Mass transfer between bubbles and seawater

Major CO2 blowouts from offshore wells are strongly attenuated in water deeper than 50 m

“…The mass transfer coefficient is calculated in TAMOC for the conditions of the CO 2 blowout case considered here by the correlations of Clift et al . (table 5.4, p. 123) resulting in a mass transfer coefficient of approximately 1 × 10 −4 m s –1 for the median bubble size (0.5 mm, see Results section), in excellent agreement with other correlation summaries for dirty bubbles . This mass transfer coefficient is only weakly dependent on bubble size for the blowout release conditions considered here, decreasing by about 20% as bubble size increases over its range from 0.1 to 1 mm (see Results section).…”

“…10 We can also demonstrate this by looking at Eqn (10), which we can rearrange to roughly approximate the time it takes for a CO 2 bubble to dissolve (11) where the approximate mass transfer coefficient for CO 2 in water is 1 × 10 −4 m s -1 for bubbles of diameter 0.5 mm as estimated by correlations for contaminated (i.e., dirty) bubbles. 54 If we look at the median size bubble (0.5 mm) and assume the ambient CO 2 concentration (C i eq ) is negligible relative to the CO 2 concentration in the seawater in the seawater skin of the gas-bubble interface (C s,i ), which is equal to the solubility of CO 2 in seawater assuming pure CO 2 gas CM Oldenburg and L Pan Original Research Article: Major CO 2 blowouts from offshore wells fills the bubble at the local water column pressure (C s,i = 2.62 kg CO 2 m -3 seawater for the 10-m-deep blowout and C s,i = 7.83 kg CO 2 m -3 seawater for the 50-m-deep blowout using published solubility values 68 ), we find the time to dissolve the bubble is 1.14 s. It turns out this time to dissolve is independent of depth over the 10-50 m depth range because both the mass of CO 2 in the bubble (numerator in Eqn (11)) and the dissolved CO 2 at the bubble interface (in the denominator in Eqn (11)) scale almost linearly with depth at shallow depths (more mass in bubble at larger depth because gas density is higher, but also higher solubility in seawater at greater depth). In deep water conditions, nonideal effects of CO 2 would likely arise altering this balance between density and solubility increase.…”

The Bubble Shape in Contaminated Bubbly Flows: Results for Different NaCl Concentrations in Purified Water

“…Since the present work is focusing on electrolytes, specifically NaCl, added to water, a particular application is also the emergency cooling of nuclear power reactors with seawater as was done in the Daiichi accident near Fukushima in 2011 after an earthquake (e.g., [20]). In general, also a link to previous deep-sea studies could be drawn [16,[21][22][23]. One conclusion out of these studies is that the average bubble rise-velocity is not distinctly affected.…”

Observations of Rising Methane Bubbles in Trondheimsfjord and Its Implications to Gas Dissolution

“…Due to this, a mass transfer correlation for partly contaminated conditions is widely used in models for bubble plumes in the ocean. The more recent observations made by Olsen et al () support the use of correlations for contaminated conditions, not partly contaminated. The main differences between these experiments are the geographical location and depth of the seawater and the bubble size.…”

“…This experiment was later repeated at depths down to 1,500 m (Rehder et al, ). Recently, Olsen et al () performed experiments in a downward flowing column with seawater pumped in to the lab from a depth of 70 m. There are other experiments/observations below the hydrate stability limit (e.g., Rehder et al, ; Wang et al, ). In these data there are the combined complexity of hydrates and the issue of choice of mass transfer coefficient, but some good observations can be extracted.…”