The Decarbonizing Capability of Hydrogen: A Source to Reduce Emissions in Iron and Steel Production
The steel production, which emits about 7% global CO₂, was evaluated by RFF’s Jay Bartlett and Alan Krupnick through the decarbonization process under Hydrogen and CCUS.
This article is aimed to look at the recent report and to compare the other sources of reducing carbon emissions like carbon capture, utilization, and storage (CCUS) and Electrification with zero-carbon power with hydrogen decarbonization. This comparison and evaluation of other options of decarbonized Hydrogen By evaluating decarbonized Hydrogen against these other two methods of reducing CO₂ emission help us to know when, where, and how the use of Hydrogen for reducing CO₂ emissions can be a cost-effective method.
How the “blue” and “green” Hydrogen and decarbonized Hydrogen can effectively be used for reducing CO₂ emissions from oil refining and ammonia production was the primary concern of previous blog posts. But, these articles will inspect how the use of Hydrogen for heat and energy storage and policy mechanisms can be effective for reducing CO₂ emission in the industrial and power sector.
It can be seen that in feedstock applications, along with the replacement of “grey” or “brown” Hydrogen with “blue” or “green” Hydrogen, the decarbonized Hydrogen displaces coal feedstock and natural gas and helps in further reduction of emissions. It is also found that nowadays, the prominent use of decarbonized hydrogen feedstock will be a good opportunity in iron and steel production because such productions emit almost 3 billion tons of CO₂ ( 7% of global CO₂ emissions). Besides, it is not necessarily be said that the use decarbonized Hydrogen despite high-carbon feedstock can only benefit iron and steel production.
Although Decarbonized hydrogen is also useful in the production of methanol and urea, here is a little problem that the use of this method in such industry may demand a non-emitting source of carbon like direct air capture along with the use of decarbonized Hydrogen. That’s why, in this article, we will just deal with iron and steel production and the evaluation of decarbonized hydrogen usage versus CCUS applied to emissions from natural gas or Coal to know which method is best and effective for the reduction of steelmaking emissions.
The manufacturing of Steel happens under the two phases of productions, the primary production, for first converting iron ore into iron and later into Steel while the secondary production is for recycling of scraped Steel. The primary production process mostly processes through the blast furnace–basic oxygen furnace (BF-BOF) route, though the primary steel production in a smaller amount happens through the process of direct reduction of iron (DRI) processed in an electric arc furnace (EAF).
However, secondary steel production is less energy-intensive that is done in an EAF. The quantities of both primary and secondary steel production by methods in the United States and globally are shown in table 1. Here we see secondary display gives 66% of US steel production through the EAF method, while globally, it only produces 22% of Steel. So this article is also for exploring the BF-BOF and DRI-EAF steelmaking methods and inquiring about different options and sources for deep decarbonization.
The BF-BOF steelmaking processes in a way that iron ore, coke (high-carbon Coal purged of volatile compounds), and limestone are put to a blast furnace, here the reaction of the iron ore with carbon monoxide to produce high-carbon crude iron and CO₂. At a later stage, the iron is shifted to a basic oxygen furnace, where it includes the combination of oxygen and some of the carbon to produce low-carbon Steel and additional CO₂. The whole BF-BOF process, along with combustion, produces almost 1.73 tons CO₂ per ton of Steel.
In the blast furnace, the Coal is the key element to the BF-BOF method because the reaction offers heat, carbon monoxide, and physical structure to the furnace. As a result, at a large scale, it is not possible to entirely substitute Coal with a low-carbon source like decarbonized Hydrogen. However, in some biomass-rich countries like Brazil, the charcoal has effectively been utilized. The amount of Coal consumed in BF-BOF steelmaking can easily be reduced by Hydrogen, but such action may decrease CO₂ emissions.
The CCUS seems with a high potential globally for decarbonizing the BF-BOF process. Besides, feedstock and fuel substitution has the involvement of some technical challenges. An emissions reduction of 47 to 60 present has been estimated by reviewing three techniques in BF-BOF steel production under CCUS integration CCUS. In the pre-commercial “demonstration” phase, the emissions-intensive steps of sintering (agglomerating iron ore) and coking has been eliminated by HIsarna process to achieve further CO₂ reductions. There are possibilities of 80 to 90 present reductions in CO₂ emissions If HIsarna steel production is integrated with CCUS.
