The invention relates to a method for removing
residual oxygen in a product flow of
ethylene preparation by ethane catalytic oxidative
dehydrogenation, wherein the method comprises the following steps: (1) feeding mixed
raw material gas into an oxidative
dehydrogenation reactor for reaction, carrying out
waste heat recovery and cooling on the obtained crude
product gas, and then feeding the crudeproduct gas into a gas-liquid separation tank for gas-liquid separation; (2) cooling a
gas phase at the top in the gas-liquid separation tank, feeding the cooled
gas phase into an absorption
tower, and obtaining deacidified gas from the top of the absorption
tower under the action of a
tower top absorbent; and (3) feeding the obtained deacidified gas into a
deaerator, and deoxidizing to obtain a deoxidized crude product. Compared with the prior art, the treatment capacity of the
deaerator can be effectively reduced, the equipment investment is reduced, and meanwhile, the improvement of the deaeration reaction depth is facilitated. Besides, part of process condensate is injected into the
mixed feed gas flow, and the reaction
waste heat is gasified and recycled, so that the
reaction temperature rise can be effectively controlled, and more reaction
waste heat can be recycled.