Nanofiltration Theory Research On Aquous Solution Of Polyols

The paper choose the aquous solution of three kinds of lowmolecular weight neuter substances(sorbitol, maltitol and anotherpolyols) to experiment, the concentration is from 0.05% to 11.8%.Transfer idiosyncrasy of the three polyols in nanofiltration membraneL, K, and E has been studied, and a new nanofiltration theory modelhas been formed, based on the PORE MODEL and theSOLUTION-DIFFUSION MODEL. It can be used to forcastpermeation in nanofiltration membrane of polyols.Firstly, we gain a similarity of Solution-diffusion-imperfectionmodel, under some supposing, and based on former theory models.And then, we confirm the factors in the model, calculate themass-transfer coefficient k in the boundary layer of membrane andthe concentration C m in membrane face, and fit the solute diffusioncoefficient B where this is no pore and the membrane parameters ,andLpPs σ . Verification is carried out partly by comparing with theothers' results and experiment data, And a new nanofiltrationmass-transfer model applied with polyols is formed at last. The newmodel has two merits: ① the application concentration is expandedfrom 1% to 10%;② convection transfer in the pore and diffusiontransfer where there is no pore have both been considered in the newmodel.Verification about rationality of the new model is carried outpartly by comparing with the others' results and experiment data.Prediction on L and E membrane is carried out. The relationbetween the new model and the applied conditions(pressure,concentration and circular flux) has been deduced. This could leadthe produce practice.