摘要
研究了间歇式反应器中城市污泥的超临界水氧化反应(SCWO)。实验表明:污泥COD去除率可达到99.98%以上,随反应时间增加、温度升高,污泥COD去除率显著增大;压力对过程无显著的影响;氧化剂过量倍数小于一定程度时,对污泥的去除率影响显著,超过此值时则几乎没有影响。应用SCWO能快速实现污泥的减量减容和无害化处理,脱水污泥完全氧化后的残余固体质量仅为脱水污泥的8%;在450℃,经过95s的反应时间后,反应液的化学需氧量即可小于40mg?L?1。此外,藉反应介质焓值的变化探索了污泥SCWO的反应热,获得了反应过程中能量平衡时,污泥的最大含水率和最小有机物质量含量的方程。结果表明:污泥中有机物完全氧化释放的反应热为21319.15kJ?kg?1,在400℃、26MPa条件下,当污泥中有机物质量含量超过3.0%时,SCWO反应即能实现能量的平衡??自热。
The experiments of supercritical water oxidation（SCWO） of municipal sludge were conducted in a batch reactor. The experimental results show that the sludge COD reduction can be over 99.98%, and the COD reduction increases with increasing reaction time and temperature, whereas scarcely changes with pressure. As the excess oxidant ratio is higher than certain value, the effect of the oxidant ratio can be neglected. Applying SCWO can rapidly reduce the sludge volume and make it becomes harmless. After 95s SCWO treatment at 450℃, the mass fraction of remainder solid is about 8% of the dehydrated sludge and the COD of reaction liquid is less than 40mg·L^-1. Based on the enthalpy changes of the reaction mediums, the reaction heat was studied. The calculating equations determing the maximal water ratio and the minimal mass fraction of organic matters in the sludge for self-sustaining the energy balance of the SCWO process were derived. The results indicate that the reaction heat is 21319.15 kJ·kg^-1 when the organics are completely oxidized, and under 400℃ and 26 MPa, the self-sustaiming energy balance of the SCWO reaction can be realized as the mass fraction of organics in municipal sludge is over 3.0%.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2006年第3期379-384,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家重点基础研究发展计划(2003CB214502)
