Nov-2024

The energy transition: At the heart of the matter

The outlook on energy transition is challenging to say the very least. It is important to explore what flow control technologies can bring to the table to address the many pressing challenges that must be faced.

Andreas Pischke and Piotr Kulisz
Valmet

Article Summary

Valve solutions have a vital role in many crucial applications such as sustainable aviation fuel (SAF) production, carbon capture, utilisation and storage (CCUS), hydrogen, and plastics liquefaction – all segments which are directly contributing towards cutting carbon footprint and curbing global warming. Piotr Kulisz and Andreas Pischke, Valmet Flow Control business line, explore the critical role of flow control technologies in the energy transition.

International Renewable Energy Agency (IRENA) reporting states that limiting global warming to 1.5°C requires cutting carbon dioxide (CO₂) emissions by around 37 gigatonnes (Gt) from 2022 levels and achieving net-zero emissions in the energy sector by 2050. This in itself is a huge task.

A 1.5°C compatible pathway requires an urgent and wholescale transformation of the way societies consume and produce energy. Global investments across all energy  transition technologies reached a record high of US$1.3 trillion in 2022, yet fossil fuel capital investments were almost twice those of renewable energy investments. Consequently, it is imperative that the oil and gas, refining and chemical industry work hard and fast towards climate sustainable operations.

Technology companies are stepping up
In supporting this endeavour, despite current challenges, leading technology companies have established R&D programmes, where along with their ecosystems, they can come together to innovate, renew and aid their customer industries in the shift to carbon neutrality.

Circularity is at the core of these programmes and targets are closely connected to achieving a carbon neutral future. The following part of this article will focus on flow control technologies that enable the SAF, CCUS, hydrogen, and plastics liquefaction segments to contribute towards this objective.

Battling sky-high aviation emissions
While electric vehicles are expected to dominate road transport and methanol marine transport, the aviation sector holds the most promise for bio-refining and the subsequent shift to SAF. In 2022, IATA estimated global SAF production at approximately 300 – 450 million litres (l) (approximately 0.15% of total global jet fuel consumption. By 2030 it is projected to reach 30 billion l/y and further to 449 billion l/y by 2050 i.e. around 65% of the total global jet fuel consumption.

Turning waste into jet fuel
There are currently nine certified production pathways to produce SAF and many of them include processing units similar to conventional refining – for example hydro-treating, hydro-cracking, isomerisation, and fractionation.

Diverse feedstocks including biomass, vegetable oils, animal fats and used cooking oils bring their own challenges to valves. Valves with special alloys and hard facing and firesafe designs are required to ensure safe and uninterrupted performance.

Dehydration is an integral part of some of these processes. To secure long term reliability, metal-seated ball valves with unique closed and scraping seat designs and high cycle actuators, coupled with high-capacity intelligent controllers, are strongly  recommended. Triple-offset eccentric disc valves with metal seats protected from the shear force of the process fluid and mechanically induced tightness can also be a viable option.

Capturing new opportunities
Flow control and high-quality valves also play an important role in modern carbon capture technologies. Each process to separate CO₂ has its own set of challenges whether for post- and pre combustion or oxyfuel combustion. Low temperature challenges occurring in cryogenic separation require an additional focus on valve design and material selection.

New but field proven application-based solutions
Many of the CO₂-removal processes are known and have been applied for decades in the refinery industry, whether for production of hydrogen by steam methane reforming or for ethylene production by steam cracking.

The widespread amine-based absorption with its amine regeneration units also presents valves with challenges such as corrosion, high temperatures and pressures. High concentrations of H₂S and CO₂ require material selection according to NACE. Depending on the absorber pressure, the pressure drop across the valve can reach up to 170 bar. Two phase flow, flashing or outgassing can be expected in this application.

Performance in severe service
Severe service control valves incorporating anti cavitation trims, either multi-stage disc stacks or self- flushing Q-trims have proven effectiveness in noise attenuation at source. Utilisation of evolving 3D printing technologies will allow these capabilities to be enhanced. At the same time, angle pattern globe valves or flow- to-open eccentric plug valves have been proven in flashing service.

Swing adsorption technologies mainly used to purify hydrogen in refineries now get more attention also in purifying carbon dioxide instead of releasing it straight into the atmosphere – but rather preparing it for further utilisation.

Pressure swing adsorption (PSA) requires highly reliable switching valves to remain gas-tight after hundreds of thousands of cycles at pressures of up to 100 bar. Valves in thermal swing adsorption (TSA) see temperatures of up to 400°C during the adsorbent regeneration phase and must be capable of maintaining the same tightness under these conditions. High performance butterfly and ball valves have been proven in use in thousands of PSA and TSA operations around the world.

New approaches in every turn
Half of the carbon emissions in a refinery come from the production, with the other half from power generation. This requires new carbon dioxide capture systems that separate the carbon dioxide from the flue gases of heating systems powered by fossil fuels or, in the case of gas turbines, from the exhaust gases of the turbines. Next to amine-based absorption there might be other technologies applied, such as oxyfuel combustion or pre-combustion technologies. Cryogenic separation should also not be forgotten, which makes sense where the CO₂ is needed in liquefied state.