The heart of a Novo waste-to-energy facility is the patented Aireal® Combustion System. The Aireal® Combustion System represents the latest development for combustion systems in the industry. This state-of-the-art mass burn design does not require any fuel preparation and has no moving parts exposed to the combustion zone. Fuel (municipal solid waste or other biomass) is agitated and moved through the combustion zone via a patented pneumatic process. The Aireal® system is typically designed and fabricated in standard size modules.
Each module is shop fabricated and delivered to the facility site for final assembly. The Aireal system has very high combustion efficiencies, very low CO and NOx, emissions and results in the lowest capital, operating and maintenance costs. It will also meet the most stringent emission standards currently proposed for municipal waste combustors. For waste-to-energy applications, waste volumes are typically reduced by 90% through the combustion process.
Combustion efficiency is measured by how much of the heat available in the fuel is released and utilized. Primary indicators of good combustion efficiency are low unburned carbon in the ash, and low emissions of combustion related pollutants, primarily carbon monoxide.
The Aireal Combustion System has achieved excellent carbon burnout in the commercial operating facilities. Recent tests on MSW combustion ash demonstrated unturned carbon levels in the 1-2 percent range.
High levels of carbon monoxide (CO) in the flue gas is a sign of poor combustion efficiency. The EPA sets a limit of 100 parts per million (ppm) CO in the combustion gases for these types of facilities. The Aireal technology has consistently exhibited CO emissions averaging between 15 and 40 ppm. Nitrogen Oxide (NOx) emissions are generally 50-60 percent lower than other combustion technologies without NOx control.
Novo air pollution control (APC) systems typically consist of a dry sorbent injection system with a fabric filter (DSI/FF). Dry sorbent is injected into the cooler combustion gases leaving the boiler economizer. The sorbent (typically hydrated lime) provides for the removal of a large portion of the acid gases (SO2 and HCl). Powdered activated carbon (PAC) is also injected at this point to remove heavy metals and dioxins/furans. The gases then pass through a fabric filter, which removes in excess of 99.99 percent of all particulates. The clean gas exiting the fabric filter is discharged to the stack, where the gases are then emitted at an elevated point in the atmosphere. Fly ash collected in the boiler and fabric filter hoppers is transported by conveyor to the main ash discharge conveyor.
Novo Energy's air pollution control systems have realized superior results.
Waste-to-Energy facilities produce steam as a result of the heat from the combustion process heating a boiler. This steam can be used for turbine generators to produce electricity, or it can be sold as steam to local industry, schools, hospitals or cities for process use heating and cooling. Novo projects are generally engineered to produce electricity that can be used internally or sold back to the national power grid. We maximize electric generating capacity and steam production capacity on a project-by-project basis depending on local electricity rates and steam needs. Appropriate equipment will be installed to maximize efficiency based on those rates and the overall return on investment for the project.
A core market focus of Novo in the renewable energy marketplace is waste to energy (WTE) projects that utilize municipal solid waste (MSW) as the principal fuel source and recover the energy for sale in the form of steam and/or electricity. WTE projects are classified as renewable energy sources and are better environmental alternatives for the following reasons:
- Reduced CO2 Emissions - The majority of MSW is comprised of biomass material; that is material that originated from a biological life source including trees or plants. The U.S. EPA estimates that approximately 70 percent of typical MSW composition in the U.S. is biomass. Plant and trees consume carbon dioxide (CO2) during their growth and the principal emission from combustion of these materials in a WTE project is CO2. As a result, WTE projects are “net zero” CO2 sources to the environment from the combustion of the biomass portion of the fuel stream.
- Reduced Methane and Fossil Fuel Emissions – WTE projects reduce the amount of waste going to landfills by approximately 90-95 percent on a volume reduction basis. When landfilled, the primary emission from the anaerobic digestion of the MSW is methane, which is estimated to be 21 times more reactive than CO2 from a greenhouse gas standpoint. Additionally, WTE facilities often offset energy production from fossil fuel based facilities. Therefore, efficient combustion of MSW is far better with respect to greenhouse gas emissions than landfilling.
- Renewing Fuel Stream – MSW is a fuel source that has steadily grown throughout the history of the United States and other developed countries. The U.S. presently generates approximately 225 million tons of MSW on an annual basis. Only 15 percent of the MSW in the U.S. is presently utilized as fuel, compared to roughly 50 percent in Europe.
The Novo Technology Package can be scaled to accommodate as little as 100 tons/day of municipal solid waste to as high as 1,200 tons/day based upon the available waste for processing and disposal. Multiple combustion, boiler and air pollution control system trains can be added for redundancy and increased processing capacity.