催化裂化装置可再生法烟气脱硫技术若干问题探析

Discussion on several issues of renewable technology of flue gas desulfurization in catalytic cracking unit

干法(活性焦)可再生脱硫技术和湿法(有机胺)可再生脱硫技术,在吸附剂(吸收剂)循环使用、酸性气二氧化硫(SO_(2))回收利用等方面均符合循环经济和绿色发展理念的要求。干法(活性焦)可再生脱硫技术可实现脱硫脱硝一体化协同处理、高盐废水“零排放”和净化烟气达标排放,适用于原料烟气中SO_(2)质量浓度小于或等于2000 mg/m^(3)的场景,回收得到干酸性气SO_(2)的体积分数大于20%(干基),工艺过程产生的废活性焦细粉属于危险废物,将成为该技术推广应用的制约因素,需要妥善处置。湿法(有机胺)可再生脱硫技术可实现烟气中高浓度SO_(2)脱除,需要选择性催化还原(SCR)脱硝技术配合才能实现烟气净化过程,适用于原料烟气中SO_(2)的质量浓度大于2000 mg/m^(3)的场景,且SO_(2)的质量浓度上限(15-20 g/m^(3))范围较宽,回收得到湿酸性气SO_(2)的体积分数大于90%(湿基),减少含胺废水排放数量,提高氧化处理效果,是该技术的绿色发展方向。

The renewable desulfurization technology of dry process(active coke)and wet process(organic amine)meets the requirements of circular economy and green development concept in terms of the recycling of adsorbent(absorbent)and the recycling of acid gas sulfur dioxide(SO_(2))and other aspects.Dry process renewable desulfurization technology can realize integrated desulfurization and denitrification co-processing,“zero discharge”of high-salinity wastewater,and purified flue gas emission standards.It is applicable to the situation that SO_(2) in raw material flue gas is less than or equal to 2000 mg/m^(3).The volume fraction of recovered dry acid gas SO_(2) is greater than 20%(dry basis).The waste process active coke fine powder generated in the process belongs to hazardous waste,which will become a restrictive factor for the popularization and application of this technology and needs to be properly disposed of.The wet renewable desulfurization technology can achieve the removal of high concentration SO_(2) in the flue gas.It requires selective catalytic reduction(SCR)denitration technology to achieve the whole process of flue gas purification.It is suitable for scenarios where SO_(2) in raw flue gas is greater than 2000 mg/m^(3),and the concentration limit(15-20 g/m^(3))is wide,the recovered wet acid gas SO_(2) concentration is greater than 90%(wet base),reducing the discharge of amine-containing wastewater and improving the oxidation treatment effect,which is the green of this technology direction of development.