CO2 storage in the North Sea

To achieve the climate objective of reducing greenhouse gas emissions by 55% in 2030 compared to 1990, industry will also have to take their responsibility. New fuels can make a significant contribution to this, but also the capture and storage of  CO2 (Carbon Capture and Storage, CCS for short).

Project Porthos is a good example of this. Porthos, a joint venture between EBN, Gasunie and the Port of Rotterdam, a project in which CO2 from industry in the port of Rotterdam will be transported and stored in empty gas fields under the North Sea.

After the final investment decision was made in October 2023, construction of the transport pipeline could start in early 2024 in the area of Rozenburg. The pipeline running through the Rotterdam port area is approximately 30 kilometers and then goes some 20 kilometers into the North Sea. The aim is to have the system operational by mid-2026. Thanks to Porthos, the CO2 storage will reduce emissions from the companies in the port of Rotterdam by 10%.

Companies from the Port of Rotterdam, supply their CO2  to a pipeline, that runs through the Rotterdam port area. The CO2 will then be pressurised in a compressor station. The CO2 will be transported through an offshore pipeline to a platform in the North Sea, approximately 20 km off the coast.  From the platform, the CO2 will be pumped into an empty gas field. These gas fields are situated in a sealed reservoir of porous sandstone about 4 kilometers below the North Sea. Porthos will store around 37 Mton CO2, approximately 2.5 Mton CO2 per year, for 15 years.

The CO2 pressed into the wells via the platform, must of course be measured. For this purpose, KROHNE supplies 6 units of OPTIMASS 6400 Coriolis mass flowmeters. The challenge of measuring CO2 , is how to maintain the process conditions stable. CO2 has different phases and is sensitive for the combination of pressure and temperature. If the pressure increases, the phase will change from gas to liquid. Once the CO2 passes the measurement section and enters into the ground, the phase is no longer important. Major advantage of the Coriolis mass flow meter is: the meter can measure multi-phases, an important parameter within this project.

OPTIMASS 6400 Highlights:

• Coriolis mass flowmeter with twin bent tube for liquid and gas applications

• Advanced Entrained Gas Management (EGM): No loss of measurement signal up to 100% gas entrainment in the medium

• For high temperatures up to +400°C as well as cryogenic applications down to -200°C

• Transmitter with advanced instrument and process diagnostics, according to NAMUR NE 107