Sen Liu

Hunan University · Department of Chemical Engineering

The kinetics of CO2 absorption in ethanolamine (MEA)+H2O+ethanol systems was investigated using stopped-flow apparatus. The first-order reaction rate constant (k0) values were tested with varying H2O and MEA concentrations. Transiting from the aqueous to non-aqueous solvents, the k0 decreases and the reaction order for MEA shifts from 1.05 to 1.88....

In order to establish an accurate kinetic model for the aqueous amine blends, monoethanolamine (MEA), 2‐(ethylamino) ethanol (EAE), and 3‐(diethylamino)‐1‐propanol (3DEA1P) have been chosen as a typical CO2 absorption trisolvents. The reaction kinetics of aqueous amine blends with carbon dioxide have been investigated first combining experiments an...

High heat duty is an urgent challenge for industrial applications of amine-based CO2 capture. In this work, we report a novel, stable, efficient, and inexpensive Ni-HZSM-5 catalyst to reduce the heat duty. The density functional theory (DFT) calculations successfully explain the catalytic performance. The catalytic activity associates with the comb...

A new sulfolane/secondary amine biphasic absorbent, sulfolane/2-methylaminoethanol (MAE) solution, was developed for post-combustion CO2 capture (PCC). Surprisingly, using 4M/5M sulfolane/MAE solution saves about 60% energy consumption for CO2 stripping when compared with traditional aqueous 5M monoethanolamine (MEA) solutions. First, we theoretica...

The stopped-flow technique was applied for the investigation of kinetics of CO2 absorption into loaded MDEA solution over the range of MDEA concentration of 0.4 to 1.0 kmol/m³, CO2 loading of 0.14 to 0.17 mol CO2/mol amine and the temperature of 293 to 308 K. The kinetics of unloaded MDEA was also investigated for the comparison and a huge differen...

A convenient and metal-free protocol for the synthesis of 2-arylthio(seleno)imidazoles from imidazoles and disulfides (diselenides) was developed through the direct thiolation (selenylation) of imidazoles promoted by 0.5 equiv. of iodine. This process is scalable and tolerates a wide spectrum of disulfides (diselenides) to deliver products in high...

The aim of this project was to develop a thermodynamic model for the vapour-liquid equilibrium of an amine-water-carbon dioxide system and to evaluate the CO2 capture performance of aqueous EMAB solution. The structurally modified tertiary amine 4-(ethyl-methyl-amino)-2-butanol (EMAB) was chosen because of its molecular structure-activity relations...

The sulfolane was, surprisingly, found to be a universal phase splitting solvent in a serial of aqueous primary alkanolamine solution for CO2 removal, the reaction product of carbamate and hydrophilicity of amine can be the key factor for CO2 triggering phase change, also the phase change can have significant effect on CO2 absorption performance. T...

In order to establish an integrative mass transfer coefficient (KGaV) model for CO2 absorption into blended monoethanolamine (MEA)/1-dimethylamino-2-propanol (1DMA2P) solution in packed column, the models of CO2 Henry’s law constants (HeCO₂-MEA/1DMA2P) and the equilibrium CO2 solubility (αeq) were constructed. The experimental produced data can be...

To figure out the steric hindrance and its magnitude effects on CO2 absorption performance and Brønsted correlations of primary and secondary alkanolamines, the pKa values and kinetics data (second order reaction rate, k2) were investigated for nine alkanolamines at 293–313 K using pH meter and stopped-flow technique. The tested amines include mono...

To get a more accurate mass transfer coefficient model of CO2 into aqueous Monoethanolamine (MEA)/N,N-dimethylethanolamine (DMEA) solution in a packed column, the Henry’s law constant, equilibrium CO2 solubility, volumetric overall mass transfer coefficient (KGav), overall gas-phase mass transfer coefficient (KG) and the effective gas-liquid interf...

In order to study the effect of heat-stable salts (HSSs) on the CO2 absorption performance of amine solution, the CO2 absorption/desorption rates and cyclic CO2 capacity of 30 wt% (monoethanolamine) MEA solutions in the presence of various acidic degradation products were comprehensively investigated systematically by an improved rate-based screeni...

The objective of the present work was to find the accurate kinetic models and mechanism for CO2 absorption into tertiary amine solution, aiming at understanding the contribution of the CO2 reaction with H2O, OH⁻, and tertiary amines on the overall reaction rate. First, the kinetics of CO2 absorption into water instead of a buffer solution were stud...

The structure-activity relationship of eleven diamines and MEA was investigated in order to provide guidance for the selection of the potential CO2 capture absorbent. The effects of methyl, ethyl, hydroxyl groups, and distance between N groups in molecular structures were evaluated experimentally by using the rapid fast screening method and compute...

The carbon dioxide (CO2) capture potential of amine blends, formed by mixing N,N-Diethylethanolamine (DEEA) and piperazine (PZ), were estimated using an improved rapid screening method. Absorption and desorption experiments were carried out at 313.15 K and 353.15 K to determine the absorption rate, cyclic CO2 capacity and regeneration rate for 2 mo...

An improved fast screening method, i.e. the multiple fast screening method, was developed to quickly screen high efficiency solvents for post combustion CO2 capture, especially for the existing amine-based CO2 capture processes. This screening method, taking into account the CO2 absorption capacity as well as the absorption and desorption efficienc...

New vapor-liquid equilibrium (VLE) experimental data has been collected for DEEA in the concentration range of 1 to 4M at temperatures of 293K, 313K, 333K, and 353K for CO2 partial pressure in the range from 6.2kPa-100.8kPa. An empirical model has been established based on the experimental data. A comparison of experimental and predicted data gave...

New vapor-liquid equilibrium (VLE) experimental data has been collected for DEEA in the concentration ranges of 1–4 M with temperature at 293 K, 313 K, 333 K, and 353 K for CO2 partial pressure in the range from 6.2 kPa to 100.8 kPa. An empirical model has been established based on the experimental data. A comparison of experimental and predicted d...

An improved fast screening method, i.e. the multiple fast screening method, was developed to quickly screen high efficiency solvents for post combustion CO2 capture, especially for the existing amine-based CO2 capture processes. The method was based on an integrated CO2 absorption-desorption process, where the absorption process was performed at 40...

The major drawback of using amine for carbon dioxide (CO2) capture is the contradiction between lower regeneration heat duty and high CO2 absorption rate. One way to overcome this problem is to develop an alternative absorbent with improved performance of sorption and desorption CO2, which can make energy consumption decrease. A quick method was us...