A new energy-saving process of heat pump distillation for desulfurization solvent in renewable flue gas desulfurization

Abstract

The invention provides a novel heat pump distillation energy saving process for a desulfurization solvent in regenerable flue gas desulfurization. The novel heat pump distillation energy-saving process comprises the following steps that A, SO2 is separated from a pregnant solution of an SO2-containing desulfuration solvent at a desulfuration section in a distillation tower through distillation, and a barren liquor at the bottom of the distillation tower is sent to a flash tower, and is flashed in the flash tower; B, flashing steam generated by the flashing is sent to a compressor, and is compressed by using a compressor to act; and C, steam output from the compressor is sent to the bottom in the distillation tower, and forms raising steam required by the distillation together with vaporized water, the raising steam and the pregnant solution falling from the upper part of the distillation tower reversely flow for performing mass and heat transfer to complete the distillation process, part of flashed barren liquor and the steam discharged from the top of the distillation tower are exchanged with heat, and the barren liquor returns to the flashing tower after the steam heat is recycled, the left flashed barrel liquor and the desulfurization solvent pregnant solution entering the distillation tower are exchanged with the heat, and cooled to 40-55 DEG C through water cooling after the heat of the barren liquor is recycled so as to be sent to a desulfurization section for being recycled. When the distillation is performed by adopting the heat pump distillation process, energy can be saved more than 70 percent in comparison with that of a conventional distillation method.

Description

technical field [0001] The invention relates to the technical field of heat pump distillation, in particular to a new energy-saving technology of heat pump distillation for desulfurization solvent-rich liquid in renewable flue gas desulfurization. Background technique [0002] The chemical industry is a large energy consumer, and distillation is a unit operation with extremely high energy consumption. However, the traditional distillation method has low thermodynamic efficiency and a lot of energy waste. For example, in the document "Application of Kangshifu Renewable Amine Desulfurization Technology" ("Sulfuric Acid Industry", 2007(1):39-45), the separation of SO from the desulfurization absorption liquid by distillation 2 , each ton of desulfurization liquid needs to consume 0.1-0.2t0.6MPa saturated water vapor. [0003] In today's situation of rising energy prices, how to reduce the energy consumption of distillation towers and make full use of low-temperature heat sourc...

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Problems solved by technology

[0005] 1. High investment, complex process flow, high-concentration toxic and harmful media are directly compressed by compressors, the compressors are severely corroded or require high material grades, and insufficient heat recovery;

[0006] 2. The compressed gas contains non-condensable gas, which leads to low heat transfer efficiency of the reboiler, high operating pressure of the reboiler, and easy corrosion;

The overhead gas of this process contains a high concentration of SO 2 , severe corrosion, or high requirements on material grades, complex processes, and high concentrations of SO 2 May cause leakage and cause safety of life and property

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