选择性催化还原(SCR)脱硝是烟气中氮氧化物(NOx)脱除的最有效方法之一,现有SCR系统采用填充床反应器工艺,且催化剂价格较贵。本文以Fe2O3铁基催化剂为床料,以氨为脱硝剂,采用磁流化床进行选择.陛催化还原脱除氮氧化物实验研究,并对反应前后的床料进行EDAX元素分析和XRD分析。实验结果表明:γ-Fe2O3对加氨SCR脱硝有较强的活性,但随着温度的升高,由于γ-Fe2O3对氨的氧化也表现出较强活性,因而在250℃后,γ-Fe2O3催化剂的脱硝效率会降低;另一方面,磁流化床的良好气固接触与传质特性同时改善了,γ-Fe2O3催化剂的上述两个催化活性作用,使其在250℃达到95%的最佳脱硝效率。
Selective catalytic reduction (SCR) of De-NOx is one of the most effective methods for NOx removal from flue gas. The technique of packed bed reactor is applied for most SCR systems now, and catalysts in SCR are much expensive. Experimental studies were done about selective catalytic reduction of NO from flue gas with ammonia on iron-based catalysts (Fe2O3) with magnetically fluidized bed in this paper. X-ray diffraction spectroscopy (XRD) and elemental analysis of EDAX were used to identify and characterize the iron-based catalysts. Results show that γ-Fe2O3 is high active in SCR, but it is also active in ammonia oxidation by O2 at high temperature. Therefore, a optimal NOx conversion, which is 90%, is obtained at 250℃ on γ-Fe2O3 catalyst with a fluidized bed. Furthermore, the NOx conversion increases to 95% on γ-Fe2O3 catalyst at 250℃ with magnetically fluidization technique because of its good characteristics of gas-solid mass transfer on solid particle surface.