Thursday, 27 May 2021
The Italian transport group Snam has set a first by using a 30% hydrogen/gas blend to power steelmaking furnaces in northern Italy. The trial was carried out at a plant in Milan owned by the Italian steel manufacturing Giva Group, with the long view of promoting green hydrogen usage.
Trials have been labelled a success, and is considered a pioneering stage to eventually introduce zero-emission hydrogen in certain processes. Giva estimates that utilising a 30% green hydrogen blend would lead to emissions reductions of 15 000 tonnes CO2 per year in their operations.
"Snam intends to make its infrastructure, research and expertise available to contribute to the creation of a national hydrogen supply chain and to the achievement of domestic and European climate targets," Snam Chief Executive Marco Alvera said.
Snam, Europe's largest pipeline operator, has previously been trialling hydrogen mixtures (up to 10%) in its natural gas network, claiming 70% of its grid is 'hydrogen ready'.
Hydrogen, like natural gas, is an energy carrier and in many applications can be substituted directly. The promise of hydrogen as an energy carrier is tied to the ability to produce renewable hydrogen. Green hydrogen is one of the forms of renewable hydrogen, where the gas is produced via electrolysis, and the supplied electricity used in the process is from net-zero sources.
While green hydrogen has value as a renewable energy source, in many cases it will be more convenient to directly employ renewable electricity. However, hydrogen can be used for non-energy purposes. As suggested above, steelmaking is a promising area where hydrogen is used for non-energy purposes. Coke which is typically used as a refining (reducing) agent in steelmaking can be substituted with hydrogen; where coke usage has associated carbon emissions, hydrogen usage simply results in water as a by-product.
Unfortunately, green hydrogen production is still costly, with the main burden being the price of renewable electricity. This is in addition to the cost of upgrading industrial process equipment to utilise hydrogen instead of traditional fossil fuels. However, the price of green electricity is expected to drop over the coming years, with support from governments for green hydrogen production also improving viability.
Blending and transporting hydrogen via natural gas pipelines with minimal treatment is possible in theory. However, the effects of hydrogen embrittlement (the interaction of hydrogen with steel/plastic) could compromise transport pipelines, which has resulted in this transport arrangement being adopted slowly and cautiously. Lower hydrogen blends however are of less concern than higher purity hydrogen streams.
Tracking systems for renewable hydrogen are required to preserve green attributes after blending with fossil gas. Such systems are in development. Currently, the only existing register tracking renewable hydrogen in appreciable volumes is the EU CertifHy project, which is a Guarantees of Origin scheme, similar to the widely employed book-and-claim system used for renewable electricity. The RED II has suggested the RES-E scheme be extended to encompass renewable gases, which includes green hydrogen and the more widely produced biomethane.