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Electrochemical enhancement and inhibition of calcium carbonate deposition

Electrochemical enhancement and inhibition of calcium carbonate deposition

Category
Journal publication
Abstract
Calcium carbonate is by far the most widespread scaling material. Its deposition in pipes andflowlines has been along-standing problem for many industries. Hence, a lot of research is devoted to scale inhibition. One of thecalcium carbonate scale management methods relies on removal of calcium ions from scaling solution byelectrochemically enhanced deposition. Application of potential between two electrodes may result in oxygenreduction and water electrolysis. Both processes change the local pH in close proximity to the electrodes.Solution close to the anode is becoming acidic while that close to the cathode alkaline. Solubility of calciumcarbonate is pH dependent. The alkaline pH in the vicinity of the cathode promotes precipitation of calciumcarbonate. On the other hand, the acidic environment near the anode prevents anode from scaling.In this paper we show how the cathodic and anodic processes, respectively, accelerate and prevent scaledeposition on graphite electrode surfaces. The growth of calcium carbonate at different calcium ion con-centrations and different voltage magnitudes applied were followed using X-ray computed tomography. Themorphology of the deposited calcium carbonate was studied using the scanning electron microscopy. Thepolymorphic forms of calcium carbonate deposited at different voltage magnitudes were identified using X-raypowder diffraction. A strong correlation between the scaling rate, the average crystallite size and the voltageapplied was observed.
Client
  • Norges forskningsråd / 285568
Language
English
Affiliation
  • SINTEF Industry / Petroleum
  • SINTEF Industry / Materials and Nanotechnology
  • Norwegian University of Science and Technology
Year
2020
Published in
Journal of Environmental Chemical Engineering
ISSN
2213-3437
Volume
8
Booklet
5