垃圾热转化中碱金属迁移转化的热力学平衡分析

Thermodynamic equilibrium analysis on migration and transformation of alkali metals in thermal conversion of municipal solid wastec

垃圾中碱金属会导致其在气化焚烧过程中的团聚、烧结、沉积及腐蚀等一系列问题。试验通过吉布斯自由能最小化热力学平衡法模拟研究了垃圾气化和焚烧过程中碱金属Na和K的迁移和转化规律。考察了反应温度、当量比(或空气过量系数)、垃圾中Cl的含量等主要工艺参数对碱金属迁移和转化的影响。研究结果表明,反应温度对碱金属的分布有很大的影响,温度升高会提高碱金属的挥发性。当量比或空气过量系数对碱金属的分布影响较小。Cl含量对碱金属的分布有很大的影响。当Cl含量小于1.0%时,Cl的增加会导致碱金属挥发性的急剧提高。当Cl含量大于1.0%时,Cl的增加会导致碱金属挥发性的缓慢降低。

The alkali metals of municipal solid waste （MSW） could cause series of problems of ag- glomeration, sinter, deposition and corrosion during gasification and incineration of MSW. The mi-gration and transformation of alkali metals （Na and K） during MSW gasification and incineration through the thermodynamic equilibrium method was studied. The influence of reaction temperature, equivalent ratio （or excess air ration） and C1 content on the migration and transformation of alkali metals were investigated. The results showed that heavy metals were affected distinctly by reaction temperature. The increase of reaction temperature could result in the reduction of alkali metals volatility. The increase of equivalent ratio （or excess air ration） had little impact on the volatility of alkali metals. The distributions of alkali metals were affected significantly by C1 content. While the C1 content was less than 1.0%, the increase of C1 content could led to the increase of alkali metals volatility. While the C1 content was more than 1.0%, the increase of C1 content could lead to the decrease of alkali metals volatility.