出版物：Geochimica et Cosmochimica Acta 卷：115 页：183–204

DOI：http://dx.doi.org/10.1016/j.gca.2013.04.010 出版年份：April 2013

摘要：Accurate values of diffusion coefficients for carbon dioxide in water and brine at reservoir conditions are essential to our understanding of transport behavior of carbon dioxide in subsurface pore space. However, the experimental data are limited to conditions at low temperatures and pressures. In this study, diffusive transfer of carbon dioxide in water at pressures up to 45 MPa and temperatures from 268 to 473 K was observed within an optical capillary cell via time-dependent Raman spectroscopy. Diffusion coefficients were estimated by the least-squares method for the measured variations in carbon dioxide concentration in the cell at various sample positions and time. At the constant pressure of 20 MPa, the measured diffusion coefficients of carbon dioxide in water increase with increasing temperature from 268 to 473 K. The relationship between diffusion coefficient of carbon dioxide in water [D(CO2) in m2/s] and temperature (T in K) was derived with Speedy–Angell power-law approach as:

D(CO2)=D0[T/Ts-1]^mD(CO2)=D0[T/Ts-1]m

where D0 = 13.942 × 10−9 m2/s, Ts = 227.0 K, and m = 1.7094. At constant temperature, diffusion coefficients of carbon dioxide in water decrease with pressure increase. However, this pressure effect is rather small (within a few percent).

I.M.Chou(周义明)：博士，资深研究员。1974年获得美约翰霍普金斯大学地球化学博士学位。常年任海外华人地球科学技术协会主席。回国工作。回国前就职于美国国家地质调查局，从事矿物及天然流体热力学、地质流体的物理化学、天气水合物的物理化学及二氧化碳开发等研究工作。