The most efficient and sustainable process to produce nitrogen-based fertilizers using renewable resources and reducing greenhouse gas emissions is the Haber-Bosch process combined with renewable energy sources and carbon capture technologies.The Haber-Bosch process is the primary method for producing ammonia NH3 , which is the main component of nitrogen-based fertilizers. This process combines nitrogen N2 from the air with hydrogen H2 to produce ammonia. The hydrogen is typically obtained from natural gas, which contributes to greenhouse gas emissions.To make this process more sustainable and reduce greenhouse gas emissions, the following modifications can be made:1. Renewable hydrogen production: Instead of using natural gas, hydrogen can be produced using renewable energy sources like solar, wind, or hydroelectric power. Electrolysis of water H2O using renewable electricity can generate hydrogen without any greenhouse gas emissions. This hydrogen can then be used in the Haber-Bosch process to produce ammonia.2. Carbon capture and storage CCS : If natural gas is still used as a hydrogen source, carbon capture and storage technologies can be implemented to capture CO2 emissions during the process. The captured CO2 can then be stored underground or used in other industrial applications, reducing the overall greenhouse gas emissions.3. Nitrogen fixation using renewable energy: Another approach is to develop alternative methods for nitrogen fixation that utilize renewable energy sources. For example, some researchers are exploring the use of bioelectrochemical systems, where microorganisms can convert nitrogen gas into ammonia using electricity generated from renewable sources.4. Precision agriculture: To minimize the environmental impact of nitrogen-based fertilizers, precision agriculture techniques can be employed. These techniques involve using advanced technologies like GPS, sensors, and data analytics to optimize fertilizer application, ensuring that the right amount of nutrients is applied at the right time and place. This reduces the overall amount of fertilizer needed and minimizes the release of greenhouse gases from excess nitrogen.By combining these strategies, the production of nitrogen-based fertilizers can become more efficient and sustainable, reducing greenhouse gas emissions and utilizing renewable resources.