Green Hydrogen a Must to Support Green Revolution

While green fertilisers are good for the world, the government cannot force farmers to adopt them without considering their impact on yield and national food security. The country, therefore, needs to switch to local sources to manufacture synthetic fertilisers.

In India, farmers typically use three types of synthetic fertilisers — urea, Diammonium Phosphate (DAP) and Muriate of Potash (MOP). Urea is by far the most used fertiliser in the country, followed by DAP and MOP.

Urea is manufactured through a multi-step chemical reaction involving natural gas and air. In this process, natural gas is made to react with steam to produce hydrogen, which is then combined with nitrogen from the air to create ammonia. Subsequently, ammonia is made to react with carbon dioxide at high temperature and pressure to form liquid urea, which is then dried into solid prills.

Hydrogen, which is produced by using natural gas, is called grey hydrogen as it is polluting in nature. The cleanest form of hydrogen is Green Hydrogen, which can be produced through the electrolysis of water powered by solar power. The government can use the enormous water resources available in rivers originating from the Himalayas. It can give a big boost to the economies of Uttar Pradesh, Bihar and West Bengal.

Coal gasification is another way to produce hydrogen without depending on imported natural gas. The process is simple. Gas is produced using coal. This gas is used to react with steam to produce hydrogen, which will subsequently be used to produce urea.

Diammonium Phosphate is produced by a chemical reaction between phosphoric acid and ammonia. Rock phosphate is treated with sulfuric acid to produce Phosphoric acid. This acid is then neutralised with ammonia to form a slurry, which is granulated and dried into the final DAP product. India is one of the world’s largest producers of sulfur. But it does not have high-quality rock phosphate, and it is imported from Morocco, Egypt and Jordan.

About 10 per cent of the demand is met from local mines in Rajasthan and Madhya Pradesh; some part of the current demand could be met by installing "struvite reactors" in Sewage Treatment Plants (STPs) in cities.

Rock phosphate is available in various countries such as China, Morocco, Russia, the US, Brazil, Saudi Arabia, Egypt, Tunisia, and it cannot be controlled by any group of countries.

India imports the entire Muriate of Potash. However, Potash Derived from Molasses (PDM) is a waste-to-wealth initiative that converts a highly polluting liquid by-product of sugar distilleries into a valuable agricultural nutrient. It provides an indigenous alternative to imported Muriate of Potash (MOP), which could end India's dependency on foreign potash. To encourage its production, the central government has included PDM under the Nutrient-Based Subsidy (NBS) scheme.