镁法烟气脱硫副产物热解回收的研究 -

镁法烟气脱硫工艺是利用MgO浆液吸收烟气中的SO2,脱硫副产物经过热解还原为MgO后,可再次制浆从而实现吸收剂的循环利用。对某火电厂的脱硫副产物进行分析,发现每克干渣中含MgSO3 0.723 g(折算值),具有良好的回收利用价值。分别考察了热解温度、恒温时间等热解条件对热解产物的影响,发现在热解温度750℃、恒温时间2 h时,MgO回收率可达到59.8%。热解温度低于750℃时,脱硫副产物单质硫析出占理论硫比例为6.0%;当热解温度达到900℃时,单质硫析出达到了24.0%。故在热解脱硫副产物时,应控制热解温度以减少单质硫的析出。 Magnesium oxide slurry is used for sulfur dioxide removal in regenerative magnesia scrubbing flue gas desulfurization(FGD) system.Magnesia is regenerated from desulfurization by-products through pyrolysis process and is applied in the system as recycling agent.A thermal power plant desulfurization by-products were analyzed,the plant desulfurization by-product contents 0.842 g MgSO3 per-gram of dry residue,has great recovery value.Investigated the pyrolysis conditions of the by-product such as pyrolysis temperature and heating time.Under the condition that pyrolysis temperature is 750 ℃ and heating time is 2 h,the recovery rate of MgO can reach 59.8%.Confirmed that the exhalation rate of sulfur occupied 6.0% of the theoretical value when pyrolysis temperature is below 750 ℃ and reached 24.0% when pyrolysis temperature is 900 ℃.Pyrolysis temperature should be controlled to reduce the exhalation of sulfur during the pyrolysis process of the by-products