Measurement of polarization parameters impacting on electrodeposit morphology. II, Conventional zinc electrowinning solutions

A new technique for measuring effects of polarization modifiers on nucleation potential and plating potential in polycrystalline electrodeposition was presented in Part I of this series (J. Appl. Electrochem. 32(2002) 1101–1107). This paper presents the

Validation of a vertical channel flow cell for scalable electrowinning studies

A two-compartment vertical channel cell with controlled electrolyte flow and planar cathode surface of adjustable height was constructed. Unlike small cells with only natural mixing, this arrangement allowed simulation of the effects of turbulence over t

Quantification of Aqueous Monoethanolamine Concentration by Gas Chromatography for Postcombustion Capture of CO 2

The availability of reliable analytical methods for measuring amine concentrations is necessary for optimum operation of aqueous amine CO 2 separation systems being employed for postcombustion capture (PCC) of CO2. A GC-FID (gas chromatography with flame ionization detection) method is described for the reliable quantification of 30% (w/w) monoethanolamine (MEA) in severely degraded solvent samples. The observation of intermittent splitting of the MEA peak was a major concern with this approach. The use of a wide-bore column led to improved MEA peak resolution and peak shape. The reliability and robustness of the GC-FID method were assessed by analyzing degraded 30% (w/w) MEA solvent samples from CSIRO's pilot plant at AGL's Loy Yang power station in Victoria, Australia. The results were compared with those obtained by titration and total organic carbon (TOC) measurements of the same samples. The MEA concentrations obtained by the GC-FID and titration methods were statistically similar. In contrast, the MEA concentrations calculated from TOC were consistently higher than those obtained by both GC-FID and titration. © 2014 American Chemical Society

Towards Commercial Scale Postcombustion Capture of CO 2

Chemical absorption with aqueous amine solvents is the most advanced technology for postcombustion capture (PCC) of CO2 from coal-fired power stations and a number of pilot scale programs are evaluating novel solvents, optimizing energy efficiency, and validating engineering models. This review demonstrates that the development of commercial scale PCC also requires effective solvent management guidelines to ensure minimization of potential technical and environmental risks. Furthermore, the review reveals that while solvent degradation has been identified as a key source of solvent consumption in laboratory scale studies, it has not been validated at pilot scale. Yet this is crucial as solvent degradation products, such as organic acids, can increase corrosivity and reduce the CO2 absorption capacity of the solvent. It also highlights the need for the development of corrosion and solvent reclamation technologies, as well as strategies to minimize emissions of solvent and degradation products, such as ammonia, aldehydes, nitrosamines and nitramines, to the atmosphere from commercial scale PCC. Inevitably, responsible management of aqueous and solid waste will require more serious consideration. This will ultimately require effective waste management practices validated at pilot scale to minimize the likelihood of adverse human and environmental impacts from commercial scale PCC