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Concentrating orange juice through CO2 clathrate hydrate technology
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Concentrating orange juice through CO2 clathrate hydrate technology Shifeng Li a,b,∗ , Yanming Shen b , Dongbing Liu b , Lihui Fan b , Zhe Tan b a
Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China b College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China
a b s t r a c t A novel separation process was developed for orange juice concentration via CO2 hydrate formation. The CO2 hydrate equilibrium conditions were measured by an isochoric pressure search method. The effects of feed pressure, temperature, juice volume, and stirring speed on dehydration ratio were investigated. The dehydration ratio increased with increasing the feed pressure; the maximum dehydration ratio of 57.2% was reached at feed pressure of 4.10 MPa; dehydration ratio maintained around 45.8% in the temperature range of 274.8–279.8 K; the optimum orange juice volume is 80 mL. The CO2 hydrate formation rate constants increased from 0.67 × 10−8 to 1.91 × 10−8 mol2 /(s J) in relation to the feed pressure increasing from 1.96 to 4.10 MPa. The results demonstrated that removal of water by formation of CO2 hydrate is an efficient technology for orange juice concentration. © 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords: Clathrate hydrate; Concentration; Separation; CO2 ; Orange juice; Dehydration ratio
1.
Introduction
To reduce packaging, storage and transport cost, fruit juices are usually subjected to concentration. Many efforts have been devoted to develop improved methods such as evaporation, membranes (ultrafiltration, reverse osmosis and membrane distillation), and freeze concentration for concentrated juice processing (Jiao et al., 2004; Cassano et al., 2011; Jesus et al., 2007; Guignon et al., 2012; Aider and de Halleux, 2008). The traditional technique used for concentration of liquid foods is evaporation. However, a more efficient evaporation process is required under boiling conditions at higher temperatures to avoid possible loss and/or damage of volatile or heat-sensitive molecules such as polyphenols and vitamin C (Jiao et al., 2004; Guignon et al., 2012). Though membrane concentration is also regarded as one of the potential alternative technologies (Jiao et al., 2004; Cassano et al., 2011; Jesus et al., 2007), these membranes will become dirty as the product is concentrated and its viscosity increase (Guignon et al., 2012). Frequent cleaning is necessary to obtain good quality which will increase
production cost and time (Aider and de Halleux, 2008). For the third method, freeze concentration, concentrate quality is satisfactory but it also consumes a lot of energy, especially during the ice nucleation step (Guignon et al., 2012). Recently, hydrate separation technology has attracted scientific interest in the fields of CO2 capture (Nguyen Hong et al., 2007; Wang et al., 2013; Eslamimanesh et al., 2012; Fan et al., 2009; Li et al., 2009; Tajim et al., 2014; Gholinezhad et al., 2011; Tang et al., 2013), hydrogen or methane recovery (Liu et al., 2014; Zhong and Englezos, 2012; Sun et al., 2011) and desalination (Javanmardi and Moshfeghian, 2003; Park et al., 2011). Hydrates (also called clathrate hydrates) are nonstoichiometric crystalline inclusion compounds form through the combination of water and suitably sized “guest” molecules, typically under low temperature and elevated pressure conditions (Sloan and Koh, 2008). In gas hydrates, water molecules form a lattice structures with several interstitial cavities (Sloan and Koh, 2008; Englezos, 1993). The basic principle of aqueous concentration by gas hydrate is that under suitable conditions both temperature and pressure; the gas forms hydrate which
∗
Corresponding author at: Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China. Tel.: +86 24 89383902; fax: +86 24 89383760. E-mail address: [email protected] (S. Li). http://dx.doi.org/10.1016/j.cherd.2014.07.020 0263-8762/© 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Please cite this article in press as: Li, S., et al., Concentrating orange juice through CO2 clathrate hydrate technology. Chem. Eng. Res. Des. (2014), http://dx.doi.org/10.1016/j.cherd.2014.07.020
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can be removed from the concentrated solution by mechanical separation. Consequently, the resulting gas hydrate is decomposed by elevating the temperature or by reducing the pressure to yield the gas and water. Concentration process by gas hydrate is similar to freeze concentration in which only the ice formation step is replaced by gas hydrate crystal formation step during gas hydrate concentration. Because gas hydrate can be formed above 0 ◦ C, if the hydrate formation pressure is moderate, energy consumption in hydrate concentration would be competitive with that in freezing (Wang et al., 2013; Fan et al., 2009; Li et al., 2009). Despite recent advances in hydrate separation technology, there is little report on aqueous concentration via hydrate formation (Ngan and Englezos, ˘ 1996; Chun et al., 2005; Aydogan et al., 2007; Bayraktar et al., 2008), especially in application in juice concentration (Huang et al., 1996, Purwanto et al., 2011, Andersen and Thomsen, 2009). In fact, as early as the 1960s, Huang et al. (1996) utilized CH3 Br and CCl3 F hydrate to concentrate apple, orange, and tomato juices. No difficulty was encountered in removing approximately 80% of the water from the substrates. However, the concentration process diminished the color and flavor of most substances, and frequently imparted a slightly bitter after taste. Because the hydrate gas is not environmental friendly, the practical use of juice concentration by CH3 Br and CCl3 F hydrate formation is limited. In the following 40 years there is no report on fruit juice concentration via gas hydrate formation. Until 2001, Purwanto et al. (2011) carried out study on concentration of coffee solutions by using xenon hydrate. They determined the induction time and size distribution of gas hydrate and found that longer time was required for higher concentration of solution to form xenon hydrate and higher temperature and lower xenon pressure yielded the larger size of xenon hydrate. Andersen and Thomsen (2009) investigated the possibility of gas hydrates for concentration of sugar juice. It was found that the process is not suitable for sugar production, but could be interesting for concentration of heat sensitive, high value products. To the best of our knowledge, there is no report on orange juice concentration via formation of CO2 hydrate and how the hydrate formation conditions affect separation efficiency is not clear. The purpose of this work is to develop a novel orange juice concentration method via CO2 hydrate formation and investigate the effect of feed pressure, temperature, volume of juice and stirring speed on the concentration efficiency in order to establish the optimum operating conditions and to explore the possible practical applications of the technique in the future.
2.
Materials and methods
2.1.
Materials
CO2 gas (99.99%) was purchased from Beijing AP BAIF Gases Industry CO., Ltd (China) and orange juice was supplied by Beijing Huiyuan Group (China). The contents of reducing sugars, total acid, vitamin C, soluble solid and water content of orange juice are listed in Table 1.
2.2.
