scholarly journals Oxygen gas transfer through oak barrels: a macroscopic approach

OENO One ◽  
2021 ◽  
Vol 55 (3) ◽  
pp. 53-65
Author(s):  
Rémy Junqua ◽  
Liming Zeng ◽  
Alexandre Pons

The oak barrel maturation step is nowadays strongly rooted in the production of quality wines. Two main physico‑chemical phenomena contribute to the modification and improvement of wine: the solubilisation of volatile and non-volatile wood compounds concomitant with the dissolution of oxygen from the air into the wine. Indeed, wood is a porous material and gas transfer (especially oxygen transfer, expressed as oxygen transfer rate or OTR) through oak barrels, is an intrinsic parameter which ensures wine oxygen supply during maturation. Due to its oenological impact, it has been actively studied over recent decades using several approaches based on the same principle: the monitoring of oxygen in a model wine solution in the barrel. This project aimed at assaying barrel OTR by using a new tool based on the theoretical knowledge of gas transfer through porous materials. An oxygen concentration gradient was created on each side of a barrel kept in an airtight stainless-steel tank. The concentration of the oxygen in the atmosphere around the barrel was monitored in order to quantify oxygen transfer, thus the avoiding common drawbacks of interactions between dissolved oxygen ingress kinetics and the consumption of oxygen in the liquid phase by wood components. This study reports for the first time, the diffusion coefficient of entire oak barrels (Q. sessilis) to be between 10-10 and 10-9 m²/s, and it contributes to increasing knowledge on the complex phenomena driving oxygen ingress during the maturation of wine in barrels kept in cellar conditions. The results highlight the important role of wood moisture content in oxygen transfer, and provides a simple and reliable parameter to monitor it: the weight of the barrel. Following methodology developed by the authors, the OTR of a new oak barrel was found to be 11.4 mg/L per year. Taking into account the oxygen released through the wood pores, a new barrel will contribute 14.4 mg/L per year of oxygen to the wine, of which 46 % in the first three months of aging.

OENO One ◽  
2018 ◽  
Vol 52 (1) ◽  
Author(s):  
Yang Qiu ◽  
Soizic Lacampagne ◽  
Marie Mirabel ◽  
Martine Mietton-Peuchot ◽  
Rémy Ghidossi

During wine aging, several complex phenomena take place in barrels according to oak’s intrinsic physical properties. This research aims to better understand oxygen desorption and oxygen transfer phenomena through oak staves and especially through stave gaps in order to reevaluate the importance of barrel-making in barrel’s oxygen supply. Experimentation was based on the development of an innovative permeameter. With this permeameter, we could estimate gas transfer through oak staves and between oak stave gaps. With a specially developed tightening system, the existing pressure at stave gaps in a barrel could be reproduced on a laboratory scale in order to estimate its influence on oxygen transfer efficiency. Results proved that oxygen transfer through intact oak wood is limited; the main oxygen transfer takes place (i) through weak zones caused by fragile contact between staves and (ii) with low pressure between two staves (mainly in the middle of the side pieces). So, it is identified that oxygen transfer through stave gaps is largely impacted by applied pressure and by contact conditions on the surfaces of adjacent staves. This research also proves that oxygen desorption plays an important part in total oxygen ingress. These results confirm that the barrel-making process has a strong impact on a barrel’s oxygen supply during the aging process.


2008 ◽  
Vol 7 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Dan Cascaval ◽  
Anca-Irina Galaction ◽  
Stefanica Camarut ◽  
Radu Z. Tudose

1996 ◽  
Vol 34 (3-4) ◽  
pp. 413-420
Author(s):  
Y. C. Liao ◽  
D. J. Lee

Transient model of oxygen transfer rate in a sequencing batch reactor is derived and solved numerically. The dissolved oxygen response under several conditions is analyzed. Effects of operational parameters and liquid bath height are studied. When with short, intermittent aeration periods, the transient effects on oxygen transfer rate may be substantial and should be taken into considerations. An example considering bioreaction is also given.


Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.


1993 ◽  
Vol 28 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Y. Suzuki ◽  
S. Miyahara ◽  
K. Takeishi

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.


2004 ◽  
Vol 127 (3) ◽  
pp. 400-415 ◽  
Author(s):  
Amador M. Guzmán ◽  
Rodrigo A. Escobar ◽  
Cristina H. Amon

Computational investigations of flow mixing and oxygen transfer characteristics in an intravenous membrane oxygenator (IMO) are performed by direct numerical simulations of the conservation of mass, momentum, and species equations. Three-dimensional computational models are developed to investigate flow-mixing and oxygen-transfer characteristics for stationary and pulsating balloons, using the spectral element method. For a stationary balloon, the effect of the fiber placement within the fiber bundle and the number of fiber rings is investigated. In a pulsating balloon, the flow mixing characteristics are determined and the oxygen transfer rate is evaluated. For a stationary balloon, numerical simulations show two well-defined flow patterns that depend on the region of the IMO device. Successive increases of the Reynolds number raise the longitudinal velocity without creating secondary flow. This characteristic is not affected by staggered or non-staggered fiber placement within the fiber bundle. For a pulsating balloon, the flow mixing is enhanced by generating a three-dimensional time-dependent flow characterized by oscillatory radial, pulsatile longitudinal, and both oscillatory and random tangential velocities. This three-dimensional flow increases the flow mixing due to an active time-dependent secondary flow, particularly around the fibers. Analytical models show the fiber bundle placement effect on the pressure gradient and flow pattern. The oxygen transport from the fiber surface to the mean flow is due to a dominant radial diffusion mechanism, for the stationary balloon. The oxygen transfer rate reaches an asymptotic behavior at relatively low Reynolds numbers. For a pulsating balloon, the time-dependent oxygen-concentration field resembles the oscillatory and wavy nature of the time-dependent flow. Sherwood number evaluations demonstrate that balloon pulsations enhance the oxygen transfer rate, even for smaller flow rates.


2003 ◽  
Vol 46 (3) ◽  
pp. 455-459 ◽  
Author(s):  
Georgina L. Michelena ◽  
Aidín Martínez ◽  
Antonio Bell ◽  
Emilia Carrera ◽  
Roxana Valencia

Fed batch fermentation was carried out for the dextransucrase enzyme production from Leuconostoc mesenteroides and the production was scale-up using oxygen transfer criteriuom. It was found that in 5 L vessel fermentation capacity, the best agitation speed was 225 min-1 and aeration rate was 0.15 vvm, obtaining dextransucrase activity of 127 DSU/mL.. The maximum enzyme production velocity coincide with the maximum growth velocity between 6 and 7 h of fermentation, which confirmed that dextransucrase production was associated with microbial growth. High enzyme yields were achieved during scale up based on oxygen transfer rate.


1994 ◽  
Vol 16 (12) ◽  
pp. 1074-1078 ◽  
Author(s):  
Francisco M. Gírio ◽  
J.Carlos Roseiro ◽  
Pascolina Sá-Machado ◽  
A.Rita Duarte-Reis ◽  
M.T. Amaral-Collaço

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