| This paper studies on the anticorrosion capacity with different membrane with pigment extract of tomato skin and grape skin and chooses appropriate membrane for pigment extract purify and concentrate. The optimal membrane module was chosen according to water flux and retention rate of pigment on membrane with different pore size. Then the effect of operating pressure, operating temperature and flow rate to membrane flux were studied and the best concentration multiple of pigment extract was chosen. In addition, the skills of membrane module cleaning were improved according to the simple factor and orthogonal experiment.Comparing the causticity toleration of RC, PVDF, PTFE, PES, the results show that: the best membrane of causticity toleration for acetoacetate and alcohol was RC, the other three were worse. The membrane with max porosity was RC.The study of water flux, solvent flux, retention rate of macromolecule substance and pigment shows that the RC membranes with MWCO 30kDa, 500Da were more suitable for purification and concentration on pigment extract of tomato skin. And the RC membrane with MWCO 1kDa and PTFE membrane with MWCO 300Da were more suitable for purification and concentration on pigment extract of grape skin.After analyzing the influence of critical process technology on membrane flux, it shows that the best technology condition on purification of tomato skin pigment extract was operating pressure 0.10MPa, operating temperature 35℃, and flow rate of dosage liquor 53.50m/s; the best technology condition for concentration was operating pressure 0.60MPa, operating temperature 40℃, and flow rate of dosage liquor 53.50m/s, and in this condition, the best result of concentration was 30 times. And the best technology condition on purification of grape skin pigment extract was operating pressure 0.15MPa, operating temperature 25℃, and flow rate of dosage liquor 71.34m/s; the best technology condition for concentration was operating pressure 0.80MPa, operating temperature 50℃, and flow rate of dosage liquor 71.34m/s, in this condition, the best result of concentration was 25 times.Based on single factor experiment and orthogonal experiment of cleaning condition, the results showed that the best cleaning condition was 1%NaOH+0.1%NaClO, cleaning for 30min, cleaning temperature 40℃, and the recovery rate of membrane flux was 93.28%. For the concentration of tomato skin pigment extract, the best cleaning technology was: first, the equipment was washed using distilled water, then the recombination chemical abluent was used below 40℃for 30min; finally, membrane was cleaned by acetoacetate and distilled water for 10min. Under this condition, the recovery rate of membrane flux reached 98%.The decreasing degree in purification of grape skin pigment extract was lower than purification of tomato skin pigment extract, so the membrane cleaning condition was chosen in purification of tomato skin pigment extract, and the recovery rate of membrane flux was higher than 95%. The cleaning skills of concentration of grape skin pigment extract was: wash the equipment with distilled water for 10mins, then use the recombination chemical abluent below 40℃for 30mins, finally use the distilled water to wash for 30min. The recovery rate of membrane flux was higher than 96%.The results was showed through taking the grape skin pigment extract as an example and according to compare the concentration multiple, energy expenditure between NF concentration and vacuum rotary evaporation: in the same time, the concentration multiple of NF concentration is higher than vacuum rotary evaporations, and the change of pigment content and aberration is unobvious. Besides, the energy expenditure of NF concentration is obviously lower than vacuum rotary evaporation which shows that the project has a good economic benefit.
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