New Delhi, August 31st (India Science Wire): Hydrogen, the lightest and most abundant element of the universe, holds the potential to change our dependency on fossil fuels. As an energy carrier, it is becoming crucial to achieving decarbonization of hard-to-abate sectors. These are the sectors like aviation, steel, and shipping, for which the transition is not much straightforward for the lack of technology and prohibitive costs.
Traditionally, these sectors have relied on coal, oil, and natural gas and have been some of the largest CO2 emitters. The cost of green Hydrogen generation in India can be brought down by using low-cost renewable energy generating plants. As per a NITI Aayog Report, global demand for Hydrogen could grow by almost 400 percent by 2050, led by industry and transportation. The Ministry of Power (MoP) unveiled the first part of India’s Green Hydrogen Policy on 17 February 2022. It is one of the critical outcomes of the National Hydrogen Mission, launched by Prime Minister Narendra Modi in 2021.
Hydrogen gas on burning (combustion) with oxygen (air) generates a considerable amount of energy, generally 286,000 joules per mole of Hydrogen gas burned. It has a high energy density/mass of 120-142 MJ/kg; for gasoline, it is 44.5 MJ/kg. The process does not produce any toxic combustion by-products. Currently, Hydrogen used for the process is largely produced from conventional fuels.
White Hydrogen is a naturally occurring version that can occasionally be found underground. In the US, nearly 80% of the Hydrogen is produced through Steam-Methane Reforming (SMR), known as grey Hydrogen. The fuel used is natural gas or methane. This process generates just a smaller amount of emissions than black or brown Hydrogen, which uses black (bituminous) or brown (lignite) coal in the Hydrogen-making process. It is the most damaging from the environmental point of view as it generates both carbon monoxide and carbon dioxide.
The Hydrogen is labelled blue whenever the carbon generated from steam reforming is captured and stored underground with the help of industrial Carbon Capture and Storage (CSS). Blue Hydrogen is often referred to as carbon neutral as the emissions are not dispersed in the atmosphere. According to a study conducted by the International Energy Agency, the blue Hydrogen production is responsible for around 830 million tons of CO2 emission annually.
Hydrogen produced with the water electrolysis process (splitting water into Hydrogen and Oxygen) is known as green Hydrogen or “clean Hydrogen” as it is produced by using clean energy from surplus renewable energy sources, such as solar or wind power and biomass. Alkaline and polymer electrolyte membrane (PEM) electrolysers are two commercially available green Hydrogen production technologies. Advanced electrolyser technologies like solid oxide and anion exchange membranes are also nearing commercial deployment.
Reducing emissions from existing Hydrogen production is a challenge but also presents an opportunity to increase the scale of clean Hydrogen worldwide. It is possible by capturing, storing, or utilising the CO2 produced from manufacturing Hydrogen using fossil fuels. There are currently several industrial facilities around the world, including India, that use this process. Efforts should be taken to increase the number of such facilities for enhanced impact. Expanding the use of clean Hydrogen in other sectors – such as transportation, steel, and energy management for commercial buildings would also create more traction.
India has a distinct advantage in low-cost renewable energy generation, which is said to be the factor making it most competitive in green Hydrogen. As per the analysis performed by RMI (Rocky Mountain Institute), adopting green Hydrogen will also result in 3.6 Giga tonnes of cumulative CO2 emissions reductions between 2020 and 2050.
Other than direct combustion, Hydrogen can be consumed by electricity generation through fuel cells and industrial processes to be used as chemical feedstock like fertilizer, plastics, fuel refining, metallurgy, steel, food, and glass industries. India’s first indigenous Hydrogen fuel cell bus was unveiled on 24 August 2022 in Pune, Maharashtra, by Union minister of state for science and technology Dr Jitendra Singh. It is a joint development effort of KPIT Technologies and the National Chemical Laboratory (CSIR-NCL).
In the cell, the Hydrogen is fed to the anode and air to the cathode. A catalyst at the anode separates Hydrogen molecules into protons and electrons, and the electrons going through an external circuit create the flow of electricity, producing only heat and water as tailpipe emissions. A single diesel bus plying on long-distance routes typically emits 100 tons of CO2 annually, and there are over a million such buses in India. Green Hydrogen-run buses will be the right solution to curb such pollution. In addition, it can also help reduce the nation’s reliance on oil imports and strengthen the domestic job market.
Challenges of a Hydrogen economy are high costs, technicalities involving transporting and storing Hydrogen, supply chain complexity, regulations, and policy. The cost of green Hydrogen largely depends on the cost of electrolysers and electricity, operating price, transmission and distribution costs, local duties and taxes, etc. It is relatively high in India and lies between $7-4.10/kg but has the potential to reach $1.60/kg by 2030 and $0.70/kg by 2050. Such aspirational price targets will be conducive to green Hydrogen market development.
India is undertaking a resolute march to scale up green Hydrogen production and utilisation. Bhabha Atomic Research Centre (BARC) has already developed an alkali water electrolysis technology for commercialization that can produce 10 Nm3/hr of Hydrogen. Central Electrochemical Research Institute (CSIR-CECRI) is currently designing electrodes and electrolytes for Hydrogen generation using seawater. The University of Lucknow is exploring the use of transition metal mixed oxides for alkaline water electrolysis and preparing electrodes.
A consortium of institutes, including IIT Kanpur, IIT Madras, IIT Jodhpur, CSIR-CECRI, BARC, and Dayalbagh Educational Institute, is developing a scalable design for a Solar-Hydrogen generation system using multiple technologies. Oil and Natural Gas Commission Energy Centre and IIT Delhi are utilizing the Sulphur-iodine thermochemical Hydrogen cycle to generate low-cost clean Hydrogen fuel for industrial consumption. A research group from the Central Scientific Instruments Organisation (CSIR-CSIO), Chandigarh, headed by Dr Pooja Devi, Principal Scientist, is investigating wastewater as a feedstock for Hydrogen production instead of potable water. It can solve both the problem of wastewater management and clean Hydrogen generation. (India Science Wire)