Minergy Corp. has developed and commercialized several vitrification technologies for the recycling of such high volume wastes as municipal biosolids, industrial sludges, and contaminated sediment and soils. These technologies perform mineral recovery from the waste material, converting them into construction material and industrial feed stocks which are inert, marketable products. With a continuously operating processing system installed at the waste source, vitrification provides a sustainable management alternative by reducing handling, eliminating downstream liabilities, reducing or eliminating disposal costs, and, in the right situations, can offset other energy demands.
The Glass Aggregate Technology is a mineral recovery process that melts the mineral content of sludge, using a high temperature furnace. Glass Aggregate Technology is Minergy’s initial vitrification technology and has been in commercial operation since 1998 at the Fox Valley Energy Center, previously Minergy’s Fox Valley Glass Aggregate Plant (FVGAP). At the heart of the technology are two (2) 7-foot-diameter cyclone furnaces in which sludge is co-fired with auxiliary fuel (coal or natural gas) and ambient air. The technology features two significant modifications to the standard cyclone furnace design:
- Introduction of fuel into the cyclone using four (4) tangential secant ports on each cyclone.
- The lower furnace of the steam generator is specially designed to maintain high temperatures to allow the molten slag to run down the lower furnace walls and through the discharge opening in the lower furnace floor.
Minergy’s oxygen-enhanced GlassPack® closed-loop combustion system was developed in response to strong customer interest in the Glass Aggregate Technology process and a desire to vitrify municipal biosolids (wastewater treatment sludge) and other high-volume wastes. The primary objective of GlassPack® is to provide a scaled-down version of the Glass Aggregate Technology that can be integrated into the waste source’s facility operation. In addition GlassPack®:
- Eliminates the need for co-fire fuel to achieve vitrification
- Provides significant environmental air emissions improvement over current combustion technologies
- Puts forward a compact and modular design that minimizes capital cost by maximizing the use of lower-cost shop fabrication
Minergy’s Glass Furnace Technology was developed specifically to treat contaminated sediment and soils. Whereas both the Glass Aggregate Technology and GlassPack® use the heat energy released from the sludge to achieve vitrification, the Glass Furnace Technology uses oxygen and natural gas (oxy-fuel) burners to vitrify (melt) the inorganic fraction of sediment and soils into a glass aggregate. An ancillary benefit to subjecting the contaminated sediment and soil to the >2,300 degrees Fahrenheit necessary to melt the material is that organic contaminants such as PCBs, dioxin/furans and polycyclic aromatic hydrocarbons (PAH) are effectively destroyed.
Minergy Lightweight Aggregate (LWA)™ is a patented pelletized mixture of fly ash, wastewater treatment solids, paper mill sludge and clay binders that is fired in a rotary kiln, converting it into a durable, ceramic-like lightweight aggregate. The Minergy LWA™ process ensures strict quality control measures, providing consistency and highly dependable performance. Unlike conventional lightweight aggregate manufacturing processes that rely on a large amount of energy to power the process, the ash and sludge provided fuel for most of the plant’s energy needs – minimizing the need to consume other fossil fuels.