*Article* **Influence of Pressure on Gas**/**Liquid Interfacial Area in a Tray Column**

#### **Adel Almoslh \*, Falah Alobaid, Christian Heinze and Bernd Epple**

Institut Energiesysteme und Energietechnik, Technische Universität Darmstadt, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany; falah.alobaid@tu-darmstadt.de (F.A.); christian.heinze@tu-darmstadt.de (C.H.); bernd.epple@tu-darmstadt.de (B.E.)

**\*** Correspondence: adel.almoslh@tu-darmstadt.de; Tel.: +49-6151/16-23004; Fax: +49-(0)-6151/16-22690

Received: 28 May 2020; Accepted: 1 July 2020; Published: 3 July 2020

**Abstract:** The influence of pressure on the gas/liquid interfacial area is investigated in the pressure range of 0.2–0.3 MPa by using a tray column test rig. A simulated waste gas, which consisted of 30% CO2 and 70% air, was used in this study. Distilled water was employed as an absorbent. The temperature of the inlet water was 19 ◦C. The inlet volumetric flow rate of water was 0.17 m<sup>3</sup>/h. Two series of experiments were performed; the first series was performed at inlet gas flow rate 15 Nm<sup>3</sup>/h, whereas the second series was at 20 Nm<sup>3</sup>/h of inlet gas flow rate. The results showed that the gas/liquid interfacial area decreases when the total pressure is increased. The effect of pressure on the gas/liquid interfacial area at high inlet volumetric gas flow rates is more significant than at low inlet volumetric gas flow rates. The authors studied the effect of decreasing the interfacial area on the performance of a tray column for CO2 capture.

**Keywords:** CO2 capture; CO2 absorption; process simulation; validation study; experimental study
