Membrane condensation method of gas dehumidification

Abstract

The invention relates to a membrane condensation method of gas dehumidification. The membrane condensation method comprises the following steps that water vapor in wet gas is condensed and transferredthrough a membrane, condensed water is absorbed by a driving solution on the liquid side of the membrane through osmotic pressure driving force, and thus the transferring process is enhanced. Under the action of the osmotic pressure driving force of the driving solution, the condensed water can be efficiently transferred, and thus the efficient dehumidification of the gas is achieved. According to the membrane condensation method, the water vapor in the wet gas can be efficiently recovered, according to the different humidity of the gas, the water recovery rate can be up to 85%, and the heatrecovery rate can be up to 90%. Flue gas of a power plant is taken as an example, the flue gas can be efficiently dehumidified, thus the water recovery can be achieved, reheating is avoided, pipelinecorrosion is reduced, the purposes of energy conservation and emission reduction are achieved, environmental protection is achieved, and economic benefits of the enterprise can be improved.

Description

technical field [0001] The invention belongs to the field of separation, and relates to a gas-liquid separation method, in particular to a membrane condensation method for gas dehumidification. Background technique [0002] The flue gas discharged from the wet desulfurization process of coal-fired power plants carries huge latent heat and contains saturated water vapor. Kim J F et al. published an article entitled Harnessing Clean Water from Power Plant Emissions Using Membrane Condenser Technology in ACS Sustainable Chemistry & Engineering (2018), 6(5):6425-6433, which pointed out that if the flue containing saturated water vapor can be If more than 20% of the moisture in the gas is recovered, self-sufficiency in water for power plant boilers can be realized. Peng Yueyu pointed out in an article titled Research on Moisture Recovery and Utilization of Coal-fired Boiler Flue Gas that, taking a 600MW coal-fired boiler unit as an example, if the condensate recovery rate can re...

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Problems solved by technology

[0008] The above method recovers the saturated water vapor in the flue gas by means of membrane separation, but as the recovery proceeds, the temperature difference between the flue gas side and the circulating water side gradually decreases, and the driving force of the condensed water from the flue gas side to the circulating water side If it is lowered, the recovery efficiency of water vapor in the flue gas will decrease, and the heat recovery rate will also decrease; therefore, it is of great significance to propose a membrane separation method that can maintain the water recovery rate for energy saving, emission reduction, and economic benefit improvement.

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