CO2 flow loop. Photo: Espen Solli, 2018

FALCON CO2 Flow Loop

Falcon is a closed loop designed to study situations where the CO2 in transport pipelines and injection wells(CCS) enter the two-phase vapour-liquid region. The phase transitions can be due to pressure and/or temperature changes

FALCO2N – IFE’s Flow Assurance Loop for CO2 transport

FALCON during construction; before applying insulation to vessels and pipes and before sheltering the test rig

The test facility contributes with research for safe and cost effective CO2 transport through experimental results used for modelling and validation of pipeline simulators.

The CO2 flow loop is a semi-outdoor test rig designed and built to accommodate test campaigns related to pipeline transport and well injection of pure CO2 or CO2 mixtures. The design and the instrumentation of the test facility serves the main motivation for building the flow loop, emphasizing pipeline flow of CO2 with phase transitions. The schematic shows a schematic of the FALCON test facility. It consists of a test section, a return section, a vapour-liquid separator, a liquid pump, a gas booster and various auxiliary components. The flow rig has a combined heating and cooling system and is well insulated. It also has a unique system for pressurization, consisting of a cylinder w/piston operated by an hydraulic aggregate.

Operational control of the loop is through a fully integrated computer system, which also handles the data acquisition.

Schematic of the FALCON test facility.

Topics that can be studied include:

  • Basic steady state multiphase flow of CO2, measuring pressure drop, holdup and flow regimes in pipelines with inclinations form horizontal to vertical
  • Flow through wellhead chokes with significant pressure drop, Joule-Thomson cooling and phase transition
  • Various shut-in and startup scenarios with heat transfer and phase transition
  • Pipeline and vessel depressurization for pipeline integrity during maintenance operations and unintended pipeline rupture
  • Pressure transients caused by sudden valve closing; fluid hammering

The test facility can also be used for testing of instruments and components.


CO2 flow loop. The test section in vertical position

The CO2 flow loop is currently equipped with the following instrumentation:

  • Gamma densitometers for measurement of vapour-liquid phase fractions
  • dP-transducers for pressure drop measurements
  • Sapphire sight glasses for visual observations
  • High Speed Video camera for capturing transient flow processes
  • Accurate flow meters for measuring inlet conditions
  • Numerous pressure and temperature sensors to monitor the flow conditions

Technical specifications

Loop material: AISI 316
Fluids : Pure CO2 and CO  w/impurities, e.g.N2, CH4, H2, O2
Pressure:  Max. 150 bara
Temperature range: -150oC to +50°C
Test section:  ID 44 mm, L= 13 m
Test pipe incl.  + 7 deg. + vertical
Superficial vapour velocity range: 0 – 10 m/s (55 Am3/h)
Superficial liquid velocity range:   0 – 3 m/s (15 Am3/h)


Equipment for pressurization and pressure control of the test rig
Test section in horizontal position (before heat exchanger and insulation were mounted)
CO2 flow loop, field test on the dispersion of CO2 from a simulated pipe rupture


Langsholt, Morten

Flow Technology,

Related articles