Restek
Home / Resource Hub / ChromaBLOGraphy / Hydrogen purification from the steel industry

Hydrogen purification from the steel industry

26 Oct 2022
  • Share:
    linkedin sharing button
    facebook sharing button
    twitter sharing button
    print sharing button

blog-hydrogen-purification-from-the-steel-industry-01.jpg

Let’s talk about the steel industry. People love steel. There are steel appliances, furniture, construction beams and cables, cars, trains (and tracks), tools, medical devices, and even a little bit in the computer you are reading this from. It’s durable, versatile, and abundant, and we have been using it for centuries, so steel production and manufacturing is likely, maybe quietly, a significant part of your life. Following the 2015 Paris Agreement, the steel industry became a much larger part of everyone’s lives, as it was identified as one of the major contributors to carbon dioxide (CO2) emissions1, accounting for an estimated 5% of the world’s total2. This is primarily related to the huge energy demands of the blast furnace where fuel (coke) converts iron ores to useable material for further refinement. Carbon monoxide (CO) produced from the fuel is used as a reducing agent during this process to convert iron oxide to elemental iron and, you guessed it, CO2. Humans have been making steel for thousands of years, likely as early as 1200 B.C., intertwining the material with cultural and economic developments3, which makes its emissions overhaul an especially complicated process. So how do we reduce CO­2­ emissions in such an established process? The answer seems to surround an emerging fuel source: hydrogen.

Hydrogen can be used as a reducing agent in blast furnaces, replacing CO and CO2 with H2 and H2O (water) 4. However, the kinetic behavior of CO and H2 are very different, so steel producers can’t exactly implement a 1:1 substitution and expect the current infrastructure to hold up. While it’s worth noting that H2 seems to offer improved kinetic and diffusion behavior relative to traditionally used CO, working against kinetics is the water produced after reduction4,5. The higher moisture content in the air will require a higher energy demand and may ultimately weaken the structural materials in the furnace4. Instead of immediately moving to hydrogen, some research facilities are exploring using a combination of hydrogen and coke first to better control moisture and material integrity5. Outside of the blast furnace, hydrogen fuel may also be able to supply energy for sintering, palletizing, and the furnace.

So where does the hydrogen fuel come from? Many of these strategies have been summarized in literature (I recommend Liu et al5), and show the significant investment and benefits there may be to improving hydrogen production and utilization as energy. Some of the most promising approaches include reformation of emissions from the blast furnace, reformation of steam methane from natural gas, electrolysis of water, and nuclear. In reformation of emissions and methane, contaminants such as CO, CO2, and CH4 are separated or converted to more H2. Some CO­2 is still produced, but in significantly smaller amounts. Water electrolysis through electric or nuclear means produces higher purity hydrogen with little to no CO2 emission, but the infrastructure would be far more complicated to implement.5

Depending on how the hydrogen is produced, different contaminants may be present. Emissions being purified directly from the blast furnace are likely to contain sulfurous and organic volatiles, whereas H2 produced through nuclear energy is more likely to be contaminated with I2 and SO25. These impurities can contaminate fuel cells, reducing overall efficiency, so it is important that hydrogen gas purity is monitored1,2,5. There are a variety of standardized requirements that have been developed for hydrogen fuel such as ISO 14687:2019, J2719_202023, GB/T 3634.2-2011, GB/T 37244-2018. In addition, ASTM International standards have been developed for testing hydrogen purity. But, we should recognize that these standards were developed based on purity requirements for use in hydrogen-fueled cars, and there is definitely more to learn about what industrial-scale hydrogen fuels and use might look like.

We know Hydrogen too!

We may not be using hydrogen for “fuel” per se, but us analytical chemists need to use and take care of high-purity hydrogen too. While helium sources become scarce (and expensive) there is a push in the world of chromatography to use hydrogen as a carrier gas. You know how substituting CO with H2 isn’t straightforward? Well neither is substituting He with H2. Viscosity decreases, the mass spec behaves differently, retention times shift, and copper plumbing has to be replaced. To manage hydrogen, we offer clean stainless steel plumbing treated to be highly inert. Doesn’t that just sound so helpful for moving around hydrogen, worry-free?

Moreover – it sounds like the steel industry is going to need to keep track of hydrogen purity. Gas chromatography is a low-cost approach for measuring volatile contaminants, which has already been incorporated into a few ASTM methods. But ASTM methods aren’t always one-size-fits all, especially when hydrogen can be produced so many different ways. Are you looking for ammonia and water in your hydrogen? Sulfur compounds? Hydrocarbons? CO and CO2?  We know finding the right column (or two) can be complicated, so we want to help. We have a variety of packed and PLOT columns ideal for separating permanent gases, and capillary columns for when you need to resolve something a little heavier. Need to incorporate a backflush in your method? Add a guard column? Is there contamination in your system? Want to separate at lower temperatures (there’s enough heat involved in steel production already, right?)? We can help!

We want to know more about what analytical challenges steel manufacturers are facing as they work towards reducing CO­2 emissions. If you are interested in seeing more applications from us surrounding hydrogen fuels, tell us in the comments.

Further reading:

  1. Bataille, C.; Åhman, M.; Neuhoff, K.; Nilsson, L. J.; Fischedick, M.; Lechtenböhmer, S.; Solano-Rodriquez, B.; Denis-Ryan, A.; Stiebert, S.; Waisman, H.; Sartor, O.; Rahbar, S. A Review of Technology and Policy Deep Decarbonization Pathway Options for Making Energy-Intensive Industry Production Consistent with the Paris Agreement. Journal of Cleaner Production 2018, 187, 960–973. https://doi.org/10.1016/j.jclepro.2018.03.107.
  2. Zhang, X.; Jiao, K.; Zhang, J.; Guo, Z. A Review on Low Carbon Emissions Projects of Steel Industry in the World. Journal of Cleaner Production 2021, 306, 127259. https://doi.org/10.1016/j.jclepro.2021.127259.
  3. Suenaga, K. The ‘Industrial Enlightenment’ and Technological Paradigms of the Modern Steel Industry. Technology in Society 2020, 63, 101375. https://doi.org/10.1016/j.techsoc.2020.101375.
  4. Spreitzer, D.; Schenk, J. Reduction of Iron Oxides with Hydrogen—A Review. steel research int. 2019, 90 (10), 1900108. https://doi.org/10.1002/srin.201900108.
  5. Liu, W.; Zuo, H.; Wang, J.; Xue, Q.; Ren, B.; Yang, F. The Production and Application of Hydrogen in Steel Industry. International Journal of Hydrogen Energy 2021, 46 (17), 10548–10569. https://doi.org/10.1016/j.ijhydene.2020.12.123.