Effects of Hydrogen Fueling on NOx Emissions: A Reactor Model Approach for an Industrial Gas Turbine Combustor

Abstract

Addition of hydrogen (H2) to gas turbine fuel has recently become a topic of interest facing the global challenges of CO2 free combustion. As a drawback, Nitrogen oxide (NOx) emissions are likely to increase in hydrogen-rich fuel combustion which in return limits the use of the technology. In the course of this development, a model-based quantification of NOx emission increase by fuel flexibility may identify possible operation ranges of this technology. This paper evaluates the effect of an increased hydrogen fraction in the fuel on the NOx emissions of a non-premixed 10 MWth gas turbine combustor. A simple reactor network model has been set up using a perfectly stirred reactor (PSR) to simulate the flame zone and a plug flow reactor (PFR) to simulate the post flame zone. The change of residence time in the flame zone is accounted for by an empirical expression. The model is validated against data from high-pressure test rig experiments of an industrial non-premixed gas turbine combustor. The model results are in good agreement with the experimental data. Based on the model results, a fundamental correlation of the effect of hydrogen on the NOx emissions is formulated.

Hydrogen Blending into Natural Gas Pipeline Infrastructure: Review of the State of Technology

“…Lean premixed systems are heavily optimized in terms of equipment design and control, which lends to limitations in fuel flexibility. Hydrogen impacts both diffusion and lean premixed flame combustion system technologies differently in terms of NO x emissions and fuel compatibility (Kroniger, Lipperheide, and Wirsum 2017;Mohammad et al 2020;Abbott, Bowers, and James 2012).…”

“…NO x emissions are primarily influenced by combustion temperature, which could be impacted by a fuel's hydrogen composition. Without an emissions control technology, diffusion combustion systems are poorly suited for hydrogen-blended natural gas fuels because the presence of hydrogen increases turbine combustion temperatures, which in turn increases NO x emissions exponentially (Kroniger, Lipperheide, and Wirsum 2017). NO x emissions may also increase for lean premixed flame combustion systems using natural gas fuels with increasing hydrogen composition.…”

Optimal Operation of a Gas Turbine Cogeneration Unit With Energy Storage for Wind Power System Integration

“…In order to overcome these challenges, the topic of hydrogen combustion in gas turbines is the focus of various ongoing research activities (e.g. [13]). Today, commercially available gas turbines allow hydrogen contents up to 45 vol.…”