In India, coal-based DRI-EAF is common, and the first step in the production of grey or blue Hydrogen seems in bulk, as the majority of DRI-EAF steelmaking involves the reforming of natural gas to produce a mixture of carbon monoxide and Hydrogen. For the reduction of iron ore in a furnace, both carbon monoxide and Hydrogen are utilized and then they also solid iron, steam, and CO₂. Now the iron is mixed into scrap steel and then melted in an electric arc furnace for removing impurities from it and produce molten Steel. Table 2 manifests a clear difference and shows that CO₂ emissions of natural gas-based DRI-EAF steelmaking is about half than the emissions of BF-BOF production. The lower CO₂ emission of natural gas-based DRI-EAF is due to the high efficiency of feedstock and fuel use. Besides, the lower carbon content of natural gas than Coal is also a reason.
Table 2. The states of Energy and Emission Potential in Steelmaking Process
International Energy Agency offers Energy intensities to feedstock and fuel, but H₂ DRI-EAF sources from HYBRIT. As per the US Energy Information Administration, the average CO₂ intensity of the US grid has been assumed by Electricity emissions for BF-BOF and Natural Gas DRI-EAF. Sources: International Energy Agency (2019); HYBRIT (2018); US Energy Information Administration (2020a, 2020b).
According to Table 2, if the energy is utilized from zero-carbon sources instead of the US grid, we can reduce 35% emission from natural gas-based DRI-EAF. The elimination of electricity emissions causes retaining of CO₂ that comes out of the use of natural gas for reducing iron ore, this ultimately brings to channels for the deep decarbonization of DRI-EAF steelmaking. Firstly, the DRI reactor can be dealt with CCUS application that can effectively capture CO₂ from the reduction of iron ore. The United Arab Emirates has already applied this technology in commercial operation. Secondly, the substitution of pure Hydrogen in place of natural gas can decarbonize the direct reduction of iron, in Sweden, HYBRIT project presented this technology. Recently, in the pre-demonstration “pilot” phase, for the production of Steel with minimal emission, HYBRIT is planning to utilize zero-carbon Hydrogen along with renewable power and sustainable biomass.
It’s optional that we choose the type of decarbonized Hydrogen—blue or green as per our interest for hydrogen-based DRI-EAF steelmaking. Our previous article aimed for decarbonized Hydrogen in existing feedstock applications, it was shown that blue Hydrogen is less expensive than green Hydrogen. Although, as the DRI process permits for CCUS, so first we should compare and evaluate blue Hydrogen–based DRI-EAF (i.e., capturing CO₂ before use in DRI) versus natural gas-based DRI-EAF with CCUS (i.e., capturing CO₂ after use in DRI). Such comparison might show natural gas-based DRI-EAF with CCUS to be more cost-effective than blue Hydrogen–based DRI-EAF. Green Hydrogen contains a production process that is different from natural gas, and green Hydrogen serves as a source for decarbonized Hydrogen in steel production.
If the methods like BF-BOF and DRI-EAF steelmaking are observed, then three pathways, including HIsarna with CCUS, natural gas-based DRI-EAF with CCUS, and green Hydrogen–based DRI-EAF, have a high potential for 80 % cost-effective reduction in emissions or even more if the predominant process is BF-BOF. These processes can further be improved with profound research and development.
What if the cost of green Hydrogen–based DRI-EAF is compared with the costs of HIsarna with CCUS and natural gas-based DRI-EAF with CCUS? So this question is well answered by The International Energy Agency, which concludes that a price of $0.70–$2.00 per kg H₂ is required for green Hydrogen–based DRI-EAF for the production of Steel at the parallel cost to natural gas-based DRI-EAF with CCUS. The high variation in natural gas prices is due to the high range price breakdown of Hydrogen; now, the areas with low natural gas prices (and CO₂ storage) would find natural gas-based DRI-EAF with CCUS particularly competitive. A breakeven price range of $1.20–$1.60 per kg H₂ has been estimated by the Hydrogen Council for turning green Hydrogen–based DRI-EAF competitive with HIsarna and 90 present CCUS. The midpoint of these two ranges (about $1.40 per kg H₂) is effectively reachable for the delivered price of green Hydrogen over the long term. But, these costs of production, storage, and transportation are required to be declined, as discussed in a previous blog post.
The increase in efficiency and decline in the carbon content of fuel and feedstock may reduce the emissions from steel production. Furthermore, the rise in the magnitude of recycled Steel and Coal to natural gas transition is the most significant measures for the development of decarbonization approaches. A similar potential can be seen in Electrification of heat (e.g., the electric arc furnace), as the average US grid power currently causes high CO₂ emissions, renewable and nuclear power would maintain zero-carbon electric heat. However, the feedstock emissions need to be minimized, either through CCUS or decarbonized Hydrogen, to approach deep decarbonization of steelmaking. Before becoming competitive, Green Hydrogen has a high potential path, but when the zero-carbon power is combined with green Hydrogen, it benefits to enable steel production with minimum emissions.