Influence of water-film-forming-unit on the enhanced removal of carbon dioxide from mixed gas using water absorption apparatus

This research uses tap water to absorb carbon dioxide from mixed gas (N₂ and CO₂) in an absorption apparatus coupled with a water-film-forming-unit (WFFU). The objective is to assess the benefits of using a WFFU to enhance CO₂ removal efficiency at low pressure conditions. Based on our results, the WFFU significantly improves CO₂ capture at 0.30 MPa in a water absorption system with two WFFUs. The CO₂ removal efficiency was 20% greater than for systems without WFFUs. Moreover, statistical data attained by the Taguchi analysis method showed that the number of WFFUs used in the absorption system has the greatest influence on CO₂ removal efficiency (contribution percentage = 50.65%) compared to gas pressure, initial CO₂ concentration, gas-to-liquid ratio, and liquid temperature. We also thoroughly investigated the effects of these factors on CO₂ removal performance. The optimum conditions for CO₂ removal efficiency in a system equipped with two WFFUs are low temperature, low gas-to-liquid ratio, low gas pressure (0.25–0.30 MPa), and high inlet CO₂ concentration. These findings could provide an effective method for capturing CO₂ from exhaust gases, and thus help mitigate global warming.