The build-out of the hydrogen economy will be facilitated by advances in turbomachinery technology in tandem with the rollout of hydrogen strategies, according to Baker Hughes technology and engineering experts at the company’s annual meeting on Tuesday.

“We see growth of hydrogen over the next few decades as the scale of clean hydrogen makes the production more cost competitive and [via] the adoption of hydrogen into other applications,” says Luke Woodside, engineering manager, Baker Hughes.

“The development of the hydrogen value chain needs some work, and these strategies that are being put in place now will provide a regulatory framework, government incentives and the enhancement of technology. These initiatives will also drive scale to meet demand, which will eventually lead to a viable hydrogen economy.”

Compressor advances

The build-out of the hydrogen economy will depend on the development of supply-side technology. Baker Hughes says a key area of this is turbomachinery and significant advances are in the development pipeline.

“Centrifugal compressors offer the possibility of going towards economy of scale, to a larger plant size and to get benefit of the bigger machine, reduce costs and also maintenance” Baldassarre, Baker Hughes

A key technology for hydrogen is centrifugal compressors, which are essential for the transportation of hydrogen, in high volumes but relatively lower pressures, between production and utilisation in turbines and elsewhere. By contrast, reciprocating compressors are utilised in end-uses such as filling stations with very high pressures, up to 900 bar, but lower volumes per hour.

Centrifugal compressors, particularly, are the focus of Baker Hughes’ R&D. "The transportation portion can have a very important role in terms of capex,” says Leonardo Baldassarre, compressor and pump technology general manager, Baker Hughes.

Standard centrifugal compressors have multiple casting whereas the new generation of high-pressure ratio compressors (HPRCs) can cope with, as the name suggests, higher pressures per casing. “Our future is HPRC,” says Baldassarre.

HPRC compressors have several attributes in their favour, including increased tip speed, increased rotating speed, compressor design optimisation and a reduced number of compressor bodies (perhaps just one, reduced from three), which results in a more compact solution.

HPRCs are up to 50pc smaller and up to 30pc lighter, and have simplified installation, greater reliability and availability, lower downtime and total cost of ownership as well as wide revamping flexibility, according to Baldassarre.

The next generation of HPRCs will incorporate higher strength material, better aerodynamics and an improved machine layout. Further into the future, HPRCs will have a sealed compressor, multiple and magnetic bearings and a high-speed motor.

“The versatility and energy density of hydrogen makes it a great enabler for decarbonisation and the adoption of renewable energies worldwide” Woodside, Baker Hughes

Baldassarre says hydrogen could be compressed for transportation up to 80-90 bar, depending on the downstream use. “It is very important to reduce capex and have a compact solution,” he says.

“Centrifugal compressors offer the possibility of going towards economies of scale, to a larger plant size and to get the benefit of the bigger machine, reduce costs and also maintenance.”

He adds that an efficient way of transporting hydrogen is to blend it into natural gas, which means existing infrastructure can be used after relatively small modifications. Another blending option is to do so in ammonia.

Transporting pure hydrogen “simplifies the way we can use hydrogen downstream” but complicates transportation and makes it more expensive, says Baldassarre, so the distance travelled will be a key consideration.

In 2020, only c.20pc of hydrogen is transported away from the plant before it is used, but “in the future, depending on the location of this plant and utilisation, transportation could play a significant role,” he says.

Growing demand

Countries are setting net-zero targets and hydrogen is widely seen as a critical component in meeting these goals. Thirteen countries have released hydrogen strategies and others are under development. “The EU is setting the precedent by announcing a hydrogen roadmap, which requires all member countries to formulate their own hydrogen strategy,” says Woodside.

“Clean production of hydrogen without emissions of CO₂ is the fuel of the future, and we believe this to be true because the versatility and energy density of hydrogen makes it a great enabler for decarbonisation and the adoption of renewable energies worldwide.”

The IEA has released a sustainable development scenario that is aligned with the Paris Agreement that forecasts the development of hydrogen in a sustainable way over the coming decades.

In 2019, 71mn t of hydrogen was produced and the main consumption is in refinery applications, ammonia and methanol production as well as some other key industrial uses, according to IEA data. By 2050, the IEA expects demand to be 287mn t, spread over a far wider range of end-uses.

287mn t – Hydrogen demand in 2050

Transportation will be a “major player”, says Woodside. “Medium and heavy transport vehicles have some efficiencies over electric vehicles in terms of refuelling times and the overall weight of the vehicle itself.

“A cornerstone of this development plan and the forecast of demand is power generation, where gas turbines and fuel cells will bring renewable energies into peak demand times for consumers.”

Hydrogen is produced almost entirely as brown hydrogen, via the gasification of coal, and grey hydrogen, via steam methane reforming (without carbon capture and storage). Brown hydrogen produces c.19kg of CO₂ per 1kg of hydrogen. Grey hydrogen, the predominant method, produces 10kg of CO₂ per kg of hydrogen.

“Not only our industry needs to be decarbonised, but actually the production of hydrogen itself,” says Woodside. “And one of the ways to decarbonise is to capture and sequester the CO₂ before it is released into the atmosphere… [this is] known as blue hydrogen.”

The cornerstone to the development of this market “is really green hydrogen”, the production of hydrogen via electrolysis using renewable electricity, according to Woodside.

“We agree that blue and green hydrogens will eclipse the production and replace the current sources of brown and grey hydrogen. However, in order for this to happen, we need scale and cost competitiveness.”

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Author: Alastair O’Dell<BR>Senior Editor