How it Works
Advantages of the Flex Powerstation™
• Generates electricity from existing gas sources at landfills, anaerobic digester applications,
¯such as wastewater treatment plants or dairy farms, coal mines, industrial plants and oil fields
• Eliminates the need for gas compression and prior siloxane removal
• Runs equally well on 100% (1000 Btu/scf), 50% (500 Btu/scf), 15% (150 Btu/scf) and 5% (50 Btu/scf) methane fuel
• Operates cleanly and efficiently with a wide range of fuels including fuels with varying energy content
• Produces emissions (NOx, CO, VOCs) below 1ppm,
¯significantly lower than those from other power plants and flares
• Integrates two proven and mature technologies – gas turbine technology with thermal oxidation – in a
¯groundbreaking fashion
• Scales to match the available gas energy
The Flex Powerstation™
The Flex Powerstation™ is the integration of a gradual oxidizer and a FlexEnergy gas turbine, which results in a system that can generate electricity with near zero emissions from a wide range of gaseous fuels. The system accepts fuel gas with dilute methane concentration (5% methane) and aspirates this with air prior to oxidation. The Flex Powerstation™ tolerates both moisture and siloxanes in the fuel gas. The Flex Powerstation™ is the only complete clean energy solution that runs directly on low pressure, low flow and low energy content fuel gas.
In conventional technologies, compressed fuel is injected into compressed air and combusted to raise the temperature even further. This high-temperature and high pressure fuel/air mixture spins the turbine at high speeds to generate electricity. Each fuel is different, and therefore requires its own compressor, clean-up, and unique combustor. The siloxane removal and fuel conditioning system is the weakest link in traditional gas power plants. The fuel conditioning consumes up to 20% of the power generated. Such fuel conditioning and siloxanes removal are substantially eliminated with the Flex Powerstation™, as shown in Figure 1.
The Flex Powerstation’s™ fuel flexibility and low emissions enable the beneficial utilization of several types of weak fuels that no other power plant or gas-to-energy system can use. In the Flex Powerstation™, the conventional combustor is replaced by the gradual oxidizer. Fuel is aspirated with air forming a fuel/air mixture that is compressed and oxidized in a gradual oxidizer. The high temperature and pressure developed in the oxidizer is then used to spin the turbine and generate electricity. The Flex Powerstation™ does not require a fuel compressor and requires only a minimal fuel conditioning system.
The aspiration of fuel gases with atmospheric air (the lower shaded area in Figure 2) to achieve a uniform fuel/air gas mixture allows the Flex Powerstation™ to operate on a wide range of gaseous fuels. The Flex Powerstation™ operates in almost the same manner no matter what base fuel is used. Because there is no flame in the oxidizer, and the operating temperatures are kept below 2000° F (1100 °C), the Flex Powerstation™ avoids NOx formation.
The Flex Powerstation™ also provides a long residence time, allowing both CO and VOCs to be fully destroyed. The Flex Powerstation™ does not require siloxane removal or gas compression. Through the elimination of these problem-prone system components, the Flex Powerstation™ is inherently more reliable than conventional technology.