Feiyu Science and Technology exploitation CO., China). The reactor can be operated at pressure up to 25 MPa. The reactor was submerged into a thermostat (Tianheng THCD-306) with a stability of ±0.01 K to control the temperature. Two Pt-100 resistance thermometers (Westzh WZ-PT100) within 0.1 K accuracy placed in the middle and bottom of the reactor respectively were used to monitor the temperature of the reactor. A pressure transducer (Senex DG-1300) with the accuracy of 0.01 MPa was used to measure the pressure inside the reactor. The pressures and temperatures of the reactor were recorded by data logger (Agilent 34972A).
2.3.
CO2 hydrate phase equilibrium
The hydrate equilibrium conditions were measured by an isochoric pressure search method (Li et al., 2010; Tohidi et al., 2000). The reactor containing liquids (approximately 120 mL) was immersed into the temperature-controlled bath. CO2 gas was then supplied from gas cylinder through a pressureregulating valve into the evacuated cell until the pressure inside the cell was increased to the desired level. After temperature and pressure leveling off, the valve in the line connecting the cell and cylinder was closed, and then the stirrer was started. Subsequently, temperature was gradually decreased to form the hydrate. Hydrate formation in the cell was detected by a decrease in pressure and an increase in temperature. The temperature was then increased with steps of 0.1 K. At every temperature step, the temperature was held constant for 4 h to achieve equilibrium state in the cell. In this way, a P–T diagram was obtained for each experimental run, from which the hydrate dissociation point was determined (Imai et al., 2005; Ohmura et al., 2006). Consequently, the point at which the slope of the P–T curve plots sharply changed was considered as the hydrate dissociation point at which all hydrate crystals have dissociated.
2.4.
Orange juice hydrate concentration experiment
After 100 mL orange juice solution was introduced into the evacuated reactor, the reactor was cooled to the desired value (typical at 275.8 K). When the cell temperature was stabilized, the reactor was vacuumed to ensure the absence of air, and then CO2 was charged into cell up to the given pressure. Then the stirrer was started to initiate hydrate formation (500 rpm). During experiment the temperature and pressure were recorded. After hydrate formation completing (the system pressure was stable), the stirrer was stopped.
2.5.
The molar number of gas consumed
The molar number of gas that has been consumed during hydrate formation can be calculated as follows Eq. (1) (8):
n = nf − ne =
Pf Vg zf RT
−
Pe Vg ze RT
(1)
Apparatus
The basic experimental setup was adopted from Li et al. (2010) with modifications to facilitate the higher pressure applications. It mainly consisted of a stainless-steel reactor (volume 300 mL) equipped with a magnetic stirrer (Nantong
where z is the compressibility factor calculated by SRK equation of state, subscripts f, e refer to the feed gas and equilibrium gas. The volume of gas was assumed constant throughout the hydrate formation process (volume changes due to the phase transitions were neglected).
Please cite this article in press as: Li, S., et al., Concentrating orange juice through CO2 clathrate hydrate technology. Chem. Eng. Res. Des. (2014), http://dx.doi.org/10.1016/j.cherd.2014.07.020
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Table 1 – The contents of reducing sugars, total acid, vitamin C, soluble solid and water content of orange juice used in this work. Orange juice
Reducing sugar (g/100 g)
Total acid (g/kg)
Vitamin C (mg/100 g)
Soluble solid
Water cut
4.42
6.08
49.96
10.5%
87.7%
Content
2.6.
Dehydration ratio
The content of water in hydrate phase is important for evaluating the dehydrate ratio of CO2 (defined as ratio of water in the hydrate phase and in the feed orange juice). Because it is difficult to directly determine the water cut in hydrate phase in the presence of residual concentrate orange juice, the following assumption CO2 “reacts” with water to form CO2 hydrate based on following reaction Eq. (2) were adapted. CO2 (g) + nH2 O(l) → CO2 ·nH2 O(H)
n × n × WH2 O × 100% mf
(3)
where, WH2 O is molar mass of water, and mf is the mass of water in feed orange juice.
2.7.
Hydrate formation rate constant
−
dt
Vg (ff − fe ) 2 (RT) t × ln(ff /fe )
3.
Results and discussion
3.1.
CO2 hydrate phase equilibrium conditions
(8)
= aK∗ (f − e )
(4)
1 1 1 = − K∗ kf kL
The hydrate formation conditions for CO2 were measured in the presence of pure water and orange juice and the results were shown in Fig. 1. From Fig. 1, it can be clearly seen that the CO2 hydrate equilibrium curve in the presence of orange juice slightly shifts to higher pressure and lower temperature. Therefore, it can be concluded that the orange juice has little effect on CO2 hydrate formation because the most component of orange juice (87.7 wt%) is water and the residuals (fructose and soluble solid) have slight impact on equilibrium temperature and pressure of CO2 hydrate formation (Andersen and Thomsen, 2009).
3.2.
The hydrate formation rate can be expressed in terms of fugacity difference during formation and at equilibrium (Englezos et al., 1987; Daimaru et al., 2007). In this work, the chemical potential difference was used as the driving force and the apparent gas uptake rate (−dn/dt) is expressed as Eqs. (4) and (5):
dn
akf =
(2)
where n is the hydrate number of CO2 hydrate, according to ˘ (1963) theoretical calculations result of McKov and Sinanoglu and Raman spectroscopic analyses data of Uchida et al. (1995), the hydrate number of CO2 hydrate (n) under this work is approximately equal to 7.24. Therefore, the dehydrate ratio (D) can be calculated as following Eq. (3): D=
of the gas phase and t is the time to reach equilibrium for hydrate separation process. Due to it is difficult to separate the terms a and kf from the experimental results for the fugacity change, the hydrate rate constant expressed as Eq. (8):
(5)
CO2 hydrate concentration experiment
Fig. 2 shows the typical CO2 gas uptake curves for a period of 150 min. The general shape of this curve agrees with the gas uptake curve described in detail by reference literatures (Li et al., 2009). As the feed pressure increased from 1.96 to 4.10 MPa, the CO2 gas uptake increased from 0.108 to 0.385 mol, and the needed time to equilibrium state decreased, which was attribute to the reason that more gas was enclosed into hydrate under higher feed pressure. All of these indicate that higher feed pressure is benefit to more hydrate formation and higher hydrate rate.
where a is the interfacial area, K∗ is the overall kinetic constant, f and e are chemical potentials of the guest molecule in the gas phase and in the hydrate phase, respectively, kf is the crystal growth constant, kL is the mass transfer coefficient in the liquid phase. Under the conditions of this study, 1/kL could be eliminated by a vigorous stirring (500 rpm) in the reactor (1/kf 1/kL ). So the hydrate rate can be expressed by Eqs. (6) and (7): rf =
rf =
dn −
dt
n t
= akf (f − e ) = akf RT ln
=
Vg (ff − fe ) RT t
ff fe
(6)
(7)
where ff and fe are the fugacity of the gas phase and the hydrate phase at equilibrium condition, respectively, calculated by SRK equation of state, and fe is assumed to be not strongly affected by dehydration process, Vg is the volume
Fig. 1 – Hydrate phase equilibrium conditions for CO2 + water and CO2 + orange juice systems.
