湿法脱硫烟气中多形态颗粒物的测量方法及组分特征

为全面测量固定源湿法脱硫烟气中多形态颗粒物的排放浓度及其离子组成特征,提出了一种基于一级冷凝、二级过滤和一级冲击吸收的多形态烟气颗粒物的同步测量方法,外场实测了3种湿法脱硫和除尘工艺的排放水平。现场测试表明：简易湿法除尘脱硫（NaOH法）一体化装置烟气中可过滤颗粒物（FPM）浓度为（36±11）mg/m³,可逃逸颗粒物（EPM）浓度为（33±7）mg/m³;氧化镁法+布袋除尘工艺烟气中FPM浓度为（14±5）mg/m³,EPM浓度为（13±6）mg/m³;石灰石-石膏脱硫+电袋除尘工艺烟气中FPM浓度低,小于3 mg/m³,EPM浓度为（6±1）mg/m³;烟气中EPM是传统滤膜法检测FPM浓度的0.7~5.7倍,EPM的主要存在形态为冷凝液中的可溶解颗粒物（DPM）,颗粒物的组分与脱硫方法密切相关,各形态颗粒物的主要组分是SO₄^2-、SO₃^2-、NO₃^-、NO₂^-、NH₄⁺、Cl^-、Na⁺、Mg²⁺和Ca²⁺等离子。

Characterization of the Inorganic Ionic Composition of Multi-state Particulate Matter in Wet Desulfurized Flue Gas from Stationary Sources by a New Assembled Device

The wet desulfurized flue gas emitted from a stationary source contains four forms of particulate matters. This paper proposed an assembled testing method to measure the multi-state particulate matter in wet flue gas desulfurization (WFGD) emission, which composes a one-stage rapid condensation, two-stage filtering and an impact absorber. Both the concentration and composition of the Filterable Particulate Matter(FPM), Escapable Particulate Matter(EPM)in the WFGD emission were measured and analyzed in field for limestone-gypsum, an alkaline(NaOH) and a MgO desulphurization device, respectively, under their steady running conditions. Experimental data showed that the FPM concentration for the one with combined use of NaOH and wet scrubber was about (36±11)mg/m³, and its EPM concentration was about (33±7)mg/m³; while the FPM concentration for the one with MgO desulphurization device, which all combined with a bag filter, was lower than the former as about (14±5)mg/m³, and their EPM concentration was about (13±6)mg/m³. But the FPM concentration emission from limestone-gypsum device, which combined electrostatic precipitator with a bag filter, was lowest concentration, as less than 3 mg/m³, and their EPM concentration was also the lowest, as about (6±1)mg/m³. It was found that the EPM mainly existed in the form of dissoluble particulates in the condensed fluid, and the concentration was 0.7-5.7 times of the FPM that measured by the traditional method using a filter or filter cylinder. The main chemical components of particulate matter were closely related to the desulfurization methods. And the main components of EPM is SO₄^2-, SO₃^2-,NO₃^-,NO₂^-, NH₄⁺,Cl^-,Na⁺,Mg²⁺and Ca²⁺.