The photo is sourced from DALL-E
Blue hydrogen is produced by steam reforming methane and using carbon capture, utilisation and storage (CCUS) systems, whereas green hydrogen is produced by splitting water into oxygen and hydrogen via electrolysis units powered by renewable energy sources. The development of infrastructure for the production of blue hydrogen is de facto linked to the introduction of CCUS technologies, including CO2 capture using monoethanolamine (a colourless liquid with a slight ammonia odour that absorbs carbon dioxide very well) and metal-organic frameworks – lattice structures made of metal and organics that are capable of holding foreign substances and later releasing them due to changes in temperature and pressure.
According to the Energy Institute, global CCUS capacity increased by 7% in 2023, reaching 55 million tons per year, which is comparable to annual CO2 emissions from associated petroleum gas (APG) flaring in Russia (59.4 million tons in 2023). The use of CCUS systems drives up the cost of hydrogen production: the Oxford Institute of Energy Studies (OIES) estimates that H2 production using methane reforming costs an average of $1.5–1.8 per kg (depending on the cost of gas), whereas the use of CCUS technologies causes specific costs to increase to $2.1–2.4 per kg. Meanwhile, the cost of producing green hydrogen varies from $3.3 to $6.5 per kg, depending on the cost of clean electricity and the type of electrolyser used.
Two types of electrolysis units are most common today: alkaline electrolysers, which use a liquid electrolyte solution to produce H2, and proton exchange membrane units, which use a solid polymer electrolyte. Both types of units operate at a temperature of 80 degrees Celsius. An alternative is solid oxide electrolysers, which require thermal energy and operate at a temperature of 1,000 degrees Celsius.
Overall, blue and green hydrogen production technologies are at approximately the same stage of commercialisation as LNG transportation technologies were in the 1960s, when the construction of the first specialised tankers for intercontinental transportation of liquefied natural gas began. The emergence of new consumer groups, including in the power industry and transport, takes place at the same time as the formation of H2 production clusters. Among them could be the Baltic Sea coast, with its excess wind generating capacity and a dense network of gas pipelines that can be upgraded to transport H2.
