The government recently announced a Hydrogen Mission. Coal is one of the important sources of hydrogen making (Brown Hydrogen) apart from Natural Gas (Grey hydrogen) and renewable energy (Green Hydrogen) through electrolysis. In case of renewable energy (Green Hydrogen) surplus solar power is used to electrolyze water into hydrogen and oxygen. The global emphasis is on substituting liquid fuels with hydrogen (as fuel in vehicles), storage of surplus renewable power as hydrogen (as power cannot be stored at a cost-effective price), and cutting down emission.
Coal is one of the important sources of hydrogen making (Brown Hydrogen). However, Coal has not been encouraged elsewhere because of the fear that while extracting hydrogen via coal (from the moisture embedded in coal) there may be carbon emission. Almost 100% of Hydrogen produced in India is through Natural Gas.
Globally, 73 MT Hydrogen is used for refining, ammonia making and other pure use and about 42 MT is used for Methanol, steel making and other mixed uses. Cost of Hydrogen produced from coal can be cheaper and less sensitive to imports when compared with hydrogen production through electrolysis and Natural Gas respectively.
Production of hydrogen from coal will have challenges in terms of high emissions and CCUS will play an important role. However, when the carbon monoxide and carbon dioxide formed during coal to hydrogen process are trapped and stored in an environmentally sustainable manner (CCS and CCUS), then, Indian coal reserves could become a great source of hydrogen.
In steel making, lots of work has been done on production of steel by use of Hydrogen. However, iron reduction through hydrogen is an endothermic reaction and will require lot of heat. This heat can be generated in DRI plants due to presence of CO in syn Gas being produced from coal gasification process.
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