A film condensation method for gas dehumidification

Abstract

The invention relates to a membrane condensation method for gas dehumidification. The membrane condensation method comprises the following steps: the water vapor in the wet gas is condensed and transferred through the membrane, and the driving solution on the liquid side of the membrane is condensed by the driving force of the osmotic pressure. absorption, thereby enhancing the delivery process. Under the driving force of the osmotic pressure of the driving solution, the efficient transfer of condensed water can be realized, thereby realizing the efficient dehumidification of gas. The film condensation method of the invention can efficiently recover water vapor in the wet gas, and the water recovery rate can reach up to 85% and the heat recovery rate can reach up to 90% according to the difference in gas humidity. Taking the flue gas of a power plant as an example, the invention can efficiently dehumidify the flue gas, thereby realizing water recovery, avoiding reheating and reducing pipeline corrosion, achieving the purpose of energy saving and emission reduction, being environmentally friendly, and improving the economic benefits of the enterprise .

Description

technical field [0001] The invention belongs to the field of separation, and relates to a method for gas-liquid separation, in particular to a film 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 MembraneCondenser Technology in ACS Sustainable Chemistry&Engineergin (2018), 6(5):6425-6433, which pointed out that if the flue containing saturated water vapor can be If the moisture in the gas is recovered by more than 20%, the self-sufficiency of water for the boiler of the power plant can be achieved. In an article published by Peng Yueyu entitled "Research on Water Recovery and Utilization in Coal-fired Boiler Flue Gas", it was pointed out that, taking a 600MW coal-fired boiler unit as an example, if th...

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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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