journal of mmij

© 2021 The Mining and Materials Processing Institute of Japan91

http://doi.org/10.2473/journalofmmij.137.91

*Received 18 December, 2019; accepted for publication 12 July, 2021a. Ph.D. course student, Department of Mechanical Engineering, Tokyo Institute of

Technology, 2-12-1-I6-33, Ookayama, Meguro-ku, Tokyo, 152-8550, Japanb. Master course student, Department of Mechanical Engineering, Tokyo Institute of

Technology, 2-12-1-I6-33, Ookayama, Meguro-ku, Tokyo, 152-8550, Japanc. Professor, Department of Mechanical Engineering, Tokyo Institute of Technology,

2-12-1-I6-33, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan[*For Correspondence] E-mail: [email protected]

1. Introduction

Dissolution of trapped phase into flowing water inside

a porous medium is important in various hydrogeology

applications, such as geological carbon sequestration (GCS)1-3).

In GCS, CO2 gas is injected into deep saline aquifer to be

sequestered. Similarly, the CO2 gas will be trapped and

dissolved gradually. This kind of CO2 trapping is termed as the

solubility trapping. As the CO2 gas dissolves into water, the

reservoir pressure decreases. As a result, more CO2 gas can be

injected. In addition, the trapping safety is improved because the

CO2 is in the form of solute.

The studies of gas dissolution into flowing water inside a

porous medium, however, are still limited. The measurement of

dissolution rate was mainly performed with the combination of

gravimetric and effluent concentration analysis4-6). As a result,

the characteristics of the trapped phase were unknown, and thus

the trapped phase interfacial area was also unknown. Without

the information of the trapped phase interfacial area, the mass

transfer coefficient cannot be calculated as well.

The studies of dissolution mass transfer of non-aqueous

phase liquid (NAPL), on the other hand, have been performed

rigorously7-12) with various methods for the applications of

groundwater contamination and decontamination. By using

micro-tomography technique10-12), the trapped phase was able

to be monitored, and thus the trapped phase interfacial area and

mass transfer coefficient can be calculated. Given the similar state

between the gases and NAPLs cases, a similar result is expected.

Previously, we have conducted dissolution experiments

of CO2 gas into flowing water inside a porous medium by

using micro-tomography techniques and found that the

dissolution behavior of CO2 gas is different than the reported

NAPL cases13). In the case of CO2 gas, the dissolution occurs

in two stages, whereas NAPL occurs only in one stage. We

were not sure whether this behavior only occurs in CO2 gas

or also other gases because the dissolution of trapped gas into

flowing inside a porous medium has never been observed with

a micro-tomography technique, except this CO2 gas. The main

difference between CO2 gas and NAPL is the high dissolution

ratio of CO2 gas, which is the ratio of solubility to density.

Therefore, the dissolution ratio could be the point of interest in

this phenomenon.

In this report, we observed the dissolution of four gas

species, which are CO2, N2, O2, and Ar gases, into flowing

water inside a porous medium by using a micro-tomography

technique. The trapped phase characteristics and interfacial area

were able to be measured, and thus mass transfer coefficient

can be calculated. Given the obtain parameters, we explore the

possible reason for this unique dissolution behavior of CO2 by

comparing it with N2, O2, and Ar gas species.

2. Experimental setup

To generate the porous media, water-wet angular particles

made of plastic resin with the size range of 250–425 μm (XH

series, Ube Sand Engineering Co. Ltd) were used. The particles

are angular in shape with sphericity and roundness similar to

silica sands14-16). These particles were selected because they

are inert and do not have internal porosity. Hence, any chemical

reaction and effect of particle internal porosity can be avoided.

For the packing of the porous media, these particles were

packed inside a cylindrical container with an inner diameter

of 10 mm up to the height of 14.5±0.5 mm. To control the

reproducibility, all of the packings were performed under the

A Unique Dissolution Behavior of Trapped CO2 into Flowing Water Inside a Porous Medium Compared with Other Gases*

by Anindityo PATMONOAJIa*, Muhammad NASIRb, Mohammad Azis MAHARDIKAa, Yun SHEa and Tetsuya SUEKANEc

