A method of combining low-temperature waste heat utilization of flue gas with treatment of saline wastewater

Abstract

The invention relates to the field of petrochemical engineering and provides a method of combination of flue gas low-temperature waste heat utilization and salt-containing waste water treatment. The method is characterized by including the steps of: 1) completing an absorbent solution circulation; 2) completing a refrigerant circulation; 3) completing a high-temperature flue gas heat exchange circulation; 4) completing a low-temperature flue gas heat exchange circulation; and 5) closely combining absorption heat exchange with low-temperature multiple-effect evaporation, so that the two processes of the absorption heat exchange and the low-temperature multiple-effect evaporation can be completed. By means of integration of a condenser in absorption heat exchange and a first-effect evaporator in the low-temperature multiple-effect evaporation, the low-temperature waste heat utilization and the salt-containing waste water treatment are combined, so that a heat medium water step is canceled. The method is reduced in heat exchange temperature difference and system loss, is increased in device economy and achieves the double objects of saving energy and reducing emission in a manner of treating wastes with wastes.

Description

technical field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for treating high-concentration saline waste water of refining and chemical enterprises. Background technique

[0002] Petrochemical enterprises will produce a large amount of wastewater, mainly including oily wastewater, sulfur-containing wastewater, saline wastewater and high-concentration ammonia-nitrogen wastewater. Among them, high-salinity wastewater is one of the difficult wastewaters. High-salinity organic wastewater refers to wastewater containing organic matter and at least 3.5% (mass fraction) total dissolved solids. This saline wastewater often contains high concentrations of soluble inorganic substances. Salt such as Ca 2+ 、Na + , Cl + The salt content is more than 3 times that of sea water.

[0003] The main sources of saline wastewater are: 1) Atmospheric and vacuum electric desalination wastewater; 2) High-salt waste lye and phenol-ac...

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