Effect of atomizer performance on CO2 capture efficiency in spray tower: Pressure swirl and Effervescent atomizers

article in a collection out of WoS and Scopus

en

CO2 is one of the most severe greenhouse gases released into the atmosphere and is responsible for the global increase in temperature. The amount of CO2 released can be reduced by using post-combustion CO2 capture. Spray columns, as simple gas cleaning contractors, can utilize different types of atomizers, e.g. pressure atomizers, twin fluid atomizers and shower head atomizers. The CO2 capture process requires well-tailored spray characteristics, such as suitable mean drop sizes and drop size distribution, droplet density, spray cone angle (SCA) and droplet velocity. Small droplets can be carried away by ambient flow and cause significant sorbent losses, while large ones have small surface area, which determines the rate of mass transfer of CO2. This paper compares pressure-swirl and effervescent atomizers operated at a constant solvent flow rate of 140 kg/h. To change liquid pressure, atomizers scale was changed. Spray droplet sizes were probed using a high-resolution shadowgraph sizer. Absorption tests were carried out on a laboratory-scale spray tower, with diameter 0.2 m and height 2.5 m. The absorption liquid was a 30% MEA solution by weight, and the simulated flue gas contained 10% CO2. The absorption efficiency systematically increased with reduction of Sauter mean diameter (D32). However, effervescent atomizers provided slightly higher absorption efficiency for sprays with similar D32 due to large amount of small droplets, but with much higher energy consumption.

CO2 is one of the most severe greenhouse gases released into the atmosphere and is responsible for the global increase in temperature. The amount of CO2 released can be reduced by using post-combustion CO2 capture. Spray columns, as simple gas cleaning contractors, can utilize different types of atomizers, e.g. pressure atomizers, twin fluid atomizers and shower head atomizers. The CO2 capture process requires well-tailored spray characteristics, such as suitable mean drop sizes and drop size distribution, droplet density, spray cone angle (SCA) and droplet velocity. Small droplets can be carried away by ambient flow and cause significant sorbent losses, while large ones have small surface area, which determines the rate of mass transfer of CO2. This paper compares pressure-swirl and effervescent atomizers operated at a constant solvent flow rate of 140 kg/h. To change liquid pressure, atomizers scale was changed. Spray droplet sizes were probed using a high-resolution shadowgraph sizer. Absorption tests were carried out on a laboratory-scale spray tower, with diameter 0.2 m and height 2.5 m. The absorption liquid was a 30% MEA solution by weight, and the simulated flue gas contained 10% CO2. The absorption efficiency systematically increased with reduction of Sauter mean diameter (D32). However, effervescent atomizers provided slightly higher absorption efficiency for sprays with similar D32 due to large amount of small droplets, but with much higher energy consumption.

Pressure-swirl, effervescent, spray column, CO2, capture,

23.06.2024

ICLASS

Shanghai

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