Throughout the world, natural gas is transported long distances in pipelines under high pressure needed to maintain a high volume of flow in the pipeline network. However, before distributing gas to homes and businesses, the pressure must be reduced, which is undertaken at letdown stations, typically located on the edges of population centers, and as the pressure is reduced, the gas cools as it expands. To prevent the gas systems and pipeline from freezing, the letdown stations use a gas-fired burner to generate heat. This standard practice fails to harness the energy lost from this pressure reduction process and the combustion-based boiler that produces the needed heat emits pollutants and carbon.
FuelCell Energy’s SureSource Recovery systems are located at natural gas letdown stations to generate ultra-clean power and heat and to utilize, what is in essence, ‘free’ energy from the pressure-reduction process to generate additional zero- emissions power, all in a highly efficient manner. The SureSource Recovery solution is comprised of a SureSource fuel cell plant and a turbo-expander. The turbo–expander electricity production is based on the amount of gas flow through the pressure-reduction station, and requires a supply of heat to prevent overcooling the pressure reduced gas. The fuel cell, configured for combined heat and power (CHP), provides the heat, which is usually produced from gas-fired boilers, improving the station’s carbon footprint and reducing emissions.
The combination provides a unique, electric power generator, combining baseload and variable power output. The solution operates in parallel with the existing letdown station and offers the utility station operator the ability to add a clean grid power resource at the station, while improving the efficiency of the natural gas delivery system.