Decarbonisation Technology - February 2025 Issue

Notes: – CO emissions are also associated with the energy and power requirements for this industry sector – These can potentially be decarbonised with renewable power and electrical heating or microwaves – CCS to capture CO from the process and/or the associated energy production is possible

Steam methane reformer

Aluminium smelting

Calciner tower & clinker kiln

Blast furnace

Oil rening

Aluminium smelting Cement making

Iron making

Hydrogen production from methane reforming for fuels desulphurisation CH + HO CO + 3H CO + HO CO + H Use turquoise hydrogen or green hydrogen to avoid the reforming reaction; or As above using renewable methane feed the reformer with biomethane instead of natural gas

Reduction of iron ore to iron using coke

Reduction of limestone to calcium oxide CaCO CaO + CO Replace a portion of the limestone with alternative materials such as calcined clay to make clinker for cement Above reaction can only partially be avoided

Reduction of alumina to aluminium using graphite electrodes

Application that releases CO

2FeO + 3C 4Fe + 3CO FeO + 3CO 2Fe + 3CO Use hydrogen instead of coke; or substitute coke with carbon from turquoise hydrogen production As above using renewable carbon, or use hydrogen: FeO + 3H 2Fe + 3HO None

2AlO + 3C 4Al + 3CO

Chemical reaction producing CO Decarbonisation approach for CO generated by the process

As above using renewable graphite electrodes carbon from fossil fuels to make the electrodes Gold and silver rening, electric arc furnace to melt scrap steel Use carbon from turquoise hydrogen production instead of

Reactions for the decarbonised process

– Lime making, as above

Other industries with similar applications

Ammonia, urea, methanol, gas-to-liquids

– Refractory materials; MgCO MgO + CO – Glass making NaCO, CaCO, MgCO

Figure 3 Difficult-to-decarbonise industries – CO₂ is released from within the process

and refinery operations. Policymakers must recognise the benefits of hydrogen with any degree of reduced CO₂ intensity. The current criteria for ‘blue’ hydrogen are tight, and if a decarbonisation initiative does not get the ‘blue’ badge, the case is weak. CO₂ intensity must be a sliding scale The ‘blue’ hydrogen benchmark is relevant for new-build projects based on autothermal reformers (ATRs) or gas heated reformers (GHRs) with built-in CCS, but 2,000 SMRs operating today can be decarbonised with CO₂ capture equipment retrofits. This is 2025, and in many parts of the world, there has been significantly less progress towards declared net-zero targets than has been promised. ‘More of the same’ will not help us achieve 1.5°C and is unlikely to cap climate change at 2 or 3°C. We

need high-impact action now – ideas that can rapidly and cost-effectively be deployed. The costs and scalability of green, blue, or hydrogen of any degree of CO₂ intensity must be seen in the context of alternative industrial decarbonisation measures. The idea of a hydrogen project going for ‘green, blue, or broke’ has resulted in failed business cases and inhibited meaningful progress. CO₂ intensity is what matters. Every reduction in GHG emissions is beneficial. Making a rapid impact means there is no room for the perfect to be the enemy of the good. We must accept that the next 30 years will be about rapid decarbonisation of existing infrastructure in addition to progressive development and deployment of ultra-clean technology. There must be support for GHG emissions reduction in all forms rather than CO₂ intensity thresholds, which indirectly promote some technologies above others.