TY - GEN

T1 - The effect of pulse current on energy saving during Electrochemical Chloride Extraction (ECE) in concrete

A1 - Sun,Tian R.

A1 - Geiker,Mette R.

A1 - Ottosen,Lisbeth M.

AU - Sun,Tian R.

AU - Geiker,Mette R.

AU - Ottosen,Lisbeth M.

PB - Taylor & Francis - Balkema

PY - 2012

Y1 - 2012

N2 - Energy consumption is a factor influencing the cost of Electrochemical Chloride Extraction (ECE) in concrete. The aims of this work were to investigate the possibility for energy saving when using a pulsed electric field during ECE and the effect of the pulsed current on removal of chloride. Four experiments with artificially polluted concrete under same charge transfer were conducted. Results showed that the energy consumption was decreased 15% by pulse current in experiments with 0.2 mA/cm2 current density, which was higher than that of 0.1 mA/cm2 experiments with a decrease of 9.6%. When comparing the voltage drop at different parts of the experimental cells, it was found that the voltage drop of the area across the concrete was the major contributor to energy consumption, and results indicated that the pulse current could decrease the voltage drop of this part by re-distribution of ions in pore fluid during the relaxation period. However, probably due to the observed re-adsorption of chloride by concrete in pulse current, there was no significant difference between constant and pulse current experiments in relation to removal of chloride. Use of an anion exchange membrane impeded the H+ ions from the anodic reaction entering the concrete, and the pulse current also demonstrated a positive effect on the energy consumption across the membrane by diminishing the concentration polarization.

AB - Energy consumption is a factor influencing the cost of Electrochemical Chloride Extraction (ECE) in concrete. The aims of this work were to investigate the possibility for energy saving when using a pulsed electric field during ECE and the effect of the pulsed current on removal of chloride. Four experiments with artificially polluted concrete under same charge transfer were conducted. Results showed that the energy consumption was decreased 15% by pulse current in experiments with 0.2 mA/cm2 current density, which was higher than that of 0.1 mA/cm2 experiments with a decrease of 9.6%. When comparing the voltage drop at different parts of the experimental cells, it was found that the voltage drop of the area across the concrete was the major contributor to energy consumption, and results indicated that the pulse current could decrease the voltage drop of this part by re-distribution of ions in pore fluid during the relaxation period. However, probably due to the observed re-adsorption of chloride by concrete in pulse current, there was no significant difference between constant and pulse current experiments in relation to removal of chloride. Use of an anion exchange membrane impeded the H+ ions from the anodic reaction entering the concrete, and the pulse current also demonstrated a positive effect on the energy consumption across the membrane by diminishing the concentration polarization.

KW - Adsorption

KW - Charge transfer

KW - Electric fields

KW - Energy conservation

KW - Energy utilization

KW - Experiments

KW - Ions

KW - Repair

KW - Retrofitting

KW - Chlorine compounds

SN - 9780415899529

BT - Concrete Repair, Rehabilitation and Retrofitting III

T2 - Concrete Repair, Rehabilitation and Retrofitting III

SP - 899

EP - 903

ER -