The present application belongs to the field of
molecular sieve membrane repair, and particularly relates to a method for repairing a
molecular sieve membrane. The method uses NO2 and SO2 to repair the
molecular sieve membrane. NO2 molecules are prone to dimerization to form N2O4 under certain conditions (low temperature or
high pressure), and N2O4 can react with SO2 to form a complex ONONO-SO3, which can form strong affinity with the hydroxyl group exposed at the defect site of the molecular
sieve membrane, thereby plugging the molecular
sieve membrane channel and repairing the molecular
sieve membrane. For small-pore molecular sieve membranes such as six-membered ring or eight-membered ring, N2O4 has a
kinetic diameter greater than the
pore diameter of the molecular sieve membrane, so it cannot enter the molecular sieve
membrane channel and cause channel plugging. For ten-membered ring or twelve-membered ring molecular sieve membranes with larger pore diameters, the adsorption of the ONONO-SO3 complex is not strong due to the larger
pore diameter of the molecular sieve membrane, and selective heating
desorption can be selected, so the channel will not be permanently plugged.