Dissolution of gas into flowing water inside a porous medium is important in various hydrogeology processes, such as geological carbon sequestration (GCS). The dissolution rate of CO2 controls the amount of CO2 injection and the safety of the GCS process. In this report, we investigated the dissolution behavior of four gas species, i.e., CO2, O2, N2, and Ar, into flowing water inside a porous medium by using micro-tomography. The trapped gas characteristics can be observed, and thus interfacial area and mass transfer coefficient can be calculated. Compared with the other gases, we found that the dissolution behavior of CO2 gas is unique, and the mass transfer coefficient is one order of magnitude lower than other gases. We believe that the high dissolution ratio of CO2 gas could have generated a layer of the high solute region around the trapped CO2 gas, disrupting the mass transfer process.KEY WORDS:　 Porous Media, Dissolution, Carbon Dioxide, Mass Transfer Coefficient, Micro-Tomography

地球環境工学特集：二酸化炭素地中貯留に関わる最新の研究動向

Vol.137, No.9, 2021

BY NC ND

Journal of MMIJ

92© 2021 The Mining and Materials Processing Institute of Japan http://doi.org/10.2473/journalofmmij.137.91

Anindityo PATMONOAJI, Muhammad NASIR, Mohammad Azis MAHARDIKA, Yun SHE, Tetsuya SUEKANE

same packing method. The particles were poured gradually into

the cylinder container under vibration to generate close random

packing classification17). In addition, cylindrical sintered glass

plates with a diameter and a thickness around 10 mm and 3.8

mm, respectively, were placed on the inlet and outlet to generate

uniform flow. By using gravimetric measurement, the porosity

was about 0.45±0.005, whereas by using single-phase water

flooding measurement, the permeability about 1.3×10-10 m2.

For the flowing phase, degassed deionized (DDI) water

was used. To produced the DDI water, deionized water was boiled

and placed in a vacuum chamber for approximately 12 hours.

DDI water was used to avoid contamination by other gases that

could exsolve into the trapped phase during the experiments.

For the trapped phase, four gas species, i.e. CO2, N2, O2, and

Ar, with the purity of 99.9% (GL Sciences Corp.) were used for

separate experiments. The main reason for selecting these gases

is due to their dissolution ratio (Table 1). Application-wise, CO2

gas is used in GCS application, whereas N2 and O2 are used

in groundwater bio-remediation. Additionally, Ar was selected

because of its inert nature. Therefore, if there is an additional

effect from a chemical reaction, it can be compared with this

Ar case. All of the experiments were conducted under room

pressure and temperature (1 atm and 25℃). The properties,

i.e., molecular diffusion coefficient, density, solubility, and

dissolution ratio, are given in Table 1.

For the flow rate control of the gas, a needle type

flowmeter (KOFLOC Kyoto Corp.) was used. To control the

flow rate of the water, 50-ml syringes (Terumo) and a syringe

pump (KD Scientific) were used to control the flow rate of DDI

water into the porous media. A 50-ml syringe was used to avoid

any contamination by other gases to the DDI water.

For the micro-tomography, an X-ray microtomography

scanner (Comscantechno Co. ScanXmate-RB090SS) was

used. To produce the same brightness and contrast throughout

the experiment, the same X-ray intensity (116μA and 65kV)

and power (7.5W) were utilized. During the scanning, the

sample remains still while the X-ray source and detector rotate

around the object. In each rotation, 1000 images were taken

at a 360-degree angle under 90 seconds. These images were

then used to reconstruct a three-dimensional (3D) image with

a resolution of 992×992×992 voxels and a voxel size of

16.472 μm. However, due to the X-ray beam problems, about

50 voxels at the top and bottom were unclear. Therefore, the

region of interest in each scan is 600×600×850 voxels, which

corresponds to 9.88×9.88×14 mm3).

To generate homogeneous capillary trapping conditions, a

series of gas and water flooding was performed13,15). At first, the

porous medium was flooded with a flow rate of 10 ml/min up in

5 minutes (100 PV) by using the trapped gas. Afterward, DDI

water was injected with a flow rate of 5 ml/min up in 5 minutes (50 PV). Next, the porous medium was rotated upside down,

and another gas flooding was performed at the flow rate of 10

ml/min up in 5 minutes (100 PV) followed by a higher flow

rate of 50 ml/min in 5 minutes (500 PV). Lastly, another DDI

water injection with the flow rate of the dissolution 0.25 ml/

min, which is the experimental flow rate, was performed. This

flow rate corresponds to Darcy velocity of 117 μm/s or 10.11 m/

day. Once a breakthrough occurs, the sample was scanned with

the micro-CT, and the dissolution mass transfer experiment was

started. In the period of five, ten, or twenty minutes (depending

on the dissolution rate) the porous medium was scanned with

the micro-CT to monitor the decrease in trapped gas volume

due to dissolution. DDI water was then kept injected until all

of the trapped gas dissolved completely. The schematic of the

experimental setup is given in Fig. 1.