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Fig. 2 – CO2 consumption curve for hydrate formation in the presence of orange juice at 275.8 K from 1.96 MPa to 4.10 MPa.
3.3.
Effect of feed pressure
Firstly, the orange juice concentration experiment was carried out with different feed pressure. In this work, a range of 1.96–4.10 MPa for feed pressure was examined. Fig. 3 shows the result on dehydration ratio as function feed pressure. As shown in Fig. 3, the dehydration ratio calculated according Eq. (3) increased with the feed pressure increasing from 1.96 to 4.10 MPa. The maximum dehydration ratio can reach 57.2% at feed pressure of 4.10 MPa. It is consistent with the trend of CO2 uptake accompanying with feed pressure increasing. These results clearly indicate that CO2 feed pressure plays a key role on the orange concentration by hydrate formation. However, although higher feed pressure was more benefit to concentration efficiency, the higher feed pressure would also need higher compression work.
3.4.
Fig. 4 – Effect of temperature on orange juice dehydration ratio at feed pressure of 3.72 MPa.
Effect of temperature
would need higher refrigeration energy consumption. Comparing with the results of Figs. 3 and 4, the effect of feed pressure on dehydration ratio is more obvious than that of temperature.
3.5.
Effect of orange juice volume
The orange juice concentration process was also carried out with different orange juice volumes at 275.8 K and 3.72 MPa. As shown in Fig. 5, dehydration ratio reached a maximum of 59.5% at the orange juice volume of 60 mL. And with the increase orange juice volume, the mass of removed water accordingly increases. Therefore, on the basis of the above results obtained, the optimum orange juice volume is 80 mL.
3.6.
Effect of stirring speed
The effect of hydrate formation temperature on dehydration ratio was also studied. Fig. 4 shows dehydration ratio as a function of temperature at the feed pressure of 3.72 MPa. It can be seen that dehydration ratio varied from 41.9% to 45.8% in the temperature range of 274.8–279.8 K. The dehydration ratio reached maximum with the lower temperature, which may be attributed to the fact that lower temperature is beneficial to hydrate formation. However, the lower temperature also
The effect of stirring speed on dehydration ratio is given in Fig. 6. It can be seen that the dehydration ratios were about 43% with stirring speed from 400 to 800 rpm at 275.8 K and 3.72 MPa. The result clearly indicated that stirring speed almost has no effect on dehydration ratio. Though the stirring speed is different, the driving force of hydrate formation which is the pressure and temperature differential to equilibrium state is the same.
Fig. 3 – Effect of feed pressure on orange juice dehydration ratio at 275.8 K.
Fig. 5 – Effect of orange juice volume on orange juice dehydration ratio at 275.8 K and 3.72 MPa.
Please cite this article in press as: Li, S., et al., Concentrating orange juice through CO2 clathrate hydrate technology. Chem. Eng. Res. Des. (2014), http://dx.doi.org/10.1016/j.cherd.2014.07.020
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Acknowledgments This research was funded by the National Natural Science Foundation of China (No. 21106085) and Supported by Program for Liaoning Excellent Talents in University (No. LJQ2014042).
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.cherd.2014.07.020.
Fig. 6 – Effect of stirring speed on orange juice dehydration ratio at 275.8 K and 3.72 MPa.
Table 2 – Results for the hydrate formation rate constant. Pressure (MPa)
akf ( × 10–8 mol2 /(s J))
1.96 2.70 3.20 3.72 4.10
3.7.
0.67 0.97 1.34 1.62 1.91
Hydrate formation rate constant
As shown in Table 2, the hydrate formation rate constants calculated using Eq. (8) were 0.67 × 10−8 mol2 /(s J), 0.97 × 10−8 mol2 /(s J), 1.34 × 10−8 mol2 /(s J), −8 2 −8 1.62 × 10 mol /(s J) and 1.91 × 10 mol2 /(s J) with the feed pressure of 1.96 MPa, 2.70 MPa, 3.20 MPa, 3.72 and 4.10 MPa, respectively. The results showed that the hydrate formation constants were in the same order magnitude as the results of CH4 hydrate (30), which were in the presence of different carbon length surfactants. Additionally, the result revealed the rate constant increased with the increase of the feed pressure. It can be explained by the fact that higher driving force was got at higher feed pressure which was consistent with two-film model for hydrate formation process (Englezos et al., 1987; Daimaru et al., 2007).
4.
Conclusion
1) The hydrate phase equilibrium results show that comparing to pure water, the CO2 hydrate formation condition slight shifts to higher pressure and lower temperature in presence of orange juice in which water cut was about 87.7%. 2) The dehydration ratio increased with increasing the feed pressure from 1.96 to 4.10 MPa; the maximum dehydration ratio of 57.2% was reached at feed pressure of 4.10 MPa; dehydration ratio increased from 41.9% to 45.8% in the temperature range of 274.8–279.8 K; the optimum orange juice volume is 80 mL; the stirring speed nearly has no effect on dehydration ratio. 3) The CO2 hydrate formation rate constants increased with the increasing feed pressure ranging from 1.96 to 4.10 MPa. The CO2 hydrate formation constants in this work were in the same order magnitude as the results of CH4 hydrate in the presence of surfactants.
