Investigation and optimization of a new hybrid natural gas reforming system for cascaded hydrogen, ammonia and methanol synthesis

A new configuration to convert the traditional ammonia synthesis plants into an environmentally benign process is proposed in this study. The proposed design is implemented by integrating three different types of natural gas reforming for clean hydrogen, methanol and ammonia synthesis. The solar heat source provides the absorption cooling unit with heat and natural gas reformers with steam. The CO₂ emissions released by the natural gas reforming configuration reacts with hydrogen for methanol synthesis. A pressure swing adsorption unit separates oxygen for natural gas autothermal reforming and nitrogen for ammonia synthesis. A part of hydrogen produced by the natural gas reforming unit is designed to pass through a double-stage ammonia production reactor for ammonia synthesis. The proposed configuration yields 10 mol/s of H₂ and 2.4 mol/s of NH₃. The overall system energetic and exergetic efficiencies are found to be 66.83% and 68.55%. The present system yields 13.31 mol/s of CH₃OH and 625.9 kW of cooling. Moreover, numerous sensitivity analyses are conducted on the proposed configuration and its performance assessment.