Brief summary of the CLIMIT Demo project “Technology qualification of low-pressure CO₂ ship transportation”

The project has a total budget of NOK 26 million and was awarded 32% funding of the cost budget by CLIMIT Demo in 2021.

LP transport is an unproven solution

Today, CO₂ is transported in liquid form on ships with pressures and temperatures around 15 barg and -25 degrees Celsius, which is referred to as medium-pressure (MP). At the same time, the project’s partners believe there may be advantages to using lower pressures for transporting larger volumes of CO₂ by ship. The pressure/temperature range in question is 6 barg and -50 degrees Celsius, and referred to as low-pressure (LP). The potential advantage of LP transport is that lower pressures allow for larger tanks and ships to be built, which in turn would lead to a lower per-tonne cost of cargo capacity for LP ships than MP ships.

LP transport is an unproven solution with higher risks than MP transport. LP pressures and temperatures are closer to the triple point for CO₂ than MP. The triple point is the point at which the three phases of the substance are in equilibrium, solid (dry ice), liquid and gas. LP transport thus has lower margins compared to MP when it comes to unwanted phase changes, something which entails a technical risk that must be defined and minimised through good process design in the transport chain. The project partnership aims to qualify LP transport in order to be able to use this solution in future phases of Northern Lights and other future CCS chains that need to transport large volumes of CO₂.

Main activities

The project will be carried out in accordance with the DNV’s recommended practice, ‘DNV GL RP-A203 Technology Qualification’, and consists of two main activities:

1) Designing ships with a cargo capacity of 30 kilotonnes, loading system (tanker loading/unloading system), and plants to liquify CO₂.

2) Simulation and experimental testing: Development of loading/unloading process simulation tools (better definition of risk of dry ice formation), and experimental testing around the triple point as a basis for setting safety margins.

The intention behind the project is to reduce the risks associated with LP transport, and the goal of the project is to qualify LP transport for use in future CCS chains.