References Aider, M., de Halleux, D., 2008. Production of concentrated cherry and apricot juices by cryoconcentration technology. LWT-Food Sci. Technol. 41, 1768–1775. Andersen, T.B., Thomsen, K., 2009. Separation of water through gas hydrate formation. Int. Sugar J. 111, 632–636. ˘ ˘ Aydogan, Ö., Bayraktar, E., Parlaktuna, M., Mehmetoglu, T., ˘ Mehmetoglu, Ü., 2007. Production of l-aspartic acid by biotransformation and recovery using reverse micelle and gas hydrate methods. Biocatal. Biotransform. 25, 365–372. ˘ Bayraktar, E., AKocapic¸ak, Ö., Mehmetoglu, Ü., Parlaktuna, M., ˘ Mehmetoglu, T., 2008. Recovery of amino acids from reverse micellar solution by gas hydrate. Chem. Eng. Res. Des. 86, 209–213. Cassano, A., Conidi, C., Drioli, E., 2011. Clarification and concentration of pomegranate juice (Punica granatum L.) using membrane processes. J. Food Eng. 107, 366–373. Chun, B.S., Park, S.Y., Kang, K.Y., 2005. Extraction of lysozyme using reverse micelles and pressurized carbon dioxide. Sep. Sci. Technol. 40, 2497–2508. Daimaru, T., Yamasaki, A., Yanagisawa, Y., 2007. Effect of surfactant carbon chain length on hydrate formation kinetics. J. Pet. Sci. Eng. 56, 89–96. Englezos, P., 1993. Clathrate hydrates. Ind. Eng. Chem. Res. 32, 1251–1274. Englezos, P., Kalogerakis, N., Dholabhaiand, P.D., Bishnoi, P.R., 1987. Kinetics of formation of methane and ethane gas hydrates. Chem. Eng. Sci. 42, 2647–2658. Eslamimanesh, A., Mohammadi, A.H., Richon, D., Naidoo, P., Ramjugernath, D., 2012. Application of gas hydrate formation in separation processes, a review of experimental studies. J. Chem. Thermodyn. 46, 62–71. Fan, S., Li, S., Wang, J., Lang, X., Wang, Y., 2009. Efficient capture of CO2 from simulated flue gas by formation of TBAB or TBAF semiclathrate hydrates. Energy Fuels 23, 4202–4208. Gholinezhad, J., Chapoy, A., Tohidi, B., 2011. Separation and capture of carbon dioxide from CO2 /H2 syngas mixture using semi-clathrate hydrates. Chem. Eng. Res. Design 87, 1747–1751. Guignon, B., Aparicio, C., Sanz, P.D., Otero, L., 2012. Orange juice pvT-properties for high pressure processing and modeling purposes. Food Res. Int. 46, 83–91. Huang, C.P., Fennema, O., Powrie, W.D., 1996. Gas hydrates in aqueous-organic systems. II. Concentration by gas hydrate formation. Cryobiology 2, 240–245. Imai, S., Okutani, K., Ohmura, R., Mori, Y.H., 2005. Phase equilibrium for clathrate hydrates formed with difluoromethane + either cyclopentane or tetra-n-butylammonium bromide. J. Chem. Eng. Data 50, 1783–1786. Javanmardi, J., Moshfeghian, M., 2003. Energy consumption and economic evaluation of water desalination by hydrate phenomenon. Appl. Therm. Eng. 23, 845–857. Jesus, D.F., Leite, M.F., Silva, L.F.M., Modesta, R.D., Matta, V.M., Cabral, L.M.C., 2007. Orange (Citrus sinensis) juice concentration by reverse osmosis. J. Food Eng. 81, 287–291.
Please cite this article in press as: Li, S., et al., Concentrating orange juice through CO2 clathrate hydrate technology. Chem. Eng. Res. Des. (2014), http://dx.doi.org/10.1016/j.cherd.2014.07.020
CHERD-1653; No. of Pages 6
6
ARTICLE IN PRESS chemical engineering research and design x x x ( 2 0 1 4 ) xxx–xxx
Jiao, B., Cassano, A., Drioli, E., 2004. Recent advances on membrane processes for the concentration of fruit juices, a review. J. Food Eng. 63, 303–324. Li, S., Fan, S., Wang, J., Lang, X., Liang, D., 2009. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide. J. Nat. Gas Chem. 18, 15–20. Li, S., Fan, S., Wang, J., Lang, X., Wang, Y., 2010. Semiclathrate hydrate phase equilibria for CO2 in the presence of tetra-n-butyl ammonium halide (bromide, chloride, or fluoride). J. Chem. Eng. Data 55, 3212–3215. Liu, B., Liu, H., Wang, B., Wang, J., Sun, C., Zeng, X., Chen, G., 2014. Hydrogen separation via forming hydrate in W/O emulsion. Fluid Phase Equilib. 362, 252–257. ˘ McKov, V., Sinanoglu, O., 1963. Theory of dissociation pressures of some gas hydrates. J. Chem. Phys. 38, 2946–2956. Ngan, Y.T., Englezos, P., 1996. Concentration of mechanical pulp mill effluents and NaCl solutions through propane hydrate formation. Ind. Eng. Chem. Res. 35, 1894–1990. Nguyen Hong, D., Chauvy, F., Herri, J.M., 2007. CO2 capture by hydrate crystallization - A potential solution for gas emission of steel making industry. Energy Convers. Manage. 48, 1313–1322. Ohmura, R., Takeya, S., Maekawa, T., Uchida, T., 2006. Phase equilibrium for structure-H hydrate formed with krypton and 2,2-dimethylbutane. J. Chem. Eng. Data 51, 161–163. Park, K., Hong, S.Y., Lee, J.W., Kang, K.C., Lee, Y.C., Ha, M., Lee, J.D., 2011. A new apparatus for seawater desalination by gas hydrate process and removal. Desalination 274, 91–96.
Purwanto, Y.A., Oshita, S., Seo, Y., Kawagoe, Y., 2011. Concentration of liquid foods by the use of gas hydrate. J. Food Eng. 47, 133–138. Sloan, E.D., Koh, C.A., 2008. Clathrate Hydrates of Natural Gases, third ed. CRC Press, New York. Sun, Q., Guo, X., Liu, A., Liu, B., Huo, Y., Chen, G., 2011. Experimental study on the separation of CH4 and N2 via hydrate formation in TBAB solution. Ind. Eng. Chem. Res. 50, 2284–2288. Tajim, H., Oota, Y., Yamagiwa, K., 2014. Improving the gas recovery and separation efficiency of a hydrate-based gas separation. Chem. Eng. Res. Design, http://dx.doi.org/10.1016/j.cherd.2014.02.008. Tang, J., Zeng, D., Wang, C., Chen, Y., He, L., Cai, N., 2013. Study on the influence of SDS and THF on hydrate-based gas separation performance. Chem. Eng. Res. Design 91, 1777–1782. Tohidi, B., Burgass, R.W., Danesh, A., Østergaard, K.K., Todd, A.C., 2000. Improving the accuracy of gas hydrate dissociation point measurements. Ann. N. Y. Acad. Sci. 912, 924–931. Uchida, T., Takagi, A., Kawabata, J., Mae, S., Hondoh, T., 1995. Raman spectroscopic analyses of the growth process of CO2 hydrates. Energy Convers. Manage. 36, 547–550. Wang, Y., Lang, X., Fan, S., 2013. Hydrate capture CO2 from shifted synthesis gas, flue gas. J. Energy Chem. 22, 39–47. Zhong, D., Englezos, P., 2012. Methane separation from coal mine methane gas by tetra-n-butyl ammonium bromide semiclathrate hydrate formation. Energy Fuels 26, 2098–2106.
