Recent advances and intensifications in Haber-Bosch ammonia synthesis process

• Recent developments in process intensification for the Haber-Bosch process are discussed. • Maintaining its lead in ammonia synthesis, the Haber-Bosch process requires evolution into a less energy-demanding format for decentralized production. • Multifunctional and membrane reactors innovate towards smaller, more efficient systems. • Shifts towards low-temperature, low-pressure synthesis fed with water electrolysis could eliminate the main compressor. • Supported metal halides as a viable alternative for energy-efficient ammonia separation. Ammonia is crucial as it serves as a key nitrogen source in fertilizer production to enhance crop growth and as an emerging energy carrier due to its high hydrogen content and ease of liquefaction. Despite various technological changes proposed and implemented since its inception, the Haber-Bosch process remains the predominant method for ammonia production. We first give a bird's eye view of current ammonia synthesis technologies available based on the latest trends, to justify why we think the conventional Haber-Bosch process is still a relevant technology worth investigation for further improvement. We review the engineering design modifications within the ammonia synthesis loop, examining improvements in the efficiency of ammonia synthesis. This review gives an overview of recent research and advancements focused on process intensification within the loop and its individual key components, i.e., the reactor and the catalyst, separation, and purge gas recovery technologies. It highlights significant progress and explores potential future directions in these areas.