Imperial College London

ProfessorGeoffreyMaitland

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Energy Engineering
 
 
 
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Contact

 

+44 (0)20 7594 1830g.maitland Website

 
 
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Assistant

 

Mrs Sarah Payne +44 (0)20 7594 5567

 
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Location

 

401ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Li:2017:10.1016/j.fluid.2017.11.023,
author = {Li, X and Peng, C and Crawshaw, JP and Maitland, GC and Trusler, JPM},
doi = {10.1016/j.fluid.2017.11.023},
journal = {Fluid Phase Equilibria},
pages = {253--263},
title = {The pH of CO<inf>2</inf>-saturated aqueous NaCl and NaHCO<inf>3</inf>solutions at temperatures between 308 K and 373 K at pressures up to 15 MPa},
url = {http://dx.doi.org/10.1016/j.fluid.2017.11.023},
volume = {458},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - The pH is a critical variable for carbon storage in saline aquifers because it affects the reaction rate and equilibrium state of the reservoir rocks, thus influencing the rates of mineral dissolution or precipitation and the integrity of caprocks. In this work, high-pressure pH and Ag/AgCl-reference electrodes were used to measure the pH of CO 2 -saturated aqueous solutions of NaCl and NaHCO 3 . The expanded uncertainty of the pH measurements is 0.20 at 95% probability. For CO 2 -saturated NaCl(aq), measurements were carried out at total pressures from (0.37 to 15.3) MPa and temperatures from (308 to 373) K with NaCl molalities of (1, 3 and 5) mol·kg −1 . For CO 2 -saturated NaHCO 3 (aq), the pH was measured at total pressures from (0.2 to 15.3) MPa and temperatures from (308 to 353) K with NaHCO 3 molalities of (0.01, 0.1 and 1) mol·kg −1 . The pH was found to decrease with increase in pressure and with decrease in temperature for both CO 2 -saturated NaCl and NaHCO 3 solutions. For CO 2 -saturated NaCl(aq), the pH was observed to decrease with increase of salt molality, while for CO 2 -saturated NaHCO 3 , the opposite behaviour was observed. The results have been compared with predictions obtained from the PHREEQC geochemical simulator (version 3.3.9) incorporating the Pitzer activity-coefficient model with parameters taken from the literature. For CO 2 -saturated NaCl(aq), agreement to within ±0.2 pH units was observed in most cases, although deviations of up to 0.3 were found at the highest molality. In the case of CO 2 -saturated NaHCO 3 (aq), the experimental data were found to deviate increasingly from the model with increasing salt molality and, at 1 mol·kg −1 , the model underestimated the pH by between 0.3 and 0.7 units.
AU - Li,X
AU - Peng,C
AU - Crawshaw,JP
AU - Maitland,GC
AU - Trusler,JPM
DO - 10.1016/j.fluid.2017.11.023
EP - 263
PY - 2017///
SN - 0378-3812
SP - 253
TI - The pH of CO<inf>2</inf>-saturated aqueous NaCl and NaHCO<inf>3</inf>solutions at temperatures between 308 K and 373 K at pressures up to 15 MPa
T2 - Fluid Phase Equilibria
UR - http://dx.doi.org/10.1016/j.fluid.2017.11.023
UR - http://hdl.handle.net/10044/1/55431
VL - 458
ER -