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Concentrating orange juice through CO2 clathrate hydrate technology Shifeng Li a,b,∗ , Yanming Shen b , Dongbing Liu b , Lihui Fan b , Zhe Tan b a
Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China b College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China
a b s t r a c t A novel separation process was developed for orange juice concentration via CO2 hydrate formation. The CO2 hydrate equilibrium conditions were measured by an isochoric pressure search method. The effects of feed pressure, temperature, juice volume, and stirring speed on dehydration ratio were investigated. The dehydration ratio increased with increasing the feed pressure; the maximum dehydration ratio of 57.2% was reached at feed pressure of 4.10 MPa; dehydration ratio maintained around 45.8% in the temperature range of 274.8–279.8 K; the optimum orange juice volume is 80 mL. The CO2 hydrate formation rate constants increased from 0.67 × 10−8 to 1.91 × 10−8 mol2 /(s J) in relation to the feed pressure increasing from 1.96 to 4.10 MPa. The results demonstrated that removal of water by formation of CO2 hydrate is an efficient technology for orange juice concentration. © 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords: Clathrate hydrate; Concentration; Separation; CO2 ; Orange juice; Dehydration ratio
1.
Introduction
To reduce packaging, storage and transport cost, fruit juices are usually subjected to concentration. Many efforts have been devoted to develop improved methods such as evaporation, membranes (ultrafiltration, reverse osmosis and membrane distillation), and freeze concentration for concentrated juice processing (Jiao et al., 2004; Cassano et al., 2011; Jesus et al., 2007; Guignon et al., 2012; Aider and de Halleux, 2008). The traditional technique used for concentration of liquid foods is evaporation. However, a more efficient evaporation process is required under boiling conditions at higher temperatures to avoid possible loss and/or damage of volatile or heat-sensitive molecules such as polyphenols and vitamin C (Jiao et al., 2004; Guignon et al., 2012). Though membrane concentration is also regarded as one of the potential alternative technologies (Jiao et al., 2004; Cassano et al., 2011; Jesus et al., 2007), these membranes will become dirty as the product is concentrated and its viscosity increase (Guignon et al., 2012). Frequent cleaning is necessary to obtain good quality which will increase
production cost and time (Aider and de Halleux, 2008). For the third method, freeze concentration, concentrate quality is satisfactory but it also consumes a lot of energy, especially during the ice nucleation step (Guignon et al., 2012). Recently, hydrate separation technology has attracted scientific interest in the fields of CO2 capture (Nguyen Hong et al., 2007; Wang et al., 2013; Eslamimanesh et al., 2012; Fan et al., 2009; Li et al., 2009; Tajim et al., 2014; Gholinezhad et al., 2011; Tang et al., 2013), hydrogen or methane recovery (Liu et al., 2014; Zhong and Englezos, 2012; Sun et al., 2011) and desalination (Javanmardi and Moshfeghian, 2003; Park et al., 2011). Hydrates (also called clathrate hydrates) are nonstoichiometric crystalline inclusion compounds form through the combination of water and suitably sized “guest” molecules, typically under low temperature and elevated pressure conditions (Sloan and Koh, 2008). In gas hydrates, water molecules form a lattice structures with several interstitial cavities (Sloan and Koh, 2008; Englezos, 1993). The basic principle of aqueous concentration by gas hydrate is that under suitable conditions both temperature and pressure; the gas forms hydrate which
∗
Corresponding author at: Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China. Tel.: +86 24 89383902; fax: +86 24 89383760. E-mail address: [email protected] (S. Li). http://dx.doi.org/10.1016/j.cherd.2014.07.020 0263-8762/© 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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can be removed from the concentrated solution by mechanical separation. Consequently, the resulting gas hydrate is decomposed by elevating the temperature or by reducing the pressure to yield the gas and water. Concentration process by gas hydrate is similar to freeze concentration in which only the ice formation step is replaced by gas hydrate crystal formation step during gas hydrate concentration. Because gas hydrate can be formed above 0 ◦ C, if the hydrate formation pressure is moderate, energy consumption in hydrate concentration would be competitive with that in freezing (Wang et al., 2013; Fan et al., 2009; Li et al., 2009). Despite recent advances in hydrate separation technology, there is little report on aqueous concentration via hydrate formation (Ngan and Englezos, ˘ 1996; Chun et al., 2005; Aydogan et al., 2007; Bayraktar et al., 2008), especially in application in juice concentration (Huang et al., 1996, Purwanto et al., 2011, Andersen and Thomsen, 2009). In fact, as early as the 1960s, Huang et al. (1996) utilized CH3 Br and CCl3 F hydrate to concentrate apple, orange, and tomato juices. No difficulty was encountered in removing approximately 80% of the water from the substrates. However, the concentration process diminished the color and flavor of most substances, and frequently imparted a slightly bitter after taste. Because the hydrate gas is not environmental friendly, the practical use of juice concentration by CH3 Br and CCl3 F hydrate formation is limited. In the following 40 years there is no report on fruit juice concentration via gas hydrate formation. Until 2001, Purwanto et al. (2011) carried out study on concentration of coffee solutions by using xenon hydrate. They determined the induction time and size distribution of gas hydrate and found that longer time was required for higher concentration of solution to form xenon hydrate and higher temperature and lower xenon pressure yielded the larger size of xenon hydrate. Andersen and Thomsen (2009) investigated the possibility of gas hydrates for concentration of sugar juice. It was found that the process is not suitable for sugar production, but could be interesting for concentration of heat sensitive, high value products. To the best of our knowledge, there is no report on orange juice concentration via formation of CO2 hydrate and how the hydrate formation conditions affect separation efficiency is not clear. The purpose of this work is to develop a novel orange juice concentration method via CO2 hydrate formation and investigate the effect of feed pressure, temperature, volume of juice and stirring speed on the concentration efficiency in order to establish the optimum operating conditions and to explore the possible practical applications of the technique in the future.
2.
Materials and methods
2.1.
Materials
CO2 gas (99.99%) was purchased from Beijing AP BAIF Gases Industry CO., Ltd (China) and orange juice was supplied by Beijing Huiyuan Group (China). The contents of reducing sugars, total acid, vitamin C, soluble solid and water content of orange juice are listed in Table 1.
