waste (MSW) after front end processing in a materials recovery facility (MRF). It uses the same equipment and process that creates wood and other fuel pellets.
It has a heating value of more than 10,000 British thermal units (Btu) per pound, higher than the 6,000 British thermal units per pound from traditional biomass. The fuel has a 1,563 pounds of carbon dioxide per megawatt hour emission rate, which Bohlig says is lower than both traditional biomass and coal.
An example of a current application for this qualified biomass is in Chesapeake, Virignia, Bohlig said. A 15-year MSW supply agreement is in place between Southeastern Public Service Authority and Repower South, with a 10-year option. The process allows more than 95 percent of recoverable recyclables to be recovered, and 40 to 50 percent of the MSW is used as feedstock for fuel production. As a result, Bohlig said, 60 to 70 percent of the waste is diverted from landfill.
Nathan Rich, executive director of Layton, Utah-based Wasatch Integrated Waste Management District, worked with the Davis Energy Recovery Facility to upgrade its fuel processing system.
The Davis Energy Recovery Facility is located in a special service district and is owned by Davis and Morgan counties, as well as 15 cities in Utah that produce 275,000 of MSW annually.
In 2014, the facility used 11,538 tons of its annual 274,325 tonnage for energy recovery. Wasatch Integrated implemented mixed waste preprocessing to improve fuel quality for the facility. Renewable Resource Consultants own and engineer the preprocessing facility while Machinex provided $1.57 million worth of equipment. Jacbonsen Construction was used for the site and building work at a cost of $1.72 million. The total project cost was $4 million.
Originally, yard waste in particular was an issue for the facility, hurting its combustion process the most. Its preprocessing system first removes materials that can’t be processed, recovers limited recyclables, opens bags and break glass, then removes everything smaller than two inches from the waste—including yard waste, glass, organics and dirt.
With the preprocessing system in place, the facility uses less natural gas, decreased hydrated lime usage by 30 to 50 percent, decreased its carbon dioxide and sulfur dioxide emissions and recovered more ferrous scrap from its bottom ash.
Organix Solutions, Maple Grove, Minnesota, has a “layered” approach to waste management and energy recovery, according to CEO Jim Wollshlager.
In order to successfully achieve the first layer (“source separated organics”) of Organix’s process, the company started the Green Bag Organix co-collection program for municipalities and haulers, where organic waste is co-collected in a separate bag with other MSW where it is sorted and diverted. More than 31 cities throughout Minnesota are participating in the program.
For processing at the MRF (layer two), Wollshlager said 20 to 30 percent of the waste stream is captured in a 40-inch long trommel screen. Around 56 percent of the materials captured is organic materials. The other 42 percent of materials is then captured in the BurCell system (layer three), and a Torxx Kentic pulverizer prepares the feedstock for anaerobic digestion (layer four). This produces 320,000 diesel gallon equivalents of CNG for Organix.
In Greece, Fanis Tsilionis, senior engineer at Helector S.A., headquarted in Nea Kifissa, Greece, worked on a refuse derived fuel (RDF) project in the Sofia municipality. The project held a trial operation for 12 months, from October 2015 until September 2016, where the input was composed of a high number of organics, paper, plastics and glass.
The MSW is unloaded into two deep bunkers and four process lines. The glass and ferrous metals are recovered, and the material is mechanically separated for bio-drying and composting. This separation recovers plastics and paper for reuse. Twenty-six bioreactors dry the material and three process lines transfer it to the RDF production building.
During RDF production, combustible materials, PVC and organics are removed and the remaining material is baled. The RDF then is sent to cement kilns, used at the Sofia municipality’s combined heat and power plant and has the potential to be used at a waste-to-energy facility.
The Renewable Energy from Waste Conference took place at the Westin Long Beach, Long Beach, California, Nov. 14-16.