Background to the Study

Nitrogen based fertiliser production is fundamental to meeting the growing food demand for the anticipated global population of 10 billion people by 2050.

The primary raw material for nitrogen production is natural gas but it can also be produced from coal, fuel oil and naphtha.  The technology for synthesizing ammonia, the feedstock for nitrogen fertiliser, is based on the 100-year-old Haber-Bosch process.  Approximately 65% of the natural gas utilised in Haber-Bosch process is needed as a source of hydrogen for ammonia and the remaining 35% is employed for heating the process itself. China currently accounts for 95% of global ammonia capacity based on coal feedstock.  In view of China’s ample coal reserves, coal gasification technologies are now used extensively.

This study investigated the life-cycle environmental footprint of nitrogen fertiliser production, with and without CO₂ capture, in four different regions: the United Kingdom; Norway; Saudi Arabia; and the United States.  The goal was to demonstrate how deep decarbonisation of fertiliser production could be achieved in each of these regions and compare the differences between them. 

Key messages

·    Fertiliser production is an important element in the global food production chain and is key to securing sustenance for the growing global population.  This is expected to increase to 10 billion by 2050 and consequently fertiliser production, which currently accounts for about 1.5% of global greenhouse gas emissions, will continue to be essential.

·        LCA (life cycle assessment) results from this study demonstrated a reduction of more than 30% in the environmental impact (as defined by the LCA) across each of the regions by integrating carbon capture technology (Scenario 2) compared to the case with no capture (Scenario 1).  Norway achieved a 70% reduction in the environmental impact against the benchmark scenario.

·        Steam Methane Reforming (SMR) is the most established hydrogen production technology and accounts for nearly 60% of the world’s hydrogen demand.  The second largest source for hydrogen currently is coal gasification at 19%. Approximately 30% of the global hydrogen produced (104 Mt) is utilised for ammonia production (the chemical precursor to nitrogen fertilisers).

·        Case 3, hybrid (natural gas/water electrolysis), showed the highest environmental impact unless the energy utilized for electrolysis was derived from non-fossil sources.  Norway was thus found to be the regional location that delivered the least impact in ammonia synthesis due to the country’s significant renewable energy electricity supply.

·        For Case 3, the study found that GHG emissions/tonne of urea and UAN (urea ammonium nitrate) were substantially higher for Saudi Arabia than for the other countries examined.  This was because:

            o   Virtually all the Kingdom's electricity is generated from natural gas, diesel oil, crude oil, and heavy fuel oil, with minimal contribution from renewable energy technologies.

            o   The study assumes the water used for electrolysis comes from desalination, which as well as being costly, is a very energy intensive process.

This report is available to download.