Search Results (3)

Traditional alkanolamine absorption methods for CO₂ capture suffer from significant absorbent loss and high regeneration energy consumption. To address this issue, novel blended alkanolamine formulations based on monoethanolamine (MEA), methyldiethanolamine (MDEA) and 2–amino–2–methyl–1–propanol (AMP) were investigated. Based on the optimization of CO₂ absorption conditions, a low–temperature and high–efficiency microwave heating desorption method for CO₂ was proposed, and the microwave heating desorption process of a CO₂ alkanolamine absorption solution was optimized. The results show that when the mass ratio of monoethanolamine (MEA), methyldiethanolamine (MDEA) and 2–amino–2-methyl–1–propanol (AMP) was 4:5:1, the composite alkanolamine solution with a concentration of 20% had the best absorption effect at an absorption temperature of 30 °C. The desorption efficiency of this group of formulations at 95 °C reached 89% in 4 min. Compared with the traditional heating desorption method, the CO₂ desorption rate of the microwave heating method at 95 °C increased by 62%, the desorption time was significantly shortened, and the energy consumption was significantly reduced. This study provides a new research direction for the efficient and low-energy desorption of CO₂ by blended alkanolamine. Full article

The present study aimed to investigate the feasibility of blended amine absorbents in improving the CO₂ alkanolamine-based absorption of multicycle integrated absorption–mineralization (multicycle IAM) under standard operating conditions (20–25 °C and 1 atm). Multicycle IAM is a promising approach that transforms CO₂ emissions into valuable products such as carbonates using amine solvents and waste brine. Previously, the use of monoethanolamine (MEA) as an absorbent had limitations in terms of CO₂ conversion and absorbent degradation, which led to the exploration of blended alkanolamine absorbents, such as diethanolamine, triethanolamine, and aminomethyl propanol (AMP) combined with MEA. The blended absorbent was evaluated in terms of the absorption performance and carbonate production in continuous cycles of absorption, precipitation/regeneration, and preparation. The results showed that the fourth cycle of the blend of 15 wt.% AMP and 5 wt.% MEA achieved high CO₂ absorption and conversion efficiency, with approximately 87% of the absorbed CO₂ being converted into precipitated carbonates in 43 min and a slight degradation efficiency of approximately 45%. This blended absorbent can improve the efficiency of capturing and converting CO₂ when compared to the use of a single MEA, which is one of the alternative options for the development of CO₂ capture and utilization in the future. Full article

Exploring new solvents for efficient acid gas removal is one of the most attractive topics in industrial gas purification. Herein, using 2-tertiarybutylamino-2-ethoxyethanol as an absorbent in a packed column at atmospheric pressure was examined for selective absorption of H₂S from mixed gas streams. In the present work, the acid gas load, H₂S absorption selectivity, acid gas removal ratio, amine solution regeneration performance, and corrosion performance were investigated through evaluating experiments absorbing H₂S and CO₂ by using methyldiethanolamine and 2-tertiarybutylamino-2-ethoxyethanol. The experimental results illustrate that the H₂S absorption selective factors were 3.88 and 15.81 by using 40% methyldiethanolamine and 40% 2-tertiarybutylamino-2-ethoxyethanol at 40 °C, respectively, showing that 2-tertiarybutylamino-2-ethoxyethanol is an efficient solvent for selective H₂S removal, even better than methyldiethanolamine. Based on the consideration of cost, we added 5% TBEE to 35% MDEA to form a blended aqueous solvent. To our satisfaction, the blended amine solvent obtained a 99.79% H₂S removal rate and a 22.68% CO₂ co-absorption rate, while using the methyldiethanolamine alone achieved a 98.33% H₂S removal rate and a 23.52% CO₂ co-absorption rate; the blended solvent showed better H₂S absorption efficiency and selectivity. Taken together, this work provides valuable information for a promising alkanolamine for acid gas removal, and the preliminary study has found that the aqueous blend of methyldiethanolamine and 2-tertiarybutylamino-2-ethoxyethanol is an efficient solvent for selective H₂S removal, which not only extends the application field for sterically hindered amines, but also opens up new opportunities in blended solvent design. Full article