3. Data Processing

3・1　Image processingImage processing techniques by using Fiji software18),

which is an image processing package distribution of ImageJ,

were used to identify and extract the amount of trapped gas

from the 3D images taken from micro-CT. The first method

Tabel 1　 Gases properties.

Type of

gas

Molecular diffusion coefficient

(m2/s)23)Density

(kg/m3)

Solubility limit

(kg/m3)

Dissolution ratio

(—)

Schmidt number

(—)

CO2 1.92×10-9 1.842 1.449 0.787 523

N2 1.88×10-9 1.165 0.0175 0.015 534

O2 2.10×10-9 1.331 0.04 0.03 478

Ar 2.00×10-9 1.661 0.053 0.032 502

Fig.1　 Experimental setup schematic.

Vol.137, No.9, 2021



A Unique Dissolution Behavior of Trapped CO2 into Flowing Water Inside a Porous Medium Compared with Other Gases

was to binarized the image. Because the contrast between the

trapped gas and surrounding was significant, direct thresholding

can be performed to separate the trapped gas. By using this

binarized trapped phase image, the volume and surface area of

the trapped gas can be measured. By applying this scheme to the

gas saturated porous media, porosity can also be obtained.

For further processing, each individual trapped gas cluster

can also be identified by utilizing the 3D Object Counter plug-in

in Fiji19). By removing identified trapped clusters smaller than

10 voxels, significant noise removal can be performed.

At the end of this processing, qualitative data 3D images

of the trapped gas distribution and also quantitative data of

porosity, trapped gas volume, and interfacial area of the trapped

gas volume can be obtained. The detailed step of the image

processing can be found in Patmonoaji et al.20).

3・2　Governing equationsTo assess the dissolution rate, the mass transfer coefficient

must be calculated. One dimensional advection-dispersion

equation21) described as follow:

φ (1−S)dC

=d ⎡⎣φ (1−S)Dh

dC ⎤⎦ −u

dC−ρɡφ

dS …… (1)

dt dx dx dx dt

where ρɡ as the trapped phase density, φ as the porosity of

porous medium, S as the trapped phase saturation, which is

the ratio of trapped phase volume and pore volume, C as the

solute concentration in mobile water, x as the distance, t as

the time, and Dh as the hydrodynamic dispersion, is needed to

approximate the solute concentration along the porous medium

during the dissolution mass transfer.

This equation can be simplified under assumptions7-11,13).

First, by assuming a pseudo-steady state, the accumulation

term (the left-hand side term of equation 1) can be neglected.

Second, the dispersion term (the first term at the right-hand

side of equation 1) can also be neglected when the advection is

dominant. By calculating the Peclet number defined as follow:

Pe =ud50

……………………………………………… (2)Dm

with u as the Darcy velocity, d50 as the median particle

diameter, and Dm as the molecular diffusion coefficient of

gas inside water, the dominance of advection transport can be

approximated. Because the Peclet number in this experiment is

between 18.8 and 21, this value is in the regime of advection-

dominant regimes22). Therefore, the effect of dispersion (the

first term at the right-hand side of equation 1) can be neglected.

In addition, Imhoff et al.9) and Patmonoaji et al.13) performed

an order of magnitude analysis and found that the dispersion

term and accumulation term are much lower than the other two

terms (advection and source terms). Therefore, the equation can

be simplified to:

udC

= −ρɡφdS

……………………………………… (3)dx dt

For the calculation of the mass transfer coefficient, a linear

driving force model23) can be used. Because the decrease in

saturation over time is mainly due to dissolution mass transfer,

an equation as followed:

−ρɡφdS

= kadC ……………………………………… (4)dt

with ρ as the trapped phase density, φ as the porosity of porous

medium, k as the mass transfer equation, and a as the specific

interfacial area, can be used. Given the equation 3 and 4,

then the mass transfer coefficient can be calculated. For more

detailed explanation about the governing equation, please refer

to Patmonoaji et al.13)

In addition to Peclet number, Reynolds and Schmidt

numbers defined as follow:

Re =ρwud50

…………………………………………… (5)μ

Sc =ρw

…………………………………………… (6)μw Dm

with ρw as density of water and μw as water dynamic viscosity,

are also needed. Because equation 1 is only for the Darcy flow

regime, the Reynolds number of the system should be lower

than 1021). This system corresponds to a Reynolds number

of 0.04. Therefore, equation 1 can be used. In the case of the

Schmidt number, it is the ratio of momentum diffusion and

molecular diffusion, which shows the effect of the fluid system

on the mass transfer rate23). This Schmidt number is required for

the discussion of the mass transfer coefficient later in this paper.

