Experimental Study of the Pyrolysis of NH₃ under Flow Reactor Conditions

Area of Science:

• Chemical Engineering
• Combustion Science
• Energy Transition

Background:

• Ammonia (NH3) is a potential low-carbon fuel and energy carrier.
• Understanding NH3 conversion, especially under pyrolysis conditions, is crucial for its combustion.
• Pyrolysis data informs the development of NH3 combustion mechanisms.

Purpose of the Study:

• To experimentally investigate ammonia pyrolysis.
• To determine the influence of reactor material, bath gas, concentration, and residence time on NH3 conversion.
• To provide data for NH3 combustion mechanism development.

Main Methods:

• Ammonia pyrolysis experiments were conducted in quartz and alumina tubular flow reactors.
• Temperatures ranged from 900 to 1800 K, using Argon or Nitrogen as bath gas.
• Product analysis was performed using gas chromatography and infrared spectroscopy.

Main Results:

• Hydrogen (H2) and Nitrogen (N2) were identified as the primary products of ammonia thermal decomposition.
• Reactor material (quartz vs. alumina) showed no significant difference in NH3 conversion below 1400 K.
• NH3 conversion increased with gas residence time, narrowing the effective temperature window.

Conclusions:

• Ammonia pyrolysis is primarily driven by temperature and residence time.
• Reactor material and gas composition have minimal impact on NH3 conversion under studied conditions.
• Findings contribute to a better understanding of ammonia as a fuel for a low-carbon economy.