2. Theory of MACC
A schematic diagram of the ideal MACC process is shown in Figure 1. The crystallization solution and the cooling liquid flow along the shell side and tube side of the membrane module, respectively. When the coolant feed into the hollow fiber membrane module, it can decrease the temperature of the crystallization solution to the metastable zone effectively due to the outstanding heat exchange property of the membrane module. The operation pressure difference and temperature difference on the two sides of the membrane are both small, thus, there is only heat transfer on the membrane surface, and the transmembrane mass transfer can be ignored. The induced nucleus on the supercooling membrane surface then migrates from the membrane surface to the bulk crystallization solution under the proper flow conditions. To describe this complicated dynamic process, the relevant model should be introduced.