For more than a century, the world has relied on the Haber-Bosch and Ostwald processes to produce nitrogen fertilisers. Together, they form the industrial backbone of modern agriculture: first converting nitrogen from the air into ammonia and then converting ammonia into nitric acid and nitrate-based fertilisers. However, this essential industrial process has some major challenges.
Firstly, a major challenge is that the Haber-Bosch-Ostwald route is fundamentally built for scale. These plants are highly complex, capital-intensive facilities that only become economically attractive at very large capacities. This forces centralisation of production in industrial facilities.
Instead of producing fertiliser close to where it is used, the industry concentrates production in a limited number of global hubs, and then depends on long, vulnerable supply chains to move ammonia, nitric acid, and nitrate fertilisers to end users.
When energy prices spike, shipping becomes constrained, or geopolitics disrupt trade routes, fertiliser availability and affordability can change overnight. In many regions, access becomes the issue, not demand.
Another limitation is operational inflexibility. Traditional ammonia and nitric acid plants are designed for continuous, steady-state production. They are not naturally suited to frequent ramping or intermittent operation. This is a major mismatch with the future electricity system, where renewables are increasingly dominant and power availability can vary by hour, day, or season.
Fossil fuel dependency and significant Carbon dioxide (CO2) and Nitrous oxide (N2O) emissions from production are major challenges. The Haber-Bosch step requires hydrogen, and today that hydrogen is predominantly produced from natural gas through steam methane reforming, which generates large quantities of CO2.
Even where plants are highly efficient and well-controlled, the underlying chemistry and energy system remain carbon intensive. While conventional plants can be electrified in parts, the overall process remains rigid and difficult to adapt to variable renewable power without significant cost and engineering complexity.
Although this Haber-Bosch and Ostwald approach has delivered enormous volumes at low unit cost, it also comes with structural downsides that are becoming harder to ignore in a world shifting toward renewables, decentralised infrastructure, and lower emissions. These challenges are why new production routes are now gaining attention, particularly those that can use renewable electricity directly and avoid fossil feedstocks entirely.