2.2.
Feiyu Science and Technology exploitation CO., China). The reactor can be operated at pressure up to 25 MPa. The reactor was submerged into a thermostat (Tianheng THCD-306) with a stability of ±0.01 K to control the temperature. Two Pt-100 resistance thermometers (Westzh WZ-PT100) within 0.1 K accuracy placed in the middle and bottom of the reactor respectively were used to monitor the temperature of the reactor. A pressure transducer (Senex DG-1300) with the accuracy of 0.01 MPa was used to measure the pressure inside the reactor. The pressures and temperatures of the reactor were recorded by data logger (Agilent 34972A).
2.3.
CO2 hydrate phase equilibrium
The hydrate equilibrium conditions were measured by an isochoric pressure search method (Li et al., 2010; Tohidi et al., 2000). The reactor containing liquids (approximately 120 mL) was immersed into the temperature-controlled bath. CO2 gas was then supplied from gas cylinder through a pressureregulating valve into the evacuated cell until the pressure inside the cell was increased to the desired level. After temperature and pressure leveling off, the valve in the line connecting the cell and cylinder was closed, and then the stirrer was started. Subsequently, temperature was gradually decreased to form the hydrate. Hydrate formation in the cell was detected by a decrease in pressure and an increase in temperature. The temperature was then increased with steps of 0.1 K. At every temperature step, the temperature was held constant for 4 h to achieve equilibrium state in the cell. In this way, a P–T diagram was obtained for each experimental run, from which the hydrate dissociation point was determined (Imai et al., 2005; Ohmura et al., 2006). Consequently, the point at which the slope of the P–T curve plots sharply changed was considered as the hydrate dissociation point at which all hydrate crystals have dissociated.
2.4.
Orange juice hydrate concentration experiment
After 100 mL orange juice solution was introduced into the evacuated reactor, the reactor was cooled to the desired value (typical at 275.8 K). When the cell temperature was stabilized, the reactor was vacuumed to ensure the absence of air, and then CO2 was charged into cell up to the given pressure. Then the stirrer was started to initiate hydrate formation (500 rpm). During experiment the temperature and pressure were recorded. After hydrate formation completing (the system pressure was stable), the stirrer was stopped.
2.5.
The molar number of gas consumed
The molar number of gas that has been consumed during hydrate formation can be calculated as follows Eq. (1) (8):
n = nf − ne =
Pf Vg zf RT
−
Pe Vg ze RT
(1)
Apparatus
The basic experimental setup was adopted from Li et al. (2010) with modifications to facilitate the higher pressure applications. It mainly consisted of a stainless-steel reactor (volume 300 mL) equipped with a magnetic stirrer (Nantong
where z is the compressibility factor calculated by SRK equation of state, subscripts f, e refer to the feed gas and equilibrium gas. The volume of gas was assumed constant throughout the hydrate formation process (volume changes due to the phase transitions were neglected).
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Table 1 – The contents of reducing sugars, total acid, vitamin C, soluble solid and water content of orange juice used in this work. Orange juice
Reducing sugar (g/100 g)
Total acid (g/kg)
Vitamin C (mg/100 g)
Soluble solid
Water cut
4.42
6.08
49.96
10.5%
87.7%
Content
2.6.
Dehydration ratio
The content of water in hydrate phase is important for evaluating the dehydrate ratio of CO2 (defined as ratio of water in the hydrate phase and in the feed orange juice). Because it is difficult to directly determine the water cut in hydrate phase in the presence of residual concentrate orange juice, the following assumption CO2 “reacts” with water to form CO2 hydrate based on following reaction Eq. (2) were adapted. CO2 (g) + nH2 O(l) → CO2 ·nH2 O(H)
n × n × WH2 O × 100% mf
(3)
where, WH2 O is molar mass of water, and mf is the mass of water in feed orange juice.
2.7.
Hydrate formation rate constant
−
dt
Vg (ff − fe ) 2 (RT) t × ln(ff /fe )
3.
Results and discussion
3.1.
CO2 hydrate phase equilibrium conditions
(8)
= aK∗ (f − e )
(4)
1 1 1 = − K∗ kf kL
The hydrate formation conditions for CO2 were measured in the presence of pure water and orange juice and the results were shown in Fig. 1. From Fig. 1, it can be clearly seen that the CO2 hydrate equilibrium curve in the presence of orange juice slightly shifts to higher pressure and lower temperature. Therefore, it can be concluded that the orange juice has little effect on CO2 hydrate formation because the most component of orange juice (87.7 wt%) is water and the residuals (fructose and soluble solid) have slight impact on equilibrium temperature and pressure of CO2 hydrate formation (Andersen and Thomsen, 2009).
3.2.
The hydrate formation rate can be expressed in terms of fugacity difference during formation and at equilibrium (Englezos et al., 1987; Daimaru et al., 2007). In this work, the chemical potential difference was used as the driving force and the apparent gas uptake rate (−dn/dt) is expressed as Eqs. (4) and (5):
dn
akf =
(2)
where n is the hydrate number of CO2 hydrate, according to ˘ (1963) theoretical calculations result of McKov and Sinanoglu and Raman spectroscopic analyses data of Uchida et al. (1995), the hydrate number of CO2 hydrate (n) under this work is approximately equal to 7.24. Therefore, the dehydrate ratio (D) can be calculated as following Eq. (3): D=
of the gas phase and t is the time to reach equilibrium for hydrate separation process. Due to it is difficult to separate the terms a and kf from the experimental results for the fugacity change, the hydrate rate constant expressed as Eq. (8):
(5)
CO2 hydrate concentration experiment
Fig. 2 shows the typical CO2 gas uptake curves for a period of 150 min. The general shape of this curve agrees with the gas uptake curve described in detail by reference literatures (Li et al., 2009). As the feed pressure increased from 1.96 to 4.10 MPa, the CO2 gas uptake increased from 0.108 to 0.385 mol, and the needed time to equilibrium state decreased, which was attribute to the reason that more gas was enclosed into hydrate under higher feed pressure. All of these indicate that higher feed pressure is benefit to more hydrate formation and higher hydrate rate.
where a is the interfacial area, K∗ is the overall kinetic constant, f and e are chemical potentials of the guest molecule in the gas phase and in the hydrate phase, respectively, kf is the crystal growth constant, kL is the mass transfer coefficient in the liquid phase. Under the conditions of this study, 1/kL could be eliminated by a vigorous stirring (500 rpm) in the reactor (1/kf 1/kL ). So the hydrate rate can be expressed by Eqs. (6) and (7): rf =
rf =
dn −
dt
n t
= akf (f − e ) = akf RT ln
=
Vg (ff − fe ) RT t
ff fe
(6)
(7)
where ff and fe are the fugacity of the gas phase and the hydrate phase at equilibrium condition, respectively, calculated by SRK equation of state, and fe is assumed to be not strongly affected by dehydration process, Vg is the volume
Fig. 1 – Hydrate phase equilibrium conditions for CO2 + water and CO2 + orange juice systems.
