Session: 04-30 Emissions - hydrogen/ammonia III

Paper Number: 121302

121302 - Micro Gas Turbine Fed With Ammonia As Fuel: Performance Analysis and NOx Emissions Reduction 

The increasing global demand for energy and the need to reduce polluting emissions necessitate the use of alternative fuels, especially in the hard-to-abate sectors, that are more attractive from an environmental standpoint and reduce the production of harmful compounds like sulfur oxides, nitrogen oxides, carbon monoxide, and greenhouse gases like carbon dioxide. Considering ammonia as the carrier of green hydrogen and as a renewable carbon-free fuel, it is anticipated to play a fundamental role in the decarbonization of the energy supply chain. In this study, a simulation algorithm has been used to evaluate the performance of a 3.2 KWe Micro Gas Turbine (MGT) fed by ammonia. The algorithm comprises a set of equations describing the behavior of the turbomachines,  the combustor, the heat exchangers, the pressure losses in each component, and the consumption of the other auxiliary devices. To examine the combustion kinetics and evaluate the MGT emissions with ammonia feed, a further algorithm utilizing Cantera’s library has been developed. This model is a mono-dimensional tool that allows us to assess the mixing flows, the temperature trends, and the formation of the combustion products. Results indicate that, if a suitable fuel injection and an air supply method are used, the electric power output obtained using Ammonia (NH3) with a Lower Heating Value (LHV) of around 18.6 MJ/kg turns out to be comparable to that obtained with Methane (CH4), while the electric efficiency is marginally lower (5.16%). In this work, due to the high amount of NOx emission, the Rich-Lean non-premixed strategy for combustion is investigated for NOx reduction in a three-stage combustion chamber. By adopting this strategy, the amount of NOx pollutant has been reduced to 744 ppm (15% O2), about 92% less than previous strategy. The benefit of zero CO and CO2 emissions can be achieved if compressor–turbine matching is adjusted to compensate for the fuel reduction calorific value: at rated power, when the most enormous fuel input is required, flow rates of air decreased by 1.13%, and fuel mass flow rates increased by 159% compared to methane.

Presenting Author: Mohsen Fatehi Free university of Bolzano

Presenting Author Biography: Mohsen Fatehi is a Ph.D. student of Sustainable Energy and Technologies at the Free University of Bolzano. He received his Master's Degree in Mechanical Engineering (Energy Conversion) from Isfahan University of Technology. He has more than ten years of experience in the field of turbomachinery devices, especially gas turbines.

Authors:

Mohsen Fatehi Free university of Bolzano
Graziano Campaldini Free University of Bolzano
Massimiliano Renzi Free University of Bolzano