Numerical study assessing various ammonia/methane reaction models for use under gas turbine conditions

Abstract

Ammonia as an alternative fuel and hydrogen carrier has received increased attention in recent years. To explore the potential of co-firing ammonia with methane for power generation, studies involving robust mathematical analyses is required to progress towards industrial implementation. To explore the chemical kinetic mechanisms best suited to ammonia/methane combustion in gas turbines, five different detailed mechanisms are compared to assess their efficacy in representing the reaction kinetics under practical gas turbine combustor operating conditions. Ignition delay time is compared with recently published predictions showing that the mechanisms of Tian and Teresa exhibit the best accuracy over a large range of conditions. A one-dimensional simulation was also conducted using a Chemical Reactor Network (CRN) model, thus providing a relatively quick estimation of the combustion mechanisms under swirling combustion conditions. The simulation of NOx emissions indicate that the Tian mechanism performs better than the others considered. Hence, the Tian mechanism was selected as the most appropriate for further studies of ammonia/methane combustion through a set of experiments carried out at various equivalence ratios and pressure conditions. Finally, sensitivity and pathway analyses were also performed to identify important reactions and species under high-pressure conditions, areas that need more attention for model development and emission control in future studies.

Experimental and modeling study on ignition delay of ammonia/methane fuels

“…It has been tested in extensive combustion studies on ammonia, 37,38 showing good accuracy in simulation modeling work. Among the different widely used ammonia combustion chemical mechanisms, the Tian mechanism was found to have the best performance especially for ignition delay time calculation in previous numerical studies 39 . Therefore, in this study, the Tian mechanism is chosen to perform numerical investigation on the ignition of ammonia/methane fuels over an extensive range of conditions.…”

Study on counterflow premixed flames using high concentration ammonia mixed with methane

“…A number of studies have explored utilizing ammonia in combustion equipment such as internal combustion engines, gas turbines, boilers, etc [7][8][9][10][11][12][13][14]. For instance, Ryu et al [8] developed direct injection strategies of gaseous ammonia in SI engine and proved feasible engine combustion and energy efficiency.…”

Computation of partial molar properties using continuous fractional component Monte Carlo

“…the Haber-Bosch process for ammonia production [44]. The reason to select this mixture as a realistic case study is that ammonia is a useful chemical commodity and has received lots of attention both in academia and industry [45][46][47][48][49][50][51]. It is also a promising alternative medium for energy storage and transportation [52][53][54][55].…”