Blending hydrogen process gas with natural gas

GE has introduced flexible fuel-blending technology for its Frame 7FA gas turbines that enables turbine operators to lower their fuel costs and overall operating expenses by reducing the amount of natural gas fuel required by the turbines, while also offering a more efficient use of process gases.

The first application of this new system is four GE Frame 7FA Gas Turbines at Dow Chemical Company’s Plaquemine, La., facility.

This new technology enables the blending of up to five percent hydrogen into a GE dry low NOx (DLN) 2.6 combustion system. This enables customers to use hydrogen gas that is a byproduct of a petrochemical process as part of the fuel mix for a 7FA Gas Turbine. The new product joins GE’s portfolio of service offerings designed to help customers meet today’s challenges by helping to operate their power plants cleaner, smarter and more efficiently.

The GE fuel-blending system includes hardware required for mixing the gases, instrumentation for measuring the gas compositions and controls to maintain the proper fuel flow into the gas turbine. No physical changes were made to the gas turbine compressor or hot gas path. The validation of this technology has demonstrated that the Frame 7FA Gas Turbine combustor can accommodate variations in fuel composition and meet all operability, emissions and performance needs.

To date, three of the four units are operating on blended fuel, with the fourth unit to operate on blended fuel later this summer. To date, these units have accumulated more than 5,100 hours on blended fuel.

GE’s fuel-blending system for the 7FA allows the use of process or waste gases in a high-efficiency power generation platform instead of having to use the process gas in a lower efficiency system, such as a duct burner. It also can reduce the need to dispose of the process gas by flaring.

The new hydrogen fuel-blending system has been initially designed for use with GE’s advanced 7FA Gas Turbine, part of GE’s worldwide fleet of F-class gas turbines, which has compiled more than 35 million hours of service.