Dry reforming and blast furnace top gas recycling via an electrically assisted syngas smelter with plasma torches for syngas tuyere injection

This technology, designated as EASyMelt, allows maintaining blast furnace operation with recycling of the blast furnace top gas through a dry reformer used to produce syngas which is subsequently injected in the blast furnace at the shaft level and/or electrically heated using plasma torches prior injection at the tuyere level. In addition, it provides the flexibility to use ammonia crackers for production of hydrogen which can be injected at the tuyere level.

INNOVATIVE TECHNIQUE DESCRIPTION
The EASyMelt concept combines several technologies including the following:

• EASyLooper: Syngas production through dry reformers;
• EASyPlasma: Syngas injection at the shaft level and/or syngas injection at the tuyere level after superheating using plasma torches;
• EASyCraker: Flexibility to utilise directly cracked ammonia depending on the availability of raw materials and process gases on site.

With the EASymelt concept, the BF top gas is recycled and brought back into the system through a dry reforming stage which is considered more efficient given that the CO2 present can be converted into CO. In addition, if pure green hydrogen is readily available, it can also be introduced into the reformer. As a result, a syngas with high H2 content is generated in the reforming process. The output temperature of syngas from the reformer is around 1200-1400°C. This is then superheated to temperatures ranging from 1700-2200° using plasma torches. Injecting the hot syngas with an excellent reducing power into the furnace significantly reduces the coke rate. In the EASyMelt process, the coke requirement for energy supply and reduction purposes is widely suppressed, requiring only a minimal amount of coke for mechanical and alloying purposes.


 Syngas dry reformer technology (EasyLooper): Syngas is generated through dry reforming reactions involving carbon dioxide from blast furnace gas (BFG) and a hydrocarbon source, preferably coke oven gas (COG), although natural gas (NG) can also be utilised. This process follows the specified reaction scheme: CO2 + CH4 → 2CO + 2H2. The heat for the endothermic reaction is provided by combustion of BFG during the heating cycle.
Since 2021, SMS has been operating such reformer at its pilot plant in Dillingen, producing syngas at temperatures ranging from 1200°C to 1400°C using COG and BFG from the steel plant. The plant achieved a methane conversion rate of over 97%, resulting in a syngas reduction ratio of up to 48 (CO+H2 / CO2+H2O).

 Plasma torch technology (EasyPlasma): The electric plasma energy being part of the EASyMelt technology allows for superheating the syngas for injection at the tuyere level and therefore allowing for further reduction of coke rate in the process. SMS Group integrated a 350 kVA plasma torch into the dry reformer pilot plant at Dillinger Hütte to directly superheat the syngas produced from industrial gases with right conditions to be injected directly into blast furnace.

 Ammonia cracker technology (EasyCracker): In this approach, ammonia is heated and cracked into H2 and N2 (by the following reaction scheme: 2NH3 → N2 + 3H2), then super-heated for tuyere injection. Top gas is used as a heating source for ammonia cracking. The hot cracked ammonia is directly injected into the blast furnace without intermediate cooling, allowing for utilisation of the full thermal energy. The raw cracked ammonia does not need to be cooled and separated into N2 and H2, also a very energy intensive process, and can be injected as mixture directly instead.

 Shaft injection: Operational challenges of the EASyMelt due to very low coke feed can be overcome by shaft injection, which allows for the bypassing of the cohesive zone, where permeability issues and flooding are most likely to happen. Top gas temperature is also positively impacted by shaft injection, enabling for high HBI utilisation, and especially also the use of low grade HBI.

DEGREE OF MATURITY

Although each part of the EASyMelt technology is being tested separately, a full integrated plant is yet not been deployed. Therefore, the overall TRL level of the EASymelt concept is not available but the TRL of each individual technology is as follows:

 Syngas dry reformer technology (EasyLooper): This technology, tested at the pilot scale in Dillinger Hutte, has reached TRL 7.

 Plasma torch technology (EasyPlasma): This is in operation since the beginning of 2025. Additionally, a larger-scale plasma torch of 1,6 MVA is under construction with the aim to begin operations in the third quarter of 2025. Currently, this technology has reached TRL 6.

 Ammonia cracker technology (EasyCracker): Ammonia crackers are already used industrially in small sizes with high degree of maturity.

 Shaft injection: Shaft injection has a TRL of 9, it has been previously tested successfully in Cockerill furnace BF3 in Belgium.

An engineering study has already explored the transition from a conventional industrial blast furnace to the EASyMelt system for Blast Furnace “E” at Tata Steel in Jamshedpur, India. This development aiming to demonstrate the EASyMelt concept in a large industrial scale can be carried out in successive stages. No critical technical barrier is identified and the project is under final investment decision for its implementation phase in India.


CROSS-MEDIA EFFECTS (TRADE-OFFS)

 The EASyMelt operation is characterised by an increased hydrogen load in the blast furnace, which leads to a higher generation of condensates in the gas cleaning plant blow down. Furthermore, due to different operation of the furnace, higher amounts of cooling water can be expected.
 Working with higher concentration of flammable and explosive process gases such as CO and H2 requires addition safety considerations, for (i) ensuring compatibility with required tightness and (ii) mitigating risks associated with explosive atmospheres through careful consideration of the Atmospheres Explosibles (ATEX) zones. This is particularly relevant around the tuyere platform areas.

Basic information about the technique

Participant Companies