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N,N-Diethylethanolamine (DEEA), which can be prepared from renewable resources, represents a candidate alkanolamine for CO2 removal from gaseous streams. In this work, the reaction of CO2 with aqueous solutions containing N,N-diethylethanolamine (DEEA) was studied in a stirred cell reactor with a plane, horizontal gas−liquid interface, in the range of temperatures 298−308 K. The DEEA concentration in the aqueous solutions was varied in the range 2−3 kmol/m3. The liquid-side mass transfer coefficient and a combined parameter comprising the reaction rate constant and the diffusivity and solubility of CO2 in DEEA solutions were evaluated. The effect of the addition of piperazine (PIP) as a possible absorption activator was studied, and it was found that even with a small amount of PIP (0.1 kmol/m3) added, the CO2 absorption rate increased.

Aqueous solutions containing alkaline salts of carboxylic or sulfonic amino acids represent candidate solvents with good potential for carbon dioxide (CO2) capture. In the present work, the CO2 reactions with potassium salts of glycine (aminoacetic acid) and taurine (2-aminoethanesulfonic acid) in aqueous solutions are investigated using a stirred-cell reactor. The reaction pathways are comprehensively described using the zwitterion and the termolecular mechanism. The investigated reactions belong to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO2 reaction with potassium glycinate is determined, and its value at 303 K is evaluated to be 6.29 m3/(mol s). The liquid-side mass-transfer coefficient is estimated, and its value (0.006 cm/s) is consistent with those typical for stirred-cell reactors. Finally, it is determined that potassium glycinate promotes the activity of tertiary amines (e.g., N,N-diethylethanolamine).

One major goal of biology is to provide a quantitative description of cellular physiology. This task is complicated by population effects, which perturb culture conditions and mask the behavior of the individual cell. To overcome these limitations, the construction and operation of a microfluidic bioreactor is presented. The new reactor concept guarantees constant environmental conditions and single cell resolution, thus it was named Envirostat (environment, constant). In the Envirostat, cells are contactless trapped by negative dielectrophoresis (nDEP) and cultivated in a constant medium flow. To control chip temperature, a Peltier device was constructed. Joule heating by nDEP was quantified with Rhodamine B in dependence of applied voltage, field mode, medium conductivity, and flow velocity. The integration of the Joule heating effect in the temperature control allowed setting and maintaining the cultivation temperature. For single cell cultivation of Saccharomyces cerevisiae, medium composition changes below 0.001% were estimated by computational fluid dynamic simulation. These changes were considered not to influence cell physiology. Finally, single S. cerevisiae cells were cultivated for more than four generations in the Envirostat, thus showing the applicability of the new reactor concept. The Envirostat facilitates single cell research and might simplify the investigation of hitherto difficult to access biological phenomena such as the true regulatory and physiological response to genetic and environmental perturbations.

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The CO 2 reaction with alkanolamines has received considerable attention by both academia and industry. Commonly, the formation of the carbamate during the CO 2 reaction with primary, secondary, and sterically hindered amines is described by a two-step zwitterion mechanism. Alternatively, a single-step termolecular reaction mechanism can also be used to govern carbamate formation. The experimental kinetic data for several amine-based solvents are consistent with this mechanism, and it can satisfactorily explain fractional-order and higher-order kinetics. However, up to now, the termolecular reaction mechanism has not been properly discussed. Here, this mechanism is described in detail, a simple procedure to estimate the kinetic parameters is outlined, and the termolecular reaction kinetics for various systems comprising individual and mixed amines is reviewed.