The values of the Schmidt number of all these fluid systems are

given in Table 1.

4. Results and discussions

4・1　Trapped gas saturationThe trapped phase inside the porous media can be

visualized in 3D by stacking the binarized trapped gas images.

The dissolution mass transfer processes of each trapped gas

species are given in Fig. 2 as 3D images obtained at different

times. In addition, the cross-section average of each trapped gas

species is given in Fig. 3.

Time-wise, the dissolution of CO2 gas occurs with a

higher mass faster rate compared with other gases. As shown in

Fig. 3, most of the CO2 gas dissolved within 20 minutes. For the

other gases, however, O2 and Ar gas dissolved with relatively

similar time at 50 minutes and 70 minutes, respectively. N2

gas was the slowest with the near-complete dissolution time at

170 minutes. Although the initial trapped gas saturation varied

slightly between 0.16–0.20, this dissolution time gives a rough

trend of the dissolution rate. As discussed previously, this trend

can be explained by the difference in dissolution ratio given in

Table 1. The dissolution ratio of CO2 gas is the highest followed

by Ar, O2, and N2 gases. The dissolution ratio represents the

ratio of the solubility limit and density. A High dissolution

ratio demonstrates that a large volume of trapped phase can be

absorbed into the water. Therefore, as shown by the dissolution

rate of these gases, a higher dissolution ratio results in a higher

dissolution rate.

Another pattern is related to the dissolution process.

Dissolution started from the inlet and moved to the outlet,

forming a gradient of trapped gas saturation, called a dissolution

front. This dissolution front is generated because the flowing

Vol.137, No.9, 2021



water has dissolved a significant amount of trapped gas from

the upstream. Therefore, it contained a high concentration

of the trapped gas solute. As a result, the dissolution process

was gradually significantly slowing down before reaching the

downstream. However, by injecting more water, the dissolution

front kept advancing, dissolving the remaining trapped gas

located downstream. In the case of Ar, O2, and N2 gases, the

trapped gases dissolve completely without leaving remaining

bubbles (Fig. 2). As a result, the trapped gas saturation

decreased to zero (Fig. 3) as the dissolution front pass through.

However, in the case of CO2 gas, the dissolution front left some

remaining bubbles, leaving 0.02–0.03 trapped gas saturation.

Afterward, another dissolution front was generated from the

inlet to the outlet, dissolving the remaining bubbles. As a result,

the dissolution process occurred in two dissolution stages. This

unique dissolution behavior of CO2 gas is in agreement with our

previous observation13), which still occurred in different water

flow rates. In the case of NAPL dissolution10,11), the dissolution

of NAPL occurred similarly with Ar, O2, and N2 gases.

Comparison of the dissolution process behavior is more

noticeable with the 3D images of the identified trapped phase

clusters in Fig. 4. Each individual trapped cluster was colored

differently to represent different trapped clusters. As given in

Fig. 4, the dissolution process of Ar, O2, and N2 gases occur

without leaving any remaining bubble, whereas the dissolution

process of CO2 gas left some remaining bubbles with smaller

size.

4・2　Specific interfacial areaTo represent the trapped phase interfacial area, a specific

interfacial area, which is the amount of interfacial area at the

given volume of the porous medium, was used. The specific

interfacial of all of the gases with the function of saturation

is given in Fig. 5. Each data is the averaging of a specific

interfacial area within the trapped gas saturation range of 0.01.

The specific interfacial area of all gases tends to be linear with

trapped phase saturation without significant differences. Using

the prediction model given by Patmonoaji et al.13) as follow:

a = 9.829S [mm−1] …………………………………… (7)

the specific interfacial area at the given trapped phase saturation

for all gases can be approximated with the coeff icient of

determination about 0.975. Therefore, the gas species does not

influence the interfacial area of the trapped gas.

