络合铁与PDS在HPF脱硫装置上的差异性研究

临涣公司一期化产HPF脱硫装置设有两套并联运行的脱硫系统,其脱硫工艺分别采用络合铁与PDS两种技术,结合脱硫原理,从工艺控制和工业运行效果等方面分析了两种脱硫技术的差异性。结果表明:两者最本质的区别在于络合铁脱硫技术可从源头上抑制S₂O₃^2-和SCN^-副盐的产生,而PDS技术会产生两盐;相比PDS脱硫,络合铁脱硫对催化剂浓度、脱硫温度、再生空气量等工艺控制的要求更高;络合铁脱硫可将硫化氢质量浓度控制在50 mg/m³以下,其脱硫效果明显优于PDS脱硫的150 mg/m³~300 mg/m³;在不外排脱硫液的情况下,络合铁脱硫可使副盐基本不增长,而PDS脱硫必须外排脱硫液去提盐工段提盐。

Study on difference of chelated iron and PDS in HPF desulfurization unit

A comparative study was carried out on two parallel HPF desulfurization systems in PhaseⅠHPF desulfurization unit of Linhuan Coking Co.,Ltd.,using chelated iron and PDS technologies respectively.In combination with the technical principles,the differences between the two desulfurization technologies were analyzed from the aspects of process control and industrial operation effect.The results showed that the most essential difference between the two processes was that chelated iron desulfurization technology had the advantage of suppressing secondary salt of S2O32-and SCN-from the source,while PDS would inevitably produce the secondary salts.Compared with the PDS desulfurization,chelated iron desulfurization had higher requirements for process control such as catalyst concentration,desulfurization temperature and regenerated air volume.Chelated iron desulfurization could control the mass concentration of hydrogen sulfide below 50 mg/m3,and its desulfurization effect was significantly better than that of PDS desulfurization of 150 mg/m3-300 mg/m3.Under the condition that the desulfurization solution was not discharged,chelated iron desulfurization could basically prevent the increase of the secondary salts,while PDS desulfurization must discharge the desulfurization solution to the salt extraction section.