[ TECHNOLOGY ]
CO 2 ( or nitrogen ) for Enhanced Oil Recovery ( EOR ). Importantly , already leading DRI producing plants are found there as well , for example , in Iran ( 35 Mt of DRI per annum ), Russia ( 8 ), Saudi Arabia ( 7 ), Egypt ( 6 ), Mexico ( 6 ), USA ( 5 ), United Arab Emirates ( 4 ), Algeria ( 3 ). In many of these countries the price of natural gas is below 4 $/ MMBTU , i . e ., it can result in a cost of blue hydrogen below 2 $/ kg .
Blue DRI
There are two options to produce DRI using carbon capture , i . e ., to produce “ Blue DRI ”:
• Apply CCS on the hydrogen supply and use the resulting blue hydrogen as a reducing gas , which would bring down the carbon footprint of the DRI to 0.15-0.25 .
• Use natural gas and apply CCS on the DRI production , which would bring down the carbon footprint of the DRI to 0.25- 0.35 . Roughly 40 % of the CO 2 emissions from the DRI process can be captured from the top gas from the DRI shaft , while the balance needs to be captured from the flue gas stream . Capture from the top gas is more economical than capture from the flue gas , however , both need to be implemented for full decarbonisation of the DRI process .
The produced Blue DRI would then be fed into an adjacent electric furnace – either an EAF or an electric smelting furnace – producing a steel with a carbon footprint at around 0.8 , or lower if a certain amount of scrap is also used . The Blue DRI , after being processed into Hot Briquetted Iron ( HBI ), can also be shipped to steel mills at other geographical locations to be used as feedstock there .
Moreover , HBI can be used in integrated steel mills to decrease CO 2 emissions . HBI can be charged into blast furnaces or even steelmaking converters to achieve decarbonisation . As a rule-of-thumb , each 10 % increase in burden metallisation in a blast furnace by the addition of HBI increases the production rate by 8 % and decreases the coke rate by 7 %, with attendant CO 2 savings .
For coal based DRI production , which today predominantly takes place in India and to such a scale it makes India the world ’ s largest DRI producer , the concept of Blue DRI is more difficult to apply . However , for production of Blue DRI there is the interesting opportunity to use a syngas from sources beyond natural gas , e . g ., from gasification of biomass or waste , and combine that with CCS .
Shipping of Blue DRI in the form HBI seems a very competitive alternative to potential shipping of hydrogen . The same is of course also true for HBI produced by use of green hydrogen . An expected increase of such HBI trade might bring about dislocations of the steel industry ’ s supply and value chains .
It is important to put the cost of CCS in the context of the alternatives . Currently the cost of CCS can be similar to that of the EU CO 2 emission allowances . Going forward , the cost of CCS is likely to decrease , whilst the cost of the CO 2 emission allowances will increase due to the continuous reduction of free allocations . This cost comparison would be valid both for production within in the EU and for exports to the EU considering the Carbon Border Adjustment Mechanism ( CBAM ). In the USA , the Investment Reduction Act ( IRA ) can provide investors a $ 180 per ton credit for removing carbon using CCS .
Over the next decades a large transition will take place , but it will take time and involve multiple solutions – some more of incremental in their nature , some more disruptive – and the pace will be different in different parts of the world . The drive from the market to produce steel with a low carbon footprint and availability of a viable supply of clean energy are two important factors . A further expansion of DRI production paired with an increasing availability of recycled scrap would gradually replace blast furnace-based iron as the main source for steel production . Production and use of Blue DRI could be an important contributor in this transition .
30 Green Steel World | Issue 10 | February 2024