EnerTech’s patented SlurryCarb™ process chemically converts Biosolids into a highenergy solid fuel, providing an environmentally and economically sound solution for biosolids disposal. The proven technology produces significant savings in both operating and capital costs, and commercial installations of the process are currently under development.
Simplicity of operation is key to the SlurryCarb™ technology. Biosolids at up to 30% solids content are brought to a central manufacturing facility where they are processed as a pumpable slurry, creating savings in capital and operating costs. The Biosolids slurry is continuously pumped and pressurized above its saturated steam pressure to maintain a liquid state throughout processing. By avoiding evaporation, thermal energy inputs for the evaporation of water are minimized. The SlurryCarb™ process requires approximately 65% less energy than traditional drying methods.
Upon reaching the desired reaction pressure and temperature, the molecular structure of the Biosolids is reconfigured. The cellular structure of the Biosolids ruptures and carbon dioxide gas splits off from the solid waste, a step called “carbonization.” This reaction significantly reduces the size and improves the uniformity of the Biosolids molecules. The reacted product becomes extremely hydrophobic and can be dewatered to greater than 50% solids. This dewatered, reacted product is concentrated in carbon, and over 80% of the original water present in the Biosolids is removed without evaporation. The reacted, dewatered product is pelletized to form a fuel that burns at up to 18,607 kJ/kg (8000 Btu/lb). This fuel, called E-Fuel, is exported to a customer and utilized as a renewable fuel. The filtrate from dewatering is pretreated to the standards of the local wastewater treatment plant.
In addition to the energy savings, the SlurryCarb™ process removes key pollutants, such as chlorine, from the E-Fuel. Emissions from the combustion of E-Fuel exceed emissions standards without extensive air pollution control systems. And, as a renewable fuel, E-Fuel produces essentially zero net greenhouse gas emissions. The SlurryCarb™ process eliminates the release of methane encountered by landfillig Biosolids. The release of methane from landfills is a major source of man-made greenhouse gases.
EnerTech successfully demonstrated its technology on a commercial scale with the construction and three-year operation of a 20 ton per day plant in Japan. EnerTech also constructed a Process Development Unit (PDU) located in Atlanta. EnerTech’s 54.5 l/h (14.4 GPH) PDU was designed to procure engineering data from extended operations. The PDU includes all the necessary pumping, heating, depressurizing and dewatering systems necessary to simulate a commercial scale SlurryCarb™ facility.
By avoiding the evaporation of water, the economics for the SlurryCarb technology are extremely competitive with current methods employed by the industry. With operating experience from the Japanese plant and significant research conducted at the PDU, EnerTech and its engineering partners have designed the 125 dry tons per day facility in the Los Angeles area. The permit cycle is underway, the development team has been determined, and users for the fuel established. Significant progress has been made on the Los Angeles Area Project over the past few months. This paper will include an update on the status of the Los Angeles Area Project.
The need for environmentally and economically sound alternatives to traditional Biosolids disposal methods is becoming increasingly evident. EnerTech’s ability to offer the municipal market and large private waste producers a low-cost, sustainable, and environmentally-friendly solution that overcomes regulatory hurdles has already gained the company widespread interest and support for its SlurryCarb™ process.
KEY WORDS Energy Production, Renewable Fuel, SlurryCarb™
