基于铁基载氧体的市政污泥气化特性模拟及实验研究

Simulation and Experimental Study on the Gasification Characteristics of Municipal Sludge by the Fe-Based Oxygen Carrier

基于Aspen Plus软件中的模拟及流化床反应器中的部分实验,研究了铁基载氧体在市政污泥化学链气化中对碳转化效率、合成气组分、硫氮污染物排放等特性的影响。结果表明:燃料反应器中氧/碳摩尔比(n(O)/n(C))的增加提高了污泥的碳转化率,但却降低了CO、H 2的浓度,碳转化率趋于平稳时明显减少了羰基硫(COS)和H 2S的排放;燃料反应器中温度的提升利于合成气热值和污泥气化率的提高,降低H 2S排放量的同时增加SO 2的生成;随着水蒸气与污泥质量流量比的增加,H 2的摩尔分数明显上升,在其质量流量比超过12时,变化不再明显;空气反应器中空气与载氧体摩尔流量比(空载比)的增加会使载氧体再生程度提高,但空载比增加到1.3时,开始有大量NO x的生成;空气反应器中反应温度的升高对载氧体的再生影响不大,但会导致热力型NO x的产生。

Based on Aspen Plus simulations and experiments in fluidized bed reactor,the effects of the Fe-based oxygen carrier on carbon conversion efficiency,syngas component and sulfur-nitrogen pollutant emission were studied.The results show that increasing O/C molar ratio in fuel reactor increases the carbon conversion of sludge,but decreases the concentration of CO and H 2.When the carbon conversion tends to be stable,the emission of COS and H 2S is obviously reduced.The increase of fuel reactor temperatures is beneficial to the increase the heat value of syngas and the gasification rate of sludge,which reduces the H 2S and increases the SO 2 generation at the same time.As the mass flow ratio of water vapor to sludge mass increases,the molar fraction of H 2 increases significantly,which reaches the equilibrium when the mass flow ratio exceeds 12.Increasing the air-oxygen carrier molar flow ratio in the air reactor increases the degree of oxygen carrier regeneration.However,but a large number of NO x are generated if the air-oxygen carrier molar flow ratio becomes 1.3.The increase of reaction temperatures shows little effects on the regeneration of the oxygen carrier,while it results in the generation of thermodynamic NO x.