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  • Green, blue or turquoise? What do these colours mean?

    Although many engineers will grumble at the attribution of colour to this colourless gas, this simplified typology is used to show the source. The most common method of obtaining the gas is steam reforming of natural gas, which produces the so-called grey hydrogen. Analysts estimate that by 2030 the production of zero-emission, 'green' hydrogen will be significantly cheaper. The authors of the Polish hydrogen strategy, however, propose abandoning the colour nomenclature in favour of a precise definition of the emission performance of individual technologies.

    Hydrogen can be obtained from many sources of energy and with the aid of various technologies. The most common, but also the most carbon-intensive way of obtaining hydrogen is from fossil fuels. 76% of such hydrogen production comes from the processing of natural gas (grey hydrogen) and 23% is produced by the high-temperature gasification of coal. Hard coal processing is responsible for the production of so-called black hydrogen, brown hydrogen is created from brown coal.

    The most common method of producing hydrogen is natural gas steam – reforming (SMR), or, less common, autothermal reforming (ATR) The cost in the European Union is estimated at EUR 1.5 per kilogram of hydrogen, but this amount does not include CO2 emission rights fees. The use of fossil fuels to produce hydrogen produces 830 million tonnes of carbon dioxide per year worldwide, which corresponds to 2.5% of emissions from fuel combustion. The majority of Polish hydrogen also comes from fossil fuels.

    As in the case of other processes using fossil fuels, attempts are being made to reduce emissions by installing CCS to recover carbon dioxide and store or reuse it (Carbon Capture Utilisation,CCU) and use and storage it (CCUS). The resulting hydrogen is called blue hydrogen. CO2 capture can be done in several ways - CO2 can be separated from the synthesis gas stream or captured from the flue gas.

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    Hydrogen production plants using CCUS technology are operating in Port-Jérôme, France and at Shell's Rotterdam refinery, among others. The technology captures up to 97% of emissions and increases hydrogen production efficiency by up to 15%. The cost of producing blue hydrogen today has been estimated in the EU strategy at about EUR 2 per kilogram. This is still a niche solution; around 0.5 million tonnes of hydrogen are produced annually in this way in the world.

    Nuclear energy could also be a potential source of energy for producing the 'fuel of the future'. This solution is already being tested by the US Department of Energy, which has allocated USD 20 million to the operation of the 'Hydrogen Shot' project in Arizona. Although initially the production of so-called purple hydrogen was not included in the EU strategy, in 2020 the European Commission classified this type of hydrogen as low carbon. The French company EDF, which has nuclear power plants in the UK, is working on such a formula for hydrogen production. A pilot project, which has received government funding, is to start at the Heysham 2 nuclear plant in the north-west of the British Isles.

    Poland is looking at the possibility of implementing nuclear power as an energy source for hydrogen production after 2030. The low-carbon nature of such produced hydrogen is important here, as is the mass scale of production. In the draft Polish hydrogen strategy, the authors point out that the use of nuclear energy for hydrogen production may prevent periodic power cuts in plants (in the so-called night valleys) by using surpluses to power electrolysers. The advantage of this method is its stability - it does not depend like RES on atmospheric conditions, which allows for more efficient operation of electrolysers and extends their lifetime.

    The European Commission assumes that the production of green hydrogen will be based on electrolysis using energy from renewable sources and indicates the shift of the European economy to zero-emission as its strategic objective. According to the definition valid in the European Union, RES include: solar radiation energy, wind energy, geothermal energy, fall of rivers, waves, sea currents and tides, biogas and biomass. Today, the main barrier to implementing green hydrogen on a large scale is the relatively high prices.

    According to the hydrogen strategy, Poland will focus on hydrogen production using offshore wind energy. The government is planning investments in the Słupsk shoal, in the region of Central Pomerania and Gdańsk, and in the next stage, on the Odra river, among others. Another ecological source of hydrogen that Polish companies are interested in is municipal and agricultural waste. In Trzebinia PKN Orlen will soon launch an installation for the production of biohydrogen from biomass. The investment is being built next to a plant producing ecological propylene glycol. PKN Orlen is also analysing the possibility of producing hydrogen from biomass created during the production of sugar and cereal products.

    In Konin ZEPAK will create Europe's largest biomass hydrogen plant with a total capacity of up to 50 MW. Already today, the biomass-fired power unit at the Konin Power Plant supplies green energy to the city's heating system. In the future, it will also power electrolysers for hydrogen production.

    Currently, the level of hydrogen use in the world is about 115 million tons. In Poland it is about 1.3 million tonnes. According to Bain&Company, hydrogen production may increase up to 300 million tonnes by 2050. However, plans for most hydrogen to be 'green' do not take into account the specifics of waste hydrogen production. Polish experts and authorities point out that the typology of hydrogen based on the source of the fuel does not take into account the broader context of the carbon intensity of the hydrogen production process. Among the provisions of the Polish hydrogen strategy is a proposal to replace the arbitrary attribution of colour to hydrogen with a more precise numerical calculation of its emissivity, that is, the amount of CO2 emitted throughout the production chain per kilogram of hydrogen.

    Low-carbon hydrogen could then come from both non-renewable and renewable sources with a low carbon footprint. The authors of the strategy also suggest that hydrogen created as a by-product of chemical processes could qualify as low-carbon because "the resulting emissions arise from other processes where they are unavoidable". The undoubted advantage of such a hydrogen policy is the costs, which are projected to fall with the standardisation of the CCU/CCS processes used to control emissions in the hydrogen production process.