The Northern Territory Government is working to develop a carbon capture, utilisation and storage (CCUS) hub at Middle Arm. Here we discuss the project, how CCUS works and what pumps are used in the process.
As one of the world’s largest carbon emitters per capita, Australia faces the challenge of reducing greenhouse gas emissions while still relying on fossil fuels for its energy needs.
Carbon capture and storage (CCS) is an emissions reduction technology that could have the potential to help mitigate climate change by preventing greenhouse gases from contributing to global warming.
CCS is the process of capturing carbon dioxide (CO2) emissions and storing it deep underground to prevent its release into the atmosphere. Utilisation involves turning that carbon, which would otherwise be waste, into feedstock for another industry or purpose.
Pump technology plays a vital role throughout the CCUS process, and is utilised to facilitate the movement, compression and injection of CO2 during CCS activities. As CCUS projects continue to develop, the pump industry will play a crucial role in ensuring the safe and efficient operation of CCUS systems.
Middle Arm Sustainable Development Precinct
The proposed CCUS hub at the Middle Arm Sustainable Development Precinct will be one of the largest facilities of its kind in the world.
Once carbon is captured and transported to the hub, it will either be stored or used. Storage at the precinct will entail carbon being sent via a pipeline to geological storage outside of Darwin.
There will also be opportunity for industries to utilise carbon captured at Middle Arm to produce other valuable products. The Northern Territory Government is working in partnership with the CSIRO, industry and engineering companies to develop a business case to map a pathway for establishing CCUS at Middle Arm.
The State Government said the hub is intended to enable existing liquefied natural gas (LNG) production to expand while creating a lower carbon footprint, as well as establish new lowemission hydrocarbon and hydrogen based industries
Northern Territory Chief Minister, Natasha Fyles, said, “The Territory is rapidly emerging as a key player when it comes to the global supply chains, and new technologies needed for energy transition. “We have always said the core component of the Middle Arm development is sustainability and will include renewable energy.
We are creating new jobs for Territorians in existing and emerging sectors, including low emissions energy, advanced manufacturing, and low-emissions minerals processing. “The creation of a carbon capture and storage industry in the Territory will allow us to develop more projects as we work towards clean, green energy.”
With CCS gaining momentum, there is a greater need for reliable, energy-efficient pump technologies that can handle the unique challenges of CO2 transportation and injection.
Pumps and CCS
Due to the similarities between fossil fuel extraction and CCS, pumps used to inject natural gas liquids (NGL) into production fields (centrifugal pumps) and inject acid gas liquid back into the fields (high pressure pumps) can be applied to CCS activities.
Multistage pumps and hydraulic power recovery turbines can also be used in CCS processes at refineries, and petrochemical and chemical manufacturing plants. CCS also encompasses a range of other pump-related equipment such as boilers, compressors, blowers and turbines.
In the capture phase, CO2 is separated and captured in a gas or exhaust stream. This can be achieved through precombustion, post combustion, or oxyfuel methods. Pumps are employed to handle the movement of gases and facilitate the separation of CO2.
Specifically, they help to maintain appropriate flow rates and pressures during processes such as absorption, stripping, and membrane separation. Both single and multistage pumps can be used, depending on the application.
Upon capture, the CO2 must be compressed to higher pressures for transportation and injection. Compression pumps, including centrifugal or reciprocating compressors, are often employed to increase the pressure of CO2. These pumps ensure that the CO2 is efficiently compressed for costeffective transportation via pipelines or other means.
The compressed CO2 is then transported from the capture site to the storage site. Pumps play an important role in this phase, providing the required pressure to overcome friction and transport the CO2 efficiently over long distances. Pump stations are placed strategically along the pipeline route to maintain pressure levels and regulate the flow of CO2.
Once the CO2 reaches the storage site, pumps are used for the injection process. Injection pumps provide the pressure necessary to safely inject the CO2 deep underground into suitable geological formations. The selection and design of pumps in CCS projects are critical to ensuring efficient and reliable operations.
Factors such as flow rates, pressure requirements, temperature, and the properties of the CO2 stream must be considered when choosing the right technology. Additionally, pump systems in CCS need to be carefully designed and maintained to minimise leakage and ensure the safe and secure storage of the CO2 underground.
Unlocking the potential
Northern Territory Minister for Mining and Industry, Nicole Manison, said CCS is vital to achieving net zero emissions. “The State Government is working with CSIRO, INPEX, Santos and other big industry players to establish a carbon capture and storage common-user hub at Middle Arm.
“We are making sure we are creating an industry that will be able to provide crucial energy security to Australia and the region, into the future,” Ms Manison said. The Northern Territory’s existing LNG industry, export links with the Asia-Pacific region and high renewable electricity potential mean it is well positioned to create valuable CO2-derived products and support industry’s decarbonisation efforts.
A recent report by CSIRO highlights the opportunity for CO2 utilisation to support low-emission manufacturing in the Northern Territory, as part of the Northern Territory Low Emission Hub business case. According to the report, the Northern Territory could turn waste carbon dioxide into commodity products by integrating CO2 utilisation technologies into local hub developments.
CSIRO Oil and Gas Researcher, Dr Andrew Ross, said, “The potential near and long-term role of carbon capture and utilisation within a Northern Territory Low Emission Hub is an important input to understanding the interaction between different industries in the context of a low emissions industrial ecosystem.”
There are opportunities to manufacture methanol, jet fuel, urea, methane and mineral carbonates in the Northern Territory using captured CO2. Urea is a compound with a high nitrogen content and is commonly used in fertilisers, although it is also used for resins and glue, fuel additive Adblue, medical and cosmetic products and fire extinguishers.
While Australia imports the vast majority of the urea it requires, the precinct offers the opportunity to make urea using CO2 waste from other industries. Another example of carbon utilisation is cement manufacturers developing technologies to inject carbon into their manufacturing process. This improves product performance and offsets emissions.
Development of a hub with shared CCUS and hydrogen production infrastructure can support the deployment and scale-up of CO2 utilisation opportunities.
Limitations of CCS
The large-scale CO2 storage hub could support the development of low emissions industries, benefit manufacturing industries, and have the potential for a significant emissions management hub beyond the Northern Territory, including South-East Asia.
However, the CCS is not a substitute for clean energy sources such as wind, solar and pumped hydro. While CCS can only address emissions from specific sources, clean energy sources provide a long-term solution to reduce emissions across numerous sectors.
In addition, the CCS process is not foolproof. It carries the potential risks of leakage or accidental release, which can have a significant environmental impact.
Successfully mitigating climate change will require a reduction in reliance on fossil fuels and widespread adoption of clean energy sources. CCS should play a complementary role as Australia transitions away from gas and coal.