4・3　Mass transfer coefficientFor the mass transfer coefficient, Fig. 6 shows the mass

transfer coefficient of all gases with the function of trapped

gas saturation. Similar to the specific interfacial area in Fig. 5,

each data is the averaging of mass transfer coefficient within

the trapped gas saturation range of 0.01. In the case of Ar, O2,

Fig.3　 The saturation distribution of trapped gases along the porous medium during the dissolution process for all of the gases.

Fig.2　 The 3D images of the trapped gas during the dissolution progress of CO2 (green), N2 (yellow), O2 (blue), and Ar (red) gases.

Vol.137, No.9, 2021




and N2 gases, the mass transfer coefficient increased with the

decrease of saturation. In the case of CO2 gas, however, the

mass transfer coefficient decreased to the lowest value at the

trapped gas saturation around 0.03 but increased again with the

decrease in trapped gas saturation. This valley at trapped gas

saturation around 0.03 corresponds to the transition of the first

dissolution stage to the second dissolution stage. As discussed

in Section 4.1, the dissolution stopped at trapped gas saturation

between 0.02 and 0.03, and then the dissolution occurred again

dissolving this remaining trapped gas saturation.

Another discrepancy is related to the mass transfer

coefficient order of magnitude. In the case of Ar, O2, and N2

gases, the mass transfer coefficient is relatively in the same

range with the difference under one order of magnitude.

However, the mass transfer coefficient of CO2 gas is more than

one order of magnitude lower compared with other gases. At

saturation below 0.1, the mass transfer coefficient of three Ar,

O2, and N2 gases are between 10-6 and 10-5 m/s, whereas the

mass transfer coefficient of CO2 gas is between 10-7 and 10-6

m/s. Therefore, although the dissolution rate of CO2 gas is faster

than Ar, O2, and N2 gases as discussed in Section 4・1, its

mass transfer coefficient is significantly lower. Given the similar

Schmidt number of these gases, which is around 500, the mass

transfer coefficient of these gases should be in the same order.

4・4　Possible reason of CO2 dissolution behavior

The possible reason for the unique behavior of CO2

dissolution behavior and its low mass transfer coefficient could

be related to the rapid dissolution of CO2 gas into the water due

to the high dissolution ratio. Compared with Ar, O2, and N2

gases, CO2 gas exhibits a larger dissolution ratio, which is about

25 to 50 times larger.

Dissolution in porous media is not only governed by the

mass transfer process but also fluid displacement and solute

transport. When the trapped phase dissolves, the decrease in

volume due to dissolution should be filled in with the water,

and the trapped phase solute should be transported away by

the flowing water. If the solute is not transported, the water

surrounding the trapped phase can be saturated with the trapped

phase solute. As a result, the mass transfer process can be

disturbed, and thus mass transfer coefficient decrease.

During the dissolution of CO2 gas, the rapid dissolution of

CO2 gas could generate a local high solute region surrounding

the trapped phase as shown in Fig. 7. As the trapped phase

Fig.4　 The 3D images of the trapped gas cluster during the dissolution progress of all gases. Each cluster is given a random color.

Fig.5　 The specific interfacial area at the given trapped gas saturation for all gases.

Fig.6　 The mass transfer coefficient at the given trapped gas saturation for all gases.

Fig.7　 Illustration of the process of high solute concentration region generation surrounding the trapped CO2 gas.

Vol.137, No.9, 2021



dissolved, it retracted to the center of pores, increasing the

difficulties of the flowing water to transport the solute away

from the surrounding trapped phase. In addition, because the

dissolution process occurred rapidly in CO2 gas, the incoming

water cannot compete with the rapid dissolution of the trapped

phase. As a result, the trapped phase was surrounded by the high

solute concentration region, and thus the mass transfer process

was bog down by this high solute concentration surrounding the

trapped CO2. Because the dissolution ratio of Ar, O2, and N2

gases is not as high as CO2 gas, this phenomenon did not occur

in the case of Ar, O2, and N2 gases.

In addition, this generation of high solute concentration

will be worse if the trapped gas is located inside an isolated

pore that cannot be reached by flowing water. By comparing the

decrease in trapped CO2 gas at the first and second dissolution

stage in Fig. 8, we found that most of the remaining trapped

CO2 gas was located in a relatively isolated pore. At the first

dissolution stage, the trapped CO2 was in multi-pores size.

