Suitability of different twin-fluid atomizer types for CO2 capture in spray columns

article in a collection out of WoS and Scopus

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Post-combustion-capture of primary greenhouse gases is one of the global warming reduction methods. Twin-fluid atomizers can be used for spraying of aqueous ammonia solutions, which scrub CO2 from flue gasses. This process requires well-tailored spray characteristics, such as mean drop size, drop size distribution and droplet density. Spray cone angle (SCA), and droplet velocity are additionally relevant in spray mixing and droplet-gas interactions in spray columns. Choosing a relevant atomizer and optimum operation regime allow for effective solvent utilization in the flue gas scrubbing process. The present work examines four different twin-fluid atomizers operated at an inlet pressure of 0.05, 0.1 and 0.2 MPa with gas-to-liquid ratio (GLR) 2.5, 5 and 10%: classic effervescent atomizer with single exit orifice, multi-hole effervescent atomizer with four exit orifices and two novel “impinging” effervescent atomizers with impingement angles of 20° and 45°. Their spray structure and SCA were analysed using high-speed visualisations. The droplet size and velocity in the spray were probed using a phase-Doppler analyser (PDA). Impinging effervescent atomizers shows favourable spray characteristics for spray columns application as smaller RSF, uniform velocity and larger spray cone angle.

Post-combustion-capture of primary greenhouse gases is one of the global warming reduction methods. Twin-fluid atomizers can be used for spraying of aqueous ammonia solutions, which scrub CO2 from flue gasses. This process requires well-tailored spray characteristics, such as mean drop size, drop size distribution and droplet density. Spray cone angle (SCA), and droplet velocity are additionally relevant in spray mixing and droplet-gas interactions in spray columns. Choosing a relevant atomizer and optimum operation regime allow for effective solvent utilization in the flue gas scrubbing process. The present work examines four different twin-fluid atomizers operated at an inlet pressure of 0.05, 0.1 and 0.2 MPa with gas-to-liquid ratio (GLR) 2.5, 5 and 10%: classic effervescent atomizer with single exit orifice, multi-hole effervescent atomizer with four exit orifices and two novel “impinging” effervescent atomizers with impingement angles of 20° and 45°. Their spray structure and SCA were analysed using high-speed visualisations. The droplet size and velocity in the spray were probed using a phase-Doppler analyser (PDA). Impinging effervescent atomizers shows favourable spray characteristics for spray columns application as smaller RSF, uniform velocity and larger spray cone angle.

CO2 capture; Twin-fluid atomizers; Phase-Doppler anemometry; Spray characteristics

02.09.2021

ICLASS 2021 - 15th Triennial International Conference on Liquid Atomization and Spray Systems

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