80
5 Empirical Research for Establishing the Potential of Renewable Hydrogen …
The BF-BOF steel manufacturing process does not require hydrogen as the
reduction of the iron ore is done by the carbon contained in the coke. The reduction process can be decarbonised by injecting hydrogen together with the coke.
The injection of 27 kg of hydrogen per ton of pig iron produced can reduce the
CO 2 emissions by 20% (Dolci 2018). The calculations for the hydrogen demand
from the steel manufacturing considers two options. The option (a) corresponds to
the carbon abated BF-BOF process by injecting 0,0027 t of hydrogen per ton of
iron pig produced. The option (b) considers the substitution of the BF-BOF process by the carbon free DRI-EAF process where the reduction of iron ore is done
entirely by hydrogen (Vogl, Åhman, and Nilsson 2018). The DRI process is also
used for the manufacturing of steel from recycled metal. Therefore, the hydrogen
demand from the DRI process shall distinguish the manufacturing of virgin steel
from iron ore path from the recycled metal path which is a 50%/50% mix of iron
ore and recycled metal. The DRI process requires 0,0051 ton of hydrogen per
ton of steel produced from iron ore and 0,0025 ton of hydrogen per ton of steel
produced from recycled metal (Vogl, Åhman, and Nilsson 2018). The hydrogen
demand of the option (b) is calculated assuming that all the steel manufactured
via BF-BOF is now manufactured via DRI-EAF process considering the recycled
metal share when applicable. As of today, none of the study cases are manufacturing steel with the DRI process at industrial scale (World Steel Association 2019).
The calculation of the hydrogen demand from the DRI-EAF steel manufacturing
process is done for estimation purpose, should the BF-BOF steel manufacturing
process be completely decarbonised. The share of recycled metal manufacturing
is increasing globally (Åhman et al. 2018). It is however still low for the case
studies with 32% in Japan, 39% in Korea and only 11% in China compared to
54% in the EU and 72% in the US. The author assumes a 30% share for Australia
and Taiwan.
Once the production data and conversion factors are defined, the author
calculates the hydrogen demand as shown in table 5.10.
As the hydrogen demand is calculated, the corresponding electricity demand
to produce hydrogen from water electrolysis can be determined. The PEMEC
technology is becoming the leading technology due to its superior characteristics
for intermittent operations, consistent with the renewable electricity energy supply. 59.94 kWh of electricity are required to produce 1 kg of hydrogen (Schmidt
et al. 2017). Hydrogenics®, a manufacturer of PEMEC water electrolyser, indicates that + /– 55 kWh of electricity are required to produce 1 kg of hydrogen
(Hydrogenics 2018). The author uses 55 kWh for the calculations displayed in
the table 5.11.
5 Empirical Research for Establishing the Potential of Renewable Hydrogen …
The BF-BOF steel manufacturing process does not require hydrogen as the
reduction of the iron ore is done by the carbon contained in the coke. The reduction process can be decarbonised by injecting hydrogen together with the coke.
The injection of 27 kg of hydrogen per ton of pig iron produced can reduce the
CO 2 emissions by 20% (Dolci 2018). The calculations for the hydrogen demand
from the steel manufacturing considers two options. The option (a) corresponds to
the carbon abated BF-BOF process by injecting 0,0027 t of hydrogen per ton of
iron pig produced. The option (b) considers the substitution of the BF-BOF process by the carbon free DRI-EAF process where the reduction of iron ore is done
entirely by hydrogen (Vogl, Åhman, and Nilsson 2018). The DRI process is also
used for the manufacturing of steel from recycled metal. Therefore, the hydrogen
demand from the DRI process shall distinguish the manufacturing of virgin steel
from iron ore path from the recycled metal path which is a 50%/50% mix of iron
ore and recycled metal. The DRI process requires 0,0051 ton of hydrogen per
ton of steel produced from iron ore and 0,0025 ton of hydrogen per ton of steel
produced from recycled metal (Vogl, Åhman, and Nilsson 2018). The hydrogen
demand of the option (b) is calculated assuming that all the steel manufactured
via BF-BOF is now manufactured via DRI-EAF process considering the recycled
metal share when applicable. As of today, none of the study cases are manufacturing steel with the DRI process at industrial scale (World Steel Association 2019).
The calculation of the hydrogen demand from the DRI-EAF steel manufacturing
process is done for estimation purpose, should the BF-BOF steel manufacturing
process be completely decarbonised. The share of recycled metal manufacturing
is increasing globally (Åhman et al. 2018). It is however still low for the case
studies with 32% in Japan, 39% in Korea and only 11% in China compared to
54% in the EU and 72% in the US. The author assumes a 30% share for Australia
and Taiwan.
Once the production data and conversion factors are defined, the author
calculates the hydrogen demand as shown in table 5.10.
As the hydrogen demand is calculated, the corresponding electricity demand
to produce hydrogen from water electrolysis can be determined. The PEMEC
technology is becoming the leading technology due to its superior characteristics
for intermittent operations, consistent with the renewable electricity energy supply. 59.94 kWh of electricity are required to produce 1 kg of hydrogen (Schmidt
et al. 2017). Hydrogenics®, a manufacturer of PEMEC water electrolyser, indicates that + /– 55 kWh of electricity are required to produce 1 kg of hydrogen
(Hydrogenics 2018). The author uses 55 kWh for the calculations displayed in
the table 5.11.