Nonaqueous CO 2 absorbents, composed of secondary alkanolamines and 2-alkoxyethanols, have attracted much attention for an energy-efficient CO 2 capture process. In this work, densities and viscosities of partially CO 2 -loaded mixtures of 2-(butylamino)ethanol (BAE) + 2-butoxyethanol (EGBE) and 2-(ethylamino)ethanol (EAE) + EGBE were measured at atmospheric pressure over the temperature range of (293.15 to 353.15) K with amine mass fraction ( w 1 ) of (0.10, 0.30 and 0.50) containing various CO 2 loading. With increasing CO 2 loadings, significant increases in both density and viscosity were observed. Dimensionless ρ loaded · ρ CO2-free −1 and η loaded · η CO2-free −1 from the CO 2 -free and CO 2 -loaded systems were fitted by proposed correlations as a function of temperature, amine concentration and CO 2 loading. The calculated values of density and viscosity from the correlations are in good agreement with the experimental results, with AADs within 0.15% and 1.60% for density and viscosity respectively. The dramatic increase in viscosity of carbonated solutions was interpreted by the intermolecular interactions and the formation of ionic products in the mixtures based on the FTIR spectral results.
Coal-fired flue gas is a major source of greenhouse gas CO 2 . Phase-change absorbents can be used to reduce energy consumption associated with regeneration during CO 2 capture. In this study, N,N-dimethylbutylamine (DMBA) and N,N-dimethylbutylamine (DEEA) were mixed to develop phase-change absorbents, and the reaction kinetics of CO 2 absorption in the absorbents were examined. A bubbling device was used to prepare phase-change absorbents with different CO 2 loading levels. The physico-chemical parameters of the absorbents under different conditions were specified, and the changes in the CO 2 loading of the upper and lower layers of the absorption solutions after a liquid–liquid separation were analyzed. A wetted-wall column was subsequently used to investigate the effects of temperature, CO 2 loading, gas flow rate, and DMBA/DEEA composition ratio on CO 2 absorption rate. This study determined that the flow velocity, reaction temperature, and CO 2 loading affected the CO 2 absorption rates to a certain extent. In addition, comparing the reactive properties of the 4M DMBA + 2M DEEA and 2M DMBA + 4M DEEA absorbents under the same experimental conditions revealed that the 4M DMBA + 2M DEEA absorbent exhibited higher absorption rate and reaction stability. A kinetics model also indicated that the CO 2 absorption of the phase-change absorbents used in this study was mainly affected by the liquid film diffusion process. This study contributes theoretically to the development of CO 2 absorption technologies.
In the realm of postcombustion carbon capture, diethylenetriamine (DETA), recognized for its substantial CO2 absorption capacity, presents a formidable challenge due to its corrosive impact on equipment. This study delves into the corrosion behavior of 20# carbon steel immersed in DETA solutions under varying conditions, employing weight loss and electrochemical methods. The investigation incorporates scanning electron microscopy/energy-dispersive spectroscopy and X-ray diffraction analyses for characterization. Corrosion experiments were also conducted in monoethanolamine (MEA) solutions for a comparative analysis. Results from the corrosion tests in DETA solutions mirror the temperature-dependent corrosion rate (CR) observed in MEA. However, a distinctive trend emerges as the CO2 loading of DETA increases from 0.2 mol CO2/mol amine to 1.2 mol CO2/mol amine, leading to a continuous decrease in the CR of carbon steel─contrary to MEA solutions. This anomaly is attributed to DETA’s robust complexing ability with metal ions and its elevated solubility of Fe2+ in solution. Additionally, an examination of the corrosion mechanism in the presence of oxygen was conducted through characterizing the specimen surface and solution precipitates postexperiment. The absence of a protective FeCO3 layer can be attributed to insufficient concentrations of free Fe2+ and CO32– in the solution, failing to achieve the minimum saturation required for protective film formation. The insights gained from studying the corrosion behavior of carbon steel in DETA solutions lay the groundwork for subsequent developments in corrosion inhibitors.
危险品化学品经营许可证（带存储）