Greenhouse gas emissions from human activities cause global warming [1]. Over the past decade, the average annual temperature has averaged 1.09°C higher compared to 1850-1900. The temperature rise is expected to exceed 1.5°C over the next 20 years. [2]. The Paris Agreement aims to focus efforts on limiting this increase to 1.5°C by 2100 compared to the pre-industrial levels [3].
The energy sector accounts for over 60% of the world's greenhouse gas emissions from fossil fuels. The atmospheric concentrations of CO2 are currently at 417 ppm (3 ppm more than last year) directly affecting the climate change [2].
The European Union has a plan to achieve climate neutrality by 2050 with an interim target to reduce greenhouse gas (GHG) emissions by at least 55% by 2030 [4]. A Net Zero transition requires all states to significantly strengthen their climate policies. [5, 6]. Russia is one of the world's largest GHG emitters, accounting for about 5% of total GHG emissions [7]. Nevertheless, over the past 30 yr, GHG emissions from the industrial sector have decreased by more than 30% as a result of the use of less carbon-intensive technologies, as well as due to equipment modernization. Net greenhouse gas emissions in 2021 are at 1584 million tons of CO2-eq. At the same time, the fuel and energy complex accounts for about 900 million tons, which requires the modernization and transformation of the entire chain of production, transportation and consumption of energy. The current vector of Russia's development is aimed at reducing emissions to zero by 2060.
There are more than 600 technological solutions [8] allowing to achieve Net Zero commitments. TRL 9 reached no more than 30% of technological solutions. In general terms they can be divided into 4 categories corresponding to the 4R concept (Reduce, Reuse, Remove, Recycle) [9]:
Reduce – reducing CO2 emissions through improved energy efficiency and the introduction of hydrogen, nuclear and renewable energy technologies;
Reuse – capturing and utilizing CO2, recycling CO2, by repairing, regrinding and refurbishing equipment;
Remove – CO2 capture and storage, sequestration by natural ecosystems;
Recycle – development of bioenergy.
Hydrogen technologies, along with renewable energy sources and carbon capture and utilization technologies (CCUS) are key instruments for decarbonizing the global energy system. The share of hydrogen in the total final energy consumption is expected to grow from less than 0.1% in 2020 to 10% in 2050. Hydrogen will help avoid up to 60 Gt of CO2 emissions in 2021-2050, which is 6.5% of the total cumulative emission reductions [10]. The development of hydrogen energy directly contributes to the implementation of the Sustainable Development Goals (SDGs), developed by the UN General Assembly. Prioritize Goal 7: Affordable and clean energy and Goal 13: Climate action.
The energy potential of hydrogen lies in its ability to accumulate chemical energy, serve as an energy source and a raw material for various industries. Today, most of the hydrogen is produced from fossil fuels, mainly by steam reforming of methane, and only about 4% of the world's hydrogen comes from water electrolysis [11]. In the context of the transition to Net Zero, the production of electrolytic hydrogen from water and the use of renewable energy sources are in priority. Electrolysis is the electrochemical decomposition of water (H2O) into hydrogen (H2) and oxygen (O2) under the impact of electricity in accordance with the Eqs. (1), (2) and (3) [12]:
Anode∶ H2O (l) → \(\frac{1}{2}\)O2+ 2H+ + 2e− (1)
Cathode∶ 2H+ + 2e− → H2 (2)
Full reaction∶ H2O (l) → H2 + \(\frac{1}{2}\)O2 (3)
Currently, electrolytic projects with a total capacity of more than 20 GW are being announced all over the world, they vary according on the stages of development. Over the past several years, more than 80 of the world's largest companies with revenues exceeding US $ 2.6 trillion have joined the Hydrogen Council, a leading initiative for industries using hydrogen as an energy solution [13]. The Russian Federation, with its significant natural reserves, has all the necessary resources, financial, scientific, and technological foundations for the development of hydrogen energy domestically, as well as for the export. The purpose of this work is to determine the development prospects and priority areas for electrolysis technologies in Russia in the short and long terms.
There are three main electrolysis technologies, depending on the type of electrolyte used:
alkaline electrolysis with liquid electrolyte (AEL) [14], incl. electrolysis with anion exchange membranes (AEM) [15];
proton-exchange membrane electrolysis (PEMEL) [16];
high-temperature electrolysis with solid oxide electrolyte (SOEL) [17].
Comparative characteristics of electrolysis technologies are presented in the Table 1.
Table 1
Comparative characteristics of electrolysis technologies.
Parameter | AEL | PEMEL | SOEL |
Efficiency (system), kWh kg−1 H2 | 50-78 | 50-83 | >90 |
Voltage range, V | 1.4-3 | 1.4-2.5 | 1.0-1.5 |
Nominal current density, A cm−² | 0.2-0.8 | 1-2 | 0.3-1 |
Operating temperature, °C | 70-90 | 40-60 | 700-850 |
Lifetime (stack), h | 60 000 | 50 000-80 000 | <20 000 |
System startup time, min | 20-120 | <1 | >300 |
Capital Costs (system), US $ kW−1 | 500-1100 | 700-1800 | >2000 |
It should be noted that the climate agenda has a significant impact on the development of both the global and Russian economies. In July 2021, the European Commission published a regulation on the Carbon Border Adjustment Mechanism (CBAM) [18] that will be launched on January 1, 2023. CBAM will primarily affect the chemical and metallurgical industries. Industry, which accounts for 38% of total energy demand, is the largest end-use sector and contributes 26% of the global energy system's CO2 emissions. The industrial sector emits 8.7 Gt of CO2. The industry's demand for hydrogen is at 51 million tons per year. [19].
Steel production is the largest industrial subsector, accounting for about 7% of total global CO2 emissions [20]. In the breakdown of greenhouse gas emissions in Russia, the industrial sector accounts for about 11% [21]. The industrial sector is faced with the challenge of meeting growing demand for products while reducing CO2 emissions. For Russia as an exporter of carbon-intensive metallurgical products (Russia’s steel exports amounted to 31.5 million tons [22] in 2020) a number of significant threats arise, primarily associated with financial risks.
This work presents a model project for decarbonization of the direct reduction of iron ore for the production of green steel using electrolytic hydrogen. In addition, a region of the Russian Federation is selected for a pilot project.