DEVELOPMENT OF HPA-BASED NEW REGENERABLE LIQUID REDOX ABSORBENT SYSTEM FOR SO₂ REMOVAL FROM GAS STREAMS

抄録

Using HPA (heteropoly acid), namely Na₂HPMo₁₂O₄₀, as absorbent in form of aqueous solution, a promising resolution to SO₂ containing gas purification was developed. In this study, experiments were conducted concerning the additive effect for maximizing the desulfurization efficiency of HPA absorbent system and the performance of absorbent regeneration. As a consequence, all additives including NaCl, H₃PO₄, MnSO₄, CuSO₄, ZnSO₄ and NH₄VO₃ were found to have positive effects on the improvement of the desulfurization efficiency of HPA solution. Among them, the effect of NaCl is the most significant. The following two couples i.e. NaCl vs H₃PO₄ and Zn²⁺ vs Mn²⁺, were found to have interactions. Based on orthogonal experiments, the optimum additive/HPA molar ratio in multi-component absorbent system was gained. The process of HPA regeneration by air stream is strongly influenced by operation temperature, whereby the optimum regeneration temperature was found to be ca. 51°C. The desulfurization efficiency of single HPA shows excellent reproducibility during long time operation of 6 absorption-regeneration cycles. The resultant solution of single HPA after desulfurization can also be effectively regenerated by gas stream containing NO_x, which shows better effect than that by air stream.