Inside and outside flow from pipes containing a dense CO2 mixture incorporating impurities : experimental set-up and first results

Abstract : Within the frame of the European project CO2Quest [1,2], medium-scale experiments are underway involving high pressure releases of CO2 containing a range of impurities such as those potentially left from a capturing operation. A dedicated experimental rig was developed so as to investigate the influence of those impurities on the flow inside and outside the pipe. The setup (Figure 1) includes a 37.5 m long 50 mm i.d. pipeline equipped with several sets of pressure and temperature transducers placed along the tube each12 meters. Outside, the “expansion zone” of the jet is specifically instrumented with pressure transducers and thermocouples. The pipe is insulated, and equipped with a mixing system. The latter is basically a pump recirculating the mixture and the impurities are injected in the loop. The mixture is pumped at one end and reinjected at several locations. The composition of the mixture is controlled by sampling and gas chromatography. The chosen impurities are nitrogen and methane and were compressed and inside a bottle and connected in series on the loop. The pipe is supported by 6 masts equipped with electronic weighing devices so as to measure the leakage mass flowrate. A calibrated orifice is placed at one end to allow some variations of this flowrate. A transparent section is provided at mid-length to follow the evolution of the flow (liquid, two phase,..). Films were made.