CO₂ Capture Using Monoethanolamine in a Bubble‐Column Scrubber

Abstract

A continuous bubble-column scrubber, capturing CO 2 gas by monoethanolamine (MEA) solution in a pH-stat operation, is used to search for optimum process parameters by means of the Taguchi method. The process variables are the pH of the solution, gas flow rate, concentration of CO 2 gas, and temperature. From the measured outlet CO 2 gas concentrations, the absorption rate and overall mass transfer coefficient can be determined with the support of a steady-state material balance equation as well as a two-film model. According to the signal-to-noise ratio, the significance sequence influencing the parameters and optimum conditions can be determined. CO 2 concentration and pH value proved to be decisive parameters, while temperature and gas flow rate were minor. Five sets of optimum conditions were obtained and could be further verified by empirical equations.

CO2 Capture and Crystallization of Ammonia Bicarbonate in a Lab-Scale Scrubber

“…The effects of the pH level and temperature on K G a are obvious, indicating the significance of pH and temperature. However, the K G a, as obtained here, is in the range of 0.0136-0.3302 1/s, which is comparable with other solvents, such as MEA solvent which is in the range of 0.0342-0.881 1/s [28] and NaOH/BaCl 2 /H 2 O, which is in the ranges of 0.0651-0.3396 1/s [5] and 0.015-0.14 1/s for a stirred-tank scrubber using an aqueous ammonia solution as the scrubbing solution [4]. On the other hand, from data reported in literatures [8,13,26,27], the K G a can be recalculated for comparison.…”

Numerical evaluation on the intraparticle transfer in butylene oxidative dehydrogenation fixed-bed reactor over ferrite catalysts

“…Along the flow direction, the difference in the butylene mass fraction distributions in the two cases initially increases and then decreases. This phenomenon is referred to the self-stability described by Chen et al [16]. The self-stability, namely, the interaction between the reactant concentration and the reaction rate, also exists in a fixedbed reactor.…”

“…The effectiveness factor is defined as the ratio of the actual reaction rate to the surface reaction rate of the particle. In previous modeling studies, the effectiveness factor was regarded as 1 when the surface reaction rate is 0 [14,16,28]. If the intrinsic reaction rate is zero, the reaction effectiveness factor is defined as 1 in this study.…”

“…However, this model was not built based on the CFD approach. Most of the early multi-scale modeling efforts in this field are practically multi-scale gas-solid two-phase FBRs [16]. Furthermore, to the best knowledge of our knowledge, no open report has been published regarding the development of a multiscale CFD model for catalytic fixed-bed reactors.…”

Application of a Wire‐Mesh Sensor for the Study of Chemical Species Conversion in a Bubble Column

“…One such model reaction is the chemical absorption of carbon dioxide in a base solution such as sodium hydroxide. The popularity of this reaction system results from its industrial relevance, e.g., in CO 2 scrubbing [3,4]. The chemical absorption of CO 2 is limited by the mass transfer resistance from the gas into the liquid phase.…”