The most effective process for producing ammonium nitrate fertilizer from nitrogen gas and ammonia gas is the Haber-Bosch process, followed by the Ostwald process.1. Haber-Bosch process: This process involves the synthesis of ammonia NH3 from nitrogen gas N2 and hydrogen gas H2 . The optimal operating conditions for the Haber-Bosch process are:- Temperature: 400-500C 752-932F - Pressure: 200-300 atm 20-30 MPa - Catalyst: Iron-based catalysts, typically with potassium oxide or aluminum oxide as promoters2. Ostwald process: After obtaining ammonia through the Haber-Bosch process, the Ostwald process is used to convert ammonia into nitric acid HNO3 . The optimal operating conditions for the Ostwald process are:- Temperature: 800-900C 1472-1652F for the initial oxidation of ammonia, followed by cooling to 30-40C 86-104F for the absorption of nitrogen dioxide NO2 in water- Pressure: Atmospheric pressure- Catalyst: Platinum or platinum-rhodium gauzeFinally, ammonium nitrate NH4NO3 is produced by combining ammonia NH3 and nitric acid HNO3 in a neutralization reaction:NH3 + HNO3 NH4NO3Ammonium nitrate is then used as a fertilizer due to its high nitrogen content, which is essential for plant growth.