磷钼杂多化合物脱除H2S回收硫磺反应机理研究

综合运用离子选择电极分析、微分量热分析与能谱分析等手段对磷钼杂多酸钠盐与硫化氢的反应机理进行了研究。发现：1）磷钼酸钠体系在脱硫过程中具有稳定的化学性能，硫产物中基本不含Mo,V的物相；2）脱硫过程中，复配体系磷钼酸钠与偏钒酸钠独立作用，两者之间不存在协同效应；3）磷钼酸钠吸收H2S过程的化学反应式为：H2S Na3PMo( Ⅵ）12O40→S↓＋Na3H2PMo(Ⅵ)10Mo(Ⅴ)2O40。即在磷钼酸钠分子中有2个Mo(Ⅵ)被还原成Mo(Ⅴ)，因此，相同摩尔浓度下，磷钼酸钠的饱和硫容量是螯合铁的两倍。

ON THE REACTION MECHANISM OF HYDROGEN SULFIDE REMOVAL AND SULFUR RECOVERY WITH SODIUM PHOSPHOMOLYBDATE

At present,no proof was given on the exact number of electron transferred during the redox reaction between sodium phosphomolybdate and reductants including hydrogen sulfide.With the aid of ISE(ion-selective electrode),DSC(differential scanning calorimetry)and ES(energy spectrum),the mechanism of desulfurization reaction was studied and it was found：　　1)The reaction products contain little deposition compounds of molybdenum and vanadium，indicating that sodium phosphomolybdate is still much stable in its chemical property after many times of absorption-regeneration cycles,the agent loss is much lower than that of the chelateiron method.　　2)In the blending agent system,sodium phosphomolybdate and sodium metavanadate act independently,no synergistic effect existed during the process of hydrogen sulfide removal.　　3)The chemical equation of sodium phosphomolybdate and H2S was proposed to be：H2S+Na3PMo(Ⅵ)12O40S↓+Na3H2PMo(Ⅵ)10Mo(Ⅴ)2O40i.e.,there are two Mo(Ⅵ)atoms reduced to Mo(Ⅴ).Therefore,the theoretical saturation sulfur loading capacity of sodium phosphomolybdate is twice that of chelate iron with the same molar concentration.