Study On Purification Performance And Mechanism Of Low Concentration SO₂ In Electronic Cleaning Workshop

There are many studies on thousands of ppm concentration in industrial desulfurization field,but there is no study on low concentration sulfur dioxide(ppb)purification in electronic industrial cleanrooms.This topic mainly studies the purification performance and mechanism of low concentration sulfur dioxide in electronic industry clean workshop.According to ASHRAE 145.1 and iso-10121-1,a test experiment system was built.Five typical purification materials were selected to test their purification performance under different conditions of low concentration and analyze the relationship between adsorption performance and pore structure.Langmuir,Freundlich,Dubinin-Radushkevich and other commonly used adsorption isotherm models were fitted to analyze their applicability at low concentration and to predict the difference of actual concentration saturation adsorption.FTIR,XPS and other characterization techniques were used to conduct qualitative and relative quantitative analysis of the adsorbed products,and the adsorption mechanism was explored in combination with the chemical reaction process and chemical reaction rate of sulfur dioxide.At the same time,the effects of humidity(23±3 ℃,0-75 %RH)and wind speed(0.35-0.75 m/s)on adsorption performance were studiedThe following findings were found in this study: 1)adsorption performance at low concentration is highly correlated with microporous structure,and different modification methods lead to great differences in adsorption performance of different purification materials at low concentration;2)low concentrations Dubinin-Radushkevich adsorption isotherm model fitting effect is poorer,this is because its derivation and assumptions based on physical adsorption,while in the low concentration adsorption and chemical adsorption is the main influence factors of affecting adsorption performance,Langmuir adsorption isothermal model and the commonly used empirical formula Freundlich fitting effect is good,three kinds of adsorption model predicts the electronics industry clean room actual low concentrations of saturated adsorption quantity has significant difference;3)chemical action plays a leading role in low concentration adsorption;4)the purification performance of sulfur dioxide is significantly affected by humidity and wind speed at room temperature,among which the influence of humidity is relatively complex.The high humidity environment is conducive to adsorption,while the influence of adsorption performance in low humidity environment is not significant,which may be due to the coordinated influence of water molecules competing with sulfur dioxide molecules for adsorption and water molecules participating in the reaction.The above conclusions provide reference and guidance for understanding the performance of chemical filters for removing acidic gaseous molecular pollutants in electronic industry clean workshop and practical application,and provide certain data and theoretical basis for the research and development of material modification.