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Fig. 2 – CO2 consumption curve for hydrate formation in the presence of orange juice at 275.8 K from 1.96 MPa to 4.10 MPa.
3.3.
Effect of feed pressure
Firstly, the orange juice concentration experiment was carried out with different feed pressure. In this work, a range of 1.96–4.10 MPa for feed pressure was examined. Fig. 3 shows the result on dehydration ratio as function feed pressure. As shown in Fig. 3, the dehydration ratio calculated according Eq. (3) increased with the feed pressure increasing from 1.96 to 4.10 MPa. The maximum dehydration ratio can reach 57.2% at feed pressure of 4.10 MPa. It is consistent with the trend of CO2 uptake accompanying with feed pressure increasing. These results clearly indicate that CO2 feed pressure plays a key role on the orange concentration by hydrate formation. However, although higher feed pressure was more benefit to concentration efficiency, the higher feed pressure would also need higher compression work.
3.4.
Fig. 4 – Effect of temperature on orange juice dehydration ratio at feed pressure of 3.72 MPa.
Effect of temperature
would need higher refrigeration energy consumption. Comparing with the results of Figs. 3 and 4, the effect of feed pressure on dehydration ratio is more obvious than that of temperature.
3.5.
Effect of orange juice volume
The orange juice concentration process was also carried out with different orange juice volumes at 275.8 K and 3.72 MPa. As shown in Fig. 5, dehydration ratio reached a maximum of 59.5% at the orange juice volume of 60 mL. And with the increase orange juice volume, the mass of removed water accordingly increases. Therefore, on the basis of the above results obtained, the optimum orange juice volume is 80 mL.
3.6.
Effect of stirring speed
The effect of hydrate formation temperature on dehydration ratio was also studied. Fig. 4 shows dehydration ratio as a function of temperature at the feed pressure of 3.72 MPa. It can be seen that dehydration ratio varied from 41.9% to 45.8% in the temperature range of 274.8–279.8 K. The dehydration ratio reached maximum with the lower temperature, which may be attributed to the fact that lower temperature is beneficial to hydrate formation. However, the lower temperature also
The effect of stirring speed on dehydration ratio is given in Fig. 6. It can be seen that the dehydration ratios were about 43% with stirring speed from 400 to 800 rpm at 275.8 K and 3.72 MPa. The result clearly indicated that stirring speed almost has no effect on dehydration ratio. Though the stirring speed is different, the driving force of hydrate formation which is the pressure and temperature differential to equilibrium state is the same.
Fig. 3 – Effect of feed pressure on orange juice dehydration ratio at 275.8 K.
Fig. 5 – Effect of orange juice volume on orange juice dehydration ratio at 275.8 K and 3.72 MPa.
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5
Acknowledgments This research was funded by the National Natural Science Foundation of China (No. 21106085) and Supported by Program for Liaoning Excellent Talents in University (No. LJQ2014042).
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.cherd.2014.07.020.
Fig. 6 – Effect of stirring speed on orange juice dehydration ratio at 275.8 K and 3.72 MPa.
Table 2 – Results for the hydrate formation rate constant. Pressure (MPa)
akf ( × 10–8 mol2 /(s J))
1.96 2.70 3.20 3.72 4.10
3.7.
0.67 0.97 1.34 1.62 1.91
Hydrate formation rate constant
As shown in Table 2, the hydrate formation rate constants calculated using Eq. (8) were 0.67 × 10−8 mol2 /(s J), 0.97 × 10−8 mol2 /(s J), 1.34 × 10−8 mol2 /(s J), −8 2 −8 1.62 × 10 mol /(s J) and 1.91 × 10 mol2 /(s J) with the feed pressure of 1.96 MPa, 2.70 MPa, 3.20 MPa, 3.72 and 4.10 MPa, respectively. The results showed that the hydrate formation constants were in the same order magnitude as the results of CH4 hydrate (30), which were in the presence of different carbon length surfactants. Additionally, the result revealed the rate constant increased with the increase of the feed pressure. It can be explained by the fact that higher driving force was got at higher feed pressure which was consistent with two-film model for hydrate formation process (Englezos et al., 1987; Daimaru et al., 2007).
4.
Conclusion
1) The hydrate phase equilibrium results show that comparing to pure water, the CO2 hydrate formation condition slight shifts to higher pressure and lower temperature in presence of orange juice in which water cut was about 87.7%. 2) The dehydration ratio increased with increasing the feed pressure from 1.96 to 4.10 MPa; the maximum dehydration ratio of 57.2% was reached at feed pressure of 4.10 MPa; dehydration ratio increased from 41.9% to 45.8% in the temperature range of 274.8–279.8 K; the optimum orange juice volume is 80 mL; the stirring speed nearly has no effect on dehydration ratio. 3) The CO2 hydrate formation rate constants increased with the increasing feed pressure ranging from 1.96 to 4.10 MPa. The CO2 hydrate formation constants in this work were in the same order magnitude as the results of CH4 hydrate in the presence of surfactants.