However, at the second dissolution stage, the remaining

trapped CO2 were single-pore bubbles surrounded by granular

particles and only small possible entrances for the flowing

water. Therefore, this observation supports our theory on the

generation of the local high solute region surrounding the

trapped phase due to rapid dissolution.

5. Conclusions

Experiments of dissolution mass transfer of trapped

phase into moving water have been conducted with Ar, O2, N2,

and CO2 gases. The observation was performed with a micro-

tomography technique and was combined with image processing

techniques. The trapped gas inside the porous media was able to

be identified, and the volume and interfacial area can be derived.

As a result, the dissolution process can be investigated, and the

mass transfer coefficient can be calculated.

The dissolution behavior of CO2 gas was found to be

unique compared with Ar, O2, and N2 gases. In the case of CO2,

the dissolution process occurred in two stages, whereas Ar, O2,

and N2 gases occurred in one stage only. In addition, the mass

transfer coefficient of CO2 gas was one order of magnitude

lower than Ar, O2, and N2 gases. Because the specific interfacial

area and Schmidt number among these gases are similar, this

unique dissolution behavior should be caused by other reasons.

We believe that this unique behavior was related to the

rapid dissolution of CO2 due to the high dissolution ratio

compared with other gases (25–50 times larger). This rapid

dissolution process could have generated a high solute CO2

concentration region surrounding the trapped gas that bog down

the mass transfer rate. Because the dissolution rate of Ar, O2,

and N2 gases was not as rapid as CO2 gas, this phenomenon did

not occur in the case of Ar, O2, and N2 gases. This hypothesis

was also supported by the evidence from the micro-CT image in

Fig. 8 that most of the remaining trapped CO2 gas was left in an

isolated pore surrounded by granular particles and only a small

possible entrance for the flowing water. However, additional

investigation is still required to elucidate this hypothesis. We

are, currently, designing experiments by using micromodel

to control the dissolution process and investigate this CO2

dissolution behavior.

This unique behavior of CO2 could give implications in

geological carbon sequestration, especially related to solubility

trapping1). The progress in solubility trapping could be much

slower than expected due to the unique dissolution behavior

of CO2, especially as represented by the lower mass transfer

coefficient in this result. However, because the CO2 in GCS is in

a supercritical state, we planned to conduct further experiments

in supercritical CO2 to reassure the process. Nevertheless, a

report by Chang et al.2) has shown a similar tendency in the

dissolution of supercritical CO2 with this behavior. However,

because of the limitation in the measurement technique, they

cannot observe the spatial distribution of CO2 in the porous

medium.

Acknowledgment　　This work was supported by JSPS

KAKENHI with grant numbers 17H00790 and 20J14975.

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Fig.8　 The trapped CO2 gas at initial condition (left) and 3.25 minutes (right) demonstrated the changes of trapped bubbles from multi-pores to single-pore located in isolated pores.

Vol.137, No.9, 2021




多孔質中にトラップされたCO2 の他のガス種と比較して特異な溶解挙動*

アニンディティヨ　パトモノアジ 1　　ムハンマドナシル 2　　ムハンマドアジスマハルディカ 1

雲　佘 1　　末包哲也 3

多孔質内にトラップされているガスの流動している水相への溶解

は二酸化炭素地下貯留（GCS）などの様々な水理学的分野におい

て重要な過程である。GCS では，CO2 の溶解により，貯留層圧

力変化や浮力によるリークリスクの低減につながるため溶解速

度は安全性評価において重要な観点になる。本研究では CO2, O2,

N2, と Ar の４種のガスの多孔質中での溶解プロセスの違いを比

較検討した。CO2 は他のガスに比べて極めて特徴的な溶解挙動を

示すことを見出した。CO2 は他のガスに比べて溶解度が一桁程度

大きいため，初期の溶解が非常に速く，トラップされた CO2 気

泡の周りに飽和水の膜が形成される。この飽和膜の存在が CO2

の物質輸送係数を低下させていると考えられる。

*2019 年 12 月 18 日受付　2021 年 7 月 12 日受理1. 博士課程東京工業大学工学院機械系2. 修士課程東京工業大学工学院機械系3. 正会員東京工業大学工学院機械系教授[ 著者連絡先 ] E-mail: [email protected]キーワード：多孔質，溶解，二酸化炭素，物質輸送係数，

マイクロトモグラフィー

Vol.137, No.9, 2021

journal of mmij

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