CO2 In Monoethanolamine Solution Research Articles

Experimental study of CO2 solubility in high concentration MEA solution for intensified solvent-based carbon capture

The solvent-based carbon capture process is the most matured and economical route for decarbonizing the power sector. In this process, aqueous monoethanolamine (MEA) is commonly used as the solvent for CO2 scrubbing from power plant and industrial flue gases. Generally, aqueous MEA with 30 wt% (or less) concentration is considered the benchmark solvent. The CO2 solubility data in aqueous MEA solution, used for modelling of the vapour-liquid equilibria (VLE) of CO2 in MEA solutions, are widely published for 30 wt% (or less) concentration. Aqueous MEA with higher concentrations (from 40 to 100 wt%) is considered in solvent-based carbon capture designs with techniques involving process intensification (PI). PI techniques could improve the process economics and operability of solvent-based carbon capture. Developing PI for application in capture process requires CO2 solubility data for concentrated MEA solutions. These data are however limited in literature. The modelling of the vapour-liquid equilibria (VLE) of CO2 in MEA solutions for PI-based solvent capture techniques involving stronger MEA solution of about 80 wt% concentration requires solubility data at the concentration. In this study, the data for 80 wt% MEA is presented for 40,60, 100 and 120oC. The experimental technique and analytical procedure in this study were validated by comparing the measurements for 30 wt% MEA with data from the literature. The data from this study can be fitted to VLE models such as electrolyte NRTL, extended UNIQUAC etc. which is an important component of solvent-based capture model using MEA as the solvent. More accurate VLE models will improve the prediction accuracy of capture level, rich loading etc. using PI-based solvent-based capture model.

High-throughput CO2 capture for biogas purification using monoethanolamine in a microtube contactor

Abstract The utilization of biogas is somewhat limited by its composition especially CO2. The CO2 content in biogas can be substantially reduced via chemical absorption. In this work, the absorption performance of CO2 removal from biogas using aqueous monoethanolamine (MEA) in a T-type microchannel (0.5 × 0.5 × 60 mm3) was experimentally investigated. The effects of operating parameters including MEA-to-CO2 molar ratio, temperature, pressure, and flow rate of MEA solution were studied in terms of main and interaction effects via statistical analysis. Temperature and MEA-to-CO2 molar ratio showed relatively strong influence on both %absorption and the liquid-side volumetric mass transfer coefficient. A positive confounding effect between these two parameters was also present. Hence, high temperature and high molar ratio resulted in high performance CO2 removal from biogas. Methane purity of 90% was obtained with the molar ratio of 1.8 at 50 °C. The kLa of 517 s−1 was achieved at the MEA-to-CO2 molar ratio of 5:1, 50 °C, 2 bar, and 3 mL/min of the MEA solution. In addition, the absorption flux of CO2 in MEA solution, overall mass transfer coefficient, and kinetic rate constant were evaluated to interpret the experimental results.

Model study of CO2 absorption in aqueous amine solution enhanced by nanoparticles

An investigation for the enhancement of nanoparticles (TiO2, MgO, SiO2) on the mass transfer for CO2 absorption was presented through both the experiment method and a 3-D unsteady model. The effects of nanoparticle loadings, nanoparticle diameters, nanoparticle species, solution species, experimental temperature and the CO2 initial volume fraction on the CO2 absorption were investigated in this paper. Considering the chemical reaction between gas and solution, a 3-D unsteady model was developed to study the mass transfer for CO2 absorption enhanced by nanoparticles in monoethanolamine (MEA) solution. Based on the analysis of zwitterion mechanism in the process of chemical reaction between MEA and CO2, it was shown that the rate of chemical reaction is proportional to the concentration of CO2 due to the large MEA concentration and the zero-order reaction in the liquid membrane. Further, the differential equation of mass transfer in three dimensions was set up, which is related to the rate of chemical reaction and the random distribution of nanoparticles. The random distribution of nanoparticles in a fluid element was determined by Monte Carlo method. In addition, the absorption experiments of CO2 in MEA solution using the bubbling reactor were carried out, which could also verify the correctness of the developed model.

Raugh-Rapid Determination Methods for Both Concentration of Absorbent and CO2 in Monoethanolamine Solution for CO2 Removal

Raugh-Rapid Determination Methods for Both Concentration of Absorbent and CO2 in Monoethanolamine Solution for CO2 Removal