References Aider, M., de Halleux, D., 2008. Production of concentrated cherry and apricot juices by cryoconcentration technology. LWT-Food Sci. Technol. 41, 1768–1775. Andersen, T.B., Thomsen, K., 2009. Separation of water through gas hydrate formation. Int. Sugar J. 111, 632–636. ˘ ˘ Aydogan, Ö., Bayraktar, E., Parlaktuna, M., Mehmetoglu, T., ˘ Mehmetoglu, Ü., 2007. Production of l-aspartic acid by biotransformation and recovery using reverse micelle and gas hydrate methods. Biocatal. Biotransform. 25, 365–372. ˘ Bayraktar, E., AKocapic¸ak, Ö., Mehmetoglu, Ü., Parlaktuna, M., ˘ Mehmetoglu, T., 2008. Recovery of amino acids from reverse micellar solution by gas hydrate. Chem. Eng. Res. Des. 86, 209–213. Cassano, A., Conidi, C., Drioli, E., 2011. Clarification and concentration of pomegranate juice (Punica granatum L.) using membrane processes. J. Food Eng. 107, 366–373. Chun, B.S., Park, S.Y., Kang, K.Y., 2005. Extraction of lysozyme using reverse micelles and pressurized carbon dioxide. Sep. Sci. Technol. 40, 2497–2508. Daimaru, T., Yamasaki, A., Yanagisawa, Y., 2007. Effect of surfactant carbon chain length on hydrate formation kinetics. J. Pet. Sci. Eng. 56, 89–96. Englezos, P., 1993. Clathrate hydrates. Ind. Eng. Chem. Res. 32, 1251–1274. Englezos, P., Kalogerakis, N., Dholabhaiand, P.D., Bishnoi, P.R., 1987. Kinetics of formation of methane and ethane gas hydrates. Chem. Eng. Sci. 42, 2647–2658. Eslamimanesh, A., Mohammadi, A.H., Richon, D., Naidoo, P., Ramjugernath, D., 2012. Application of gas hydrate formation in separation processes, a review of experimental studies. J. Chem. Thermodyn. 46, 62–71. Fan, S., Li, S., Wang, J., Lang, X., Wang, Y., 2009. Efficient capture of CO2 from simulated flue gas by formation of TBAB or TBAF semiclathrate hydrates. Energy Fuels 23, 4202–4208. Gholinezhad, J., Chapoy, A., Tohidi, B., 2011. Separation and capture of carbon dioxide from CO2 /H2 syngas mixture using semi-clathrate hydrates. Chem. Eng. Res. Design 87, 1747–1751. Guignon, B., Aparicio, C., Sanz, P.D., Otero, L., 2012. Orange juice pvT-properties for high pressure processing and modeling purposes. Food Res. Int. 46, 83–91. Huang, C.P., Fennema, O., Powrie, W.D., 1996. Gas hydrates in aqueous-organic systems. II. Concentration by gas hydrate formation. Cryobiology 2, 240–245. Imai, S., Okutani, K., Ohmura, R., Mori, Y.H., 2005. Phase equilibrium for clathrate hydrates formed with difluoromethane + either cyclopentane or tetra-n-butylammonium bromide. J. Chem. Eng. Data 50, 1783–1786. Javanmardi, J., Moshfeghian, M., 2003. Energy consumption and economic evaluation of water desalination by hydrate phenomenon. Appl. Therm. Eng. 23, 845–857. Jesus, D.F., Leite, M.F., Silva, L.F.M., Modesta, R.D., Matta, V.M., Cabral, L.M.C., 2007. Orange (Citrus sinensis) juice concentration by reverse osmosis. J. Food Eng. 81, 287–291.
Please cite this article in press as: Li, S., et al., Concentrating orange juice through CO2 clathrate hydrate technology. Chem. Eng. Res. Des. (2014), http://dx.doi.org/10.1016/j.cherd.2014.07.020
CHERD-1653; No. of Pages 6
6
ARTICLE IN PRESS chemical engineering research and design x x x ( 2 0 1 4 ) xxx–xxx
Jiao, B., Cassano, A., Drioli, E., 2004. Recent advances on membrane processes for the concentration of fruit juices, a review. J. Food Eng. 63, 303–324. Li, S., Fan, S., Wang, J., Lang, X., Liang, D., 2009. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide. J. Nat. Gas Chem. 18, 15–20. Li, S., Fan, S., Wang, J., Lang, X., Wang, Y., 2010. Semiclathrate hydrate phase equilibria for CO2 in the presence of tetra-n-butyl ammonium halide (bromide, chloride, or fluoride). J. Chem. Eng. Data 55, 3212–3215. Liu, B., Liu, H., Wang, B., Wang, J., Sun, C., Zeng, X., Chen, G., 2014. Hydrogen separation via forming hydrate in W/O emulsion. Fluid Phase Equilib. 362, 252–257. ˘ McKov, V., Sinanoglu, O., 1963. Theory of dissociation pressures of some gas hydrates. J. Chem. Phys. 38, 2946–2956. Ngan, Y.T., Englezos, P., 1996. Concentration of mechanical pulp mill effluents and NaCl solutions through propane hydrate formation. Ind. Eng. Chem. Res. 35, 1894–1990. Nguyen Hong, D., Chauvy, F., Herri, J.M., 2007. CO2 capture by hydrate crystallization - A potential solution for gas emission of steel making industry. Energy Convers. Manage. 48, 1313–1322. Ohmura, R., Takeya, S., Maekawa, T., Uchida, T., 2006. Phase equilibrium for structure-H hydrate formed with krypton and 2,2-dimethylbutane. J. Chem. Eng. Data 51, 161–163. Park, K., Hong, S.Y., Lee, J.W., Kang, K.C., Lee, Y.C., Ha, M., Lee, J.D., 2011. A new apparatus for seawater desalination by gas hydrate process and removal. Desalination 274, 91–96.
Purwanto, Y.A., Oshita, S., Seo, Y., Kawagoe, Y., 2011. Concentration of liquid foods by the use of gas hydrate. J. Food Eng. 47, 133–138. Sloan, E.D., Koh, C.A., 2008. Clathrate Hydrates of Natural Gases, third ed. CRC Press, New York. Sun, Q., Guo, X., Liu, A., Liu, B., Huo, Y., Chen, G., 2011. Experimental study on the separation of CH4 and N2 via hydrate formation in TBAB solution. Ind. Eng. Chem. Res. 50, 2284–2288. Tajim, H., Oota, Y., Yamagiwa, K., 2014. Improving the gas recovery and separation efficiency of a hydrate-based gas separation. Chem. Eng. Res. Design, http://dx.doi.org/10.1016/j.cherd.2014.02.008. Tang, J., Zeng, D., Wang, C., Chen, Y., He, L., Cai, N., 2013. Study on the influence of SDS and THF on hydrate-based gas separation performance. Chem. Eng. Res. Design 91, 1777–1782. Tohidi, B., Burgass, R.W., Danesh, A., Østergaard, K.K., Todd, A.C., 2000. Improving the accuracy of gas hydrate dissociation point measurements. Ann. N. Y. Acad. Sci. 912, 924–931. Uchida, T., Takagi, A., Kawabata, J., Mae, S., Hondoh, T., 1995. Raman spectroscopic analyses of the growth process of CO2 hydrates. Energy Convers. Manage. 36, 547–550. Wang, Y., Lang, X., Fan, S., 2013. Hydrate capture CO2 from shifted synthesis gas, flue gas. J. Energy Chem. 22, 39–47. Zhong, D., Englezos, P., 2012. Methane separation from coal mine methane gas by tetra-n-butyl ammonium bromide semiclathrate hydrate formation. Energy Fuels 26, 2098–2106.
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