Decarbonisation of fertiliser sector: Indias 2070 net zero road map

Our objective of achieving net-zero emission by 2070 requires action on all fronts viz. industry, agriculture, transport, and energy sectors. Many public and private enterprises have drawn action plans for decarbonisation of their respective activities with the ultimate objective of net emission. The Government of India has also been active on the policy front to facilitate and accelerate the progress towards higher efficiency levels using the best available technologies and use of green energy. Production and use of green hydrogen is also a focus area, and the action plan has been formulated and is being implemented under the ‘Green Hydrogen Mission’.Sectors like steel, cement, and fertilisers are considered hard to abate sectors. There are technological and other challenges in greening these sectors. But significant progress can be made even with the available technologies. Let us examine what can be realistically achieved in both short and medium term specifically in the fertiliser sector.Intensive agriculture with a high level of productivity requires the application of plant nutrients. Chemical fertilisers provide these nutrients in highly concentrated form. The use of chemical fertilisers will continue to be required to realise high yields of various crops year after year. Other sources of nutrients like organic manure and bio-fertilisers will no doubt play an extremely important role in maintaining or restoring soil health. But these will act as supplements to chemical fertilisers to meet the requirement of a high level of plant nutrients.Production of fertilisers is highly energy-intensive, requiring the use of fossil

fuels. Production of all nitrogen-containing fertilisers requires the use of ammonia as one of the essential inputs. Production of ammonia consumes almost 80% of the total energy spent in the production of fertiliser products. Therefore, there is always a focus on achieving high energy efficiency in the production of ammonia. Indian ammonia plants have kept pace with the technological developments and have continuously improved energy efficiency. Investment in energy efficiency projects has been mainly driven by the fertiliser pricing policies in vogue from time to time. The average energy consumption of Indian ammonia plants is better than the average of world plants as per the data available from the International Fertilizer Association and Fertiliser Association of India.In spite of large efficiency improvements achieved by the Indian fertiliser industry, there have to be new initiatives to move towards net-zero emission. Production of ammonia requires the production of hydrogen from fossil fuels, which is mainly natural gas. In fact, the fertiliser sector is one of the two major industrial sectors, the other being refineries, using hydrogen. This hydrogen can be produced through electrolysis of water using renewable energy. This technology has been used over the years. There was an ammonia plant at NFL, Nangal, where green hydrogen was produced using hydropower in the 1960s and 70s. The electrolysis technologies since then have become more efficient, and there are further developments on the horizon, which will bring down the cost of equipment (electrolysers) and consumption of energy per unit of hydrogen.India is likely to produce about

19 million tonnes of ammonia in 2023-24, and another 2.5 million tonnes will be imported. Given the present level of energy efficiencies, production of 21.5 million tonnes of ammonia will result in 43 million tonnes of carbon dioxide emission per year. The reduction in carbon dioxide emission can be achieved by further improving the efficiency of existing plants and substitution of grey ammonia (produced from fossil fuels) with green ammonia (produced using renewable energy). There is scope to improve the energy efficiency of existing ammonia plants and reduce natural gas consumption by 7-8 per cent by 2030. This will likely save carbon dioxide emission of 2 million tonnes per year for the present level of production. But real savings in emission will be realised by replacing grey hydrogen with green hydrogen.Use of green hydrogen in the production of ammonia can be achieved by putting up grass-root green ammonia plants and scrapping of existing plants. But this option has two major challenges. One is the huge capital investment required for new capacity with scrapping of efficient grey ammonia plants. The second challenge is that more than 80% of nitrogen application in India is through urea. Production of urea requires two inputs, that is, ammonia and carbon dioxide. The production process of grey ammonia generates carbon dioxide in situ, which comes from carbon in fossil fuel. Production of urea with green ammonia will require a huge quantity of pure carbon dioxide from external sources. This will not be easy and has its own techno-economic challenges.It will be much more prudent that initially, green ammonia can be used to ma