Evaluation of a Low Emission Gas Turbine Operated on Hydrogen

Abstract

The ever increasing strain on traditional centralized power generation and distribution systems has led to an increase in the use of distributed generation (DG) technologies. DG technologies are commonly found in urban areas that are sensitive to criteria pollutants, and as a result, they are subject to increasingly stringent emission regulations. Paralleling the growth of installed DG is the ever-increasing interest in hydrogen as an alternative fuel to natural gas. As a hydrogen infrastructure is developed, a desire to use this new fuel for DG applications will evolve. Microturbine generators (MTGs) are one example of DG technology that has emerged in this paradigm and are the technology of interest in the present work. To evaluate the potential role for hydrogen fired MTGs in this paradigm, understanding of what emission levels can be expected from such a system is needed The current study retrofits a natural gas fired MTG for operation on hydrogen and characterizes the resulting operability and emissions performance. The results of implementing design changes to improve emissions performance while maintaining stability and safety of the MTG when operating on hydrogen fuel are presented. The results also show improved stability limits which are utilized to help attain lower emissions of NOx. Further optimization is needed to achieve the NOx levels necessary to meet current regulations.

Analysis of NOx Formation in a Hydrogen-Fueled Gas Turbine Engine

“…The utilization of pure hydrogen in a gas turbine poses certain challenges that have been outlined. 6,7 The nature of hydrogen to react easily and quickly have led to concern of flashback and autoignition for premixed systems. In addition hydrogen reacts on average 126K hotter than natural gas for an equal equivalence ratio.…”

“…In addition hydrogen reacts on average 126K hotter than natural gas for an equal equivalence ratio. 7 Emissions of NO x from a stoichiometric hydrogen reaction have been shown to exceed current regulatory limits. 6 Measurements of NO have been reported for a retrofitted natural gas MTG operated on hydrogen.…”

Investigation of a pure hydrogen fueled gas turbine burner

“…The injection system is modified to be co-flow, and it is inspired by Therkelsen [34]. Its design philosophy is the preventing the high turbulence regions, typical of the cross-flow, which brings to the flashback.…”

Micro-Mixing Lean-Premix System for Ultra-Low Emission Hydrogen/Syngas Combustion

“…Further details about the operation of the GC are found in previous work. 4 Similarly, a high range flame ionization detector (FID) was used to measure natural gas concentrations at the injector exit plane. It was also zeroed and spanned prior to and after the tests.…”