María-José Corbatón-Báguena

24 Aug 2012

María-José Corbatón-Báguena holds a Bachelor’s degree in Chemical Engineering and a Master’s degree in Environmental and Industrial Safety from the Universidad Politécnica de Valencia, obtaining the “Prize awarded to the Student with the Best Academic Record” in Chemical Engineering at the same university in 2011. She is carrying out the PhD studies on “Engineering and Industrial Production” and she is working on a research project directed by Dr. Silvia Álvarez-Blanco and funded by the Spanish Ministry of Science and Innovation (MICINN), focused on the cleaning of ultrafiltration membranes used in the food industry by means of non conventional techniques. She presented several works in the International Congress on Membrane and Membrane Processes (ICOM) and the Network Young Membrains 13 (NYM13), which took place in The Netherlands in July, 2011. She also presented works in the Conference and Exhibition of Desalination for the Environment: Clean Water and Energy and in the International Congress of Chemical Engineering, which were celebrated in Barcelona and Seville, 2012, respectively.

PDF of presentation


Abstract


Ultrafiltration membrane cleaning using NaCl solutions: influence of cleaning conditions.

Most of the industrial developments of membrane technologies in the food industry have been originated from the dairy industry, being ultrafiltration (UF) the most widely used process in the world dairy industry when concentration, purification and fractionation of milk and whey is required [1]. In the last years, consolidation of UF in the dairy industry has been due to the fact that this separation process is a non-thermal process and it does not involve phase changes or any addition of chemical agents [2].

However, the major disadvantage of UF is membrane fouling. In the dairy industry, this is mainly due to protein accumulation and deposition on the membrane surface and inside its pores. Membrane fouling is responsible for the increase in the hydraulic resistance of the membrane and the decrease in permeate flux. Therefore, it is necessary to use cleaning processes to restore the initial membrane conditions. Cleaning procedures consume a great amount of water, chemicals, energy and time. Thus, optimization of operating conditions during membrane cleaning is an essential step in UF processes. Response Surface Methodology (RSM) is one of the most often used statistical tools to optimize the operating conditions in UF processes [3, 4].

Experiments were performed in an UF pilot plant using a ceramic monotubular membrane of 15 kDa (TAMI Industries, France). Each run consisted of four steps: fouling, first rinsing, cleaning and second rinsing. An aqueous solution of bovine serum albumin (BSA) with a concentration of 1% (w/w) was used in the fouling step. The fouling conditions were a transmembrane pressure of 2 bar and a crossflow velocity of 2.4 m/s. Cleaning was performed with NaCl solutions at a transmembrane pressure of 1 bar, a crossflow velocity of 4.2 m/s and three different temperatures (25, 37.5 and 50 ºC) and concentrations (0, 2.5 and 5 mM). After the experiments, the membrane was conditioned with a 20 g/L NaOH solution, to restore its initial permeability when necessary.


The hydraulic efficiencies of the first rinsing (HRE) and cleaning (HCE) steps were calculated by means of Eqs. 1 and 2:


The influence of temperature and NaCl concentration on the hydraulic cleaning efficiency (HCE) was studied. When the temperature of the cleaning process increases, HCE increases. This is due to the positive effect of the temperature on the rate of the chemical reaction between the salt and the foulants. Moreover, high temperatures favour the transport of foulant molecules to the bulk solution. However, HCE increases when NaCl concentration increases up to an optimal value, but a further increase of salt concentration has a negative effect on HCE. Optimal values of temperature and concentration were obtained by means of a Response Surface analysis. Temperatures higher than 44 ºC and concentrations of about 3 mM, resulted in HCE values higher than 98 %.


Acknowledgments

This work was supported by the Spanish Ministry of Science and Innovation through the project CTM2010-20186 and by the Polythecnic University of Valencia through its program PAID-06-10.

References

[1] G. Daufin, J.-P. Escudier, H. Carrère, S. Bérot, L. Fillaudeau, M. Decloux, Recent and emerging applications of membrane processes in the food and dairy industry, Trans IChemE 79 (2001) part C, pp. 89-102.

[2] C. Almandoz, C. Pagliero, A. Ochoa, J. Marchese, Corn syrup clarification by microfiltration with ceramic membranes, Journal of Membrane Science 363 (2010) 87-95

[3] M-C. Martí-Calatayud, M-C. Vincent-Vela, S. Álvarez-Blanco, J. Lora-García, E. Bergantiños-Rodríguez, Analysis and optimization of the influence of operating conditions in the ultrafiltration of macromolecules using a response surface methodological approach, Chemical Engineering Journal 156 (2010) 337-346.

[4] E. Alventosa-deLara, S. Barredo-Damas, M.I. Alcaina-Miranda, M.I. Iborra-Clar, Ultrafiltration technology with a ceramic membrane for reactive dye removal: optimization of membrane performance, Journal of Hazardous Materials 209-210 (2010) 492-500.