Cement Manufacturers Association (CMA)

9 major categories, namely, Grey, Blue and Green based on production methodology - Grey Hydrogen It is produced via coal or lignite gasification (black or brown), or via a process called steam methane reformation (SMR) of natural gas or methane (grey). These tend to be mostly carbon-intensive processes. Method - This process is used to produce hydrogen on a large scale in the gas manufacturing industry. In this process, high- temperature steam is used to convert methane, such as natural gas, into pure hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. The hydrogen produced is purified to quality as per desired customer’s specifications. This is the most common & economical way. Blue Hydrogen It is produced via natural gas or coal gasification combined with carbon capture storage (CCS) or carbon capture use (CCU) technologies to reduce carbon emissions. Method - Coal gasification is a process that is used to turn brown coal, which contains a high percentage of oxygen and hydrogen, into hydrogen. In the mid-nineteenth century, coal gasification was used to produce town gas, which was used for local heating, lighting, and cooking. Most of these purposes are now met by natural gas. Gasification converts fuel or waste into a combustible gas mixture through partial oxidation at very high temperatures. Routes for hydrogen production Source: GlobalData Thematic Research, Hydrogen in Mining. Green Hydrogen It is produced using electrolysis of water with electricity generated by renewable energy. The carbon intensity ultimately depends on the carbon neutrality of the source of electricity (i.e., the more renewable energy there is in the electricity fuel mix, the “greener” the hydrogen produced). Method - Electrolysis produces hydrogen by splitting water into H2 and O2 through the application of electricity and it has attracted significant attention due to its potential as a sustainable production process. The electrolysis process was first used commercially in 1890 and although the electrolysis market is currently very small, it is expected to record fast growth in the future. This reaction takes place in a unit called an electrolyzer, which consists of an anode and a cathode separated by an electrolyte. The process of electrolysis takes place at room temperature. There has been some debate recently about what precisely can be referred to as green hydrogen. In February 2023, the European Commission began debating whether hydrogen created using nuclear power (currently known as “pink” or “purple” hydrogen, part of an entire rainbow of hydrogen classifications) may rightly be called “green”. Green hydrogen is being viewed as the next big alternate source of energy revolution. In terms of energy requirements, India’s economy is currently the third largest in the world, and it is estimated that by 2030, the nation’s demand for energy is expected to increase by 35 percent. Grey Hydrogen Produced by applying steam reformation to natural gas. Methane in the natural gas reacts with steam to form hydrogen and carbon dioxie Brown Hydrogen Brown coal is gasified to create a synthetic gas of carbon monoxide, carbon dioxide, hydrogen and steam from which, hydrogen is extracted Purple Hydrogen Produced through water electrolysis powered by nuclear power Green Hydrogen Produced through water electrolysis powered by renewable energy or through gasification of biomass Blue Hydrogen Brown or Grey hydrogen prodiction with CCS or CCUS CO 2 H 2