Internal-pressure-type gas-dissolving vacuum membrane distillation concentration method of ethylene glycol solution

The invention discloses an internal-pressure-type gas-dissolving vacuum membrane distillation concentration method of an ethylene glycol solution. The method mainly comprises following steps: (A) pumping an ethylene glycol water solution into a raw water tank; (B) mixing the ethylene glycol water solution in the raw water tank and a gas, such as air, nitrogen and the like, and pumping the mixture into a hollow fiber membrane assembly; (C) vacuumizing a permeation side of a hollow fiber membrane assembly, so that condensable gas is condensed through a condenser at the permeation side to form water while a concentrated ethylene glycol solution is fed back to the raw water tank for circulating concentration. By means of the method, the ethylene glycol solution in a process of preparing ethylene glycol from oxirane through a hydration method can be deeply concentrated and dehydrated through internal-pressure-type gas-dissolving vacuum membrane distillation and then can be purified in a rectification unit to obtain ethylene glycol. Compared with multiple-effect evaporation, the method is less in equipment investment, is high in treatment efficiency, is low in operation temperature and operation pressure and is low in energy consumption.