Decarbonisation Technology - May 2024 Issue

Post-combustion ue gas

Location

A B

Temperature

35 ˚C

25 ˚C 1.4 barg 0.6 bara

150 ˚C 0.2 barg 0.2 bara

Pressure 25 barg CO partial pressure 3.4 bara

H concentration* N concentration* CO concentration* CO concentration* HO concentration* CH concentration* O concentration*

76 % 1 % 5 % 0 % 3 % 0 % 15 %

27 % 1 % 15 % 0 % 10 % 0 % 47 %

0 % 62 % 5 % 17 % 20 %

Steam

Water

Heat

Waste heat recovery

0 % 1 %

Steam

Boiler

*Molar

Fired heater

PSA H purification

Compressor

Natural gas feedstock

Water gas shift

Hydrogen for desulphurisation

Pre-former

High temp.

Low temp.

Desulphurisation

Reformer

Natural gas for burner

PSA tailgas

Burner air

Location A

Location B

Location C

Process stage Advantages

Pre-PSA High pressure, high CO concentration, highest CO partial pressure, lowest unit cost of CO capture from amine solvent or VSA processes

Post-PSA Low ow rate (H removed), highest CO concentration

Post-combustion More than 90% capture rate possible (captures process CO and burner CO emissions), low pressure location can be suitable for emerging CO capture techno- logies such as TSA and mineralisation Low pressure, lowest CO concentration, high ow rate due to combustion air, highest unit cost of CO capture from amine solvent or VSA processes

Disadvantages

Max 70% CO capture rate possible (burner CO emissions not captured), high ow rate (H included)

Max 70% CO capture rate possible (burner CO emissions not captured), low pressure

Figure 1 Potential locations for CO 2 capture from steam methane reforming

required to achieve the necessary CO 2 intensity of hydrogen production (Location C in Figure 1). Low-carbon ammonia cracking and import Blue ammonia may be produced at low cost in the US Gulf Coast, where natural gas prices are low and CO 2 storage can be achieved in locations close by, such as the Permian Basin. Linde and OCI will collaborate to produce 1,100,000 million tonnes per year of blue ammonia. Partial oxidation (POx) will be used to convert natural gas to syngas. The process operates at high pressure which reduces the pre-combustion CO 2 capture costs. CO 2 liberated during hydrogen production will be captured and sequestered. The added cost for carbon capture and storage (CCS) is around $120 per tonne of ammonia. This covers the additional equipment and energy costs to remove the CO 2 from the gas stream, transport it to a sequestration location, and inject it for permanent storage. Many projects have proposed to produce green hydrogen at scale. The optimal locations are where there is abundant renewable power

generation potential from integrated wind and solar schemes, such as Western Australia. In the future, when electrolyser costs reduce and the efficiency of this technology improves, the cost of green hydrogen in these locations could potentially be comparable to blue hydrogen. Shipping and terminal infrastructure must be developed to connect the blue and green hydrogen producers with energy markets. Air Products is also planning to make clean hydrogen available in Western Europe from cracked green or blue ammonia. The ammonia will be imported through the ports of Rotterdam and Hamburg. In Hamburg, Air Products will construct a new ammonia terminal for this purpose. At Rotterdam, Air Products has partnered with Gunvor to develop the import terminal. In Hamburg, Mabanaft will partner with Air Products. In addition to the potential to crack ammonia to make hydrogen, low-carbon ammonia can be fired directly to generate steam in boilers or power on specially constructed gas turbines. On a smaller scale, it will also see application