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As discussed in our recent writing there is an array of ‘colors’ or types of hydrogen production; some more established, and most under development. They all function based on converting a hydrogen-containing molecule into H2 gas, which can then be combusted, emitting only water, given that flame temperatures are within a certain threshold. 

Grey hydrogen, steam methane reforming(SMR), splits methane into H2 and CO2. This is the most common and the cheapest of all hydrogen production methods, but it has the harshest ecological footprint. Green hydrogen, using renewable energy to split water molecules into (hydrolysis), is still under development for large-scale use, but it’s quickly growing. It has the smallest ecological footprint of the H2 production methods, but it is currently the most expensive given its dependence upon renewable energy.

Concrete production is an energy intensive industry with a heavy ecological footprint and it is the second most used resource only behind water. Cement is concrete’s main binding component and its production is the most problematic part of concrete manufacture. Cement is responsible for 6-8% of all human-made CO2 emissions due its chemical reaction and its need for high heat, mainly supplied by fossil fuels(often called process emissions vs. fossil fuel emissions). So we might wonder where and how hydrogen fuel can play a role in cement production and if it can be a key driver in decarbonization of the industry.

It seems there is great potential for hydrogen fuel to reach these goals, but there are some barriers that need addressing. H2, the molecule of hydrogen fuel, is a gas at room temperature and it is very light, occupying a large volume, giving it a lesser amount of energy per given volume; it has low energy density compared to other fuel sources. This quality is a main hurdle in hydrogen production, transportation, storage, and therefore a hurdle in creating infrastructure to drive adoption and scaling. H2 gas must be stored and transported under high pressure to minimize the space it occupies, therefore the infrastructure is more specialized and more costly than traditional fuel pipelines–10 to 50% more according to a report by IRENA. They also state that renewable ‘green’ hydrogen production is overall two to three times more expensive than fossil fuels based on current systems. 

The high costs of green hydrogen are based on lagging policy, the lack of major infrastructure, and therefore lack of a stable market. Cemex, an international cement company, states some of their hurdles in adopting hydrogen fuel tech after investing in a hydrogen fuel startup. In addition to the barriers mentioned here, they point to the extra safety and regulatory measures needed for the highly flammable and potentially explosive gas. 

Cement production requires a fine tuned mixture of material inputs that are adapted to materials available in the region surrounding the cement plant. Therefore, each cement plant across the world has slight technical differences, with varying components, processes, and layouts. The fuel source for heating cement production also varies depending on local availability, so a universal plug-and-go attempt to implement the use of hydrogen fuel requires location specific specialization, or a method that can easily adapt to each plant’s differences. These site-specific differences also create regulational challenges for cement, since most regions have differing production regulations and will have to adjust accordingly with new technology. Other industries with more globally consistent production methods like steel have more universal production methods and therefore more globalized regulations, that allow for more adaptation to large-scale technology change.

Cement is also a relatively cheap material that costs about $130/ton in the US, but it also emits about 0.58 tons of CO2 per ton of cement produced. A 2019 feasibility analysis in the UK by Cinar LTD, MPA, and VDZ modeled an alternative fuel cement production scenario based on a mixture of H2, biomass, and plasma(electrification) as fuel. They stated that the model supported the possibility of removing all fossil fuel emissions, leaving only process emissions(their statement does, however, ignore combustion emissions from biomass, which they claim is “considered to be CO2 neutral”). Their model estimated that each ton of CO2 saved cost about $90 and the total cost increase of clinker for fuel switching was about $28/ton. Those premiums would be difficult to factor into cement’s low price, but despite these hurdles, the increasing cost of industrial emissions is looming, and many companies are taking steps in the right direction. 

We will discuss those initiatives further in our next article. Thank you for reading.