Gas-lift circulation of a liquid between two inter-connected bubble columns. (8th June 2020)

• Record Type: Journal Article
• Authors: Jafarian, Mehdi; Chisti, Yusuf; Nathan, Graham J.
• Is Part Of: Chemical engineering science. Volume 218(2020)
• Publication Date: 2020-06-08
• Subjects: Airlift reactor -- Bubble column -- Chemical looping -- Two-phase flow -- Gas holdup; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2020.115574
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: A novel two-column gas-lift reactor configuration was developed. Reactor comprised two interconnected riser zones forming an α-shaped loop. Mixing and circulation were achieved solely by a gas-lift action. Possible applications in chemical looping with different gases in the two columns. Correlations were developed for gas holdup and liquid circulation rate. Abstract: A pneumatically-mixed novel configuration of two inter-connected bubble column reactors is reported using air-water to demonstrate the device, enabling circulation of a liquid between the columns solely by a gas-lift mechanism. The new reactor may be used for circulating a high temperature/corrosive liquid between the columns, enabling the cyclical processing of a liquid medium with two different gaseous reactants. The effects of superficial gas velocity, unaerated liquid height in the columns and the diameter of aeration nozzles are discussed with reference to the gas holdup in, and rate of liquid circulation between, the two columns, together with the energetics of circulation. The height of the gas-free liquid in the reactor was found to influence the liquid circulation velocity positively, but the effect of aeration nozzles diameter was marginal. The lowest and highest measured flow rates of circulating water between the columns were 0.7 dm 3 min −1 and 4.2 dm 3 min −1, respectively.