化工进展

• 资源与环境化工 • 上一篇    下一篇

造纸白泥的分解和碳酸盐化特性

何兰兰,于敦喜,曾宪鹏,吕为智,吴建群,徐明厚   

  1. 华中科技大学煤燃烧国家重点实验室,湖北 武汉 430074
  • 出版日期:2014-11-05 发布日期:2014-11-01

Investigation on calcination and carbonation performance of papermaking lime mud

HE Lanlan,YU Dunxi,ZENG Xianpeng,Lü Weizhi,WU Jianqun,XU Minghou   

  1. State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,Hubei,China
  • Online:2014-11-05 Published:2014-11-01

摘要: 造纸白泥作为一种碱性工业废弃物占据了大量的土地资源,其资源化利用是一个有待解决的问题。白泥用于工业烟气中CO2的回收是一种有效的资源化利用方式,然而其中还存在一些机理问题有待研究。本文利用热重分析(TGA)技术对造纸白泥和天然石灰石的煅烧分解特性和碳酸盐化特性进行了对比研究。结果表明,在相同煅烧条件下,白泥的分解速率较石灰石快得多,因此完全煅烧所需时间更短。经过相同的煅烧过程后(850℃,纯N2,15min),白泥煅烧产物的碳酸盐化转化率低于石灰石煅烧产物,可能原因在于白泥煅烧产物较石灰石煅烧产物具有更低的比表面积。碳酸盐化温度(600~700℃)对白泥和石灰石煅烧产物碳酸盐化的影响规律相似,升高温度对快速碳酸盐化阶段的反应速率没有明显影响,但是延长了快速反应阶段的持续时间,提高了碳酸盐化转化率。

关键词: 白泥, 二氧化碳捕集, 吸附剂, 废物处理, 分解特性, 碳酸盐化特性

Abstract: Papermaking lime mud is an alkaline industrial waste,taking large land resources in landfill. The use of lime mud to capture CO2 from the industry flue gas is one of the effective ways to solve the problems. However,some fundamental problems still need to be investigated. This paper compared the calcination of lime mud and limestone,and investigated the carbonation of the calcined products in a TGA reactor. The results showed a higher decomposition rate for lime mud than for limestone,leading to a shorter time for complete calcination. After the same calcination process (850℃,N2,15min),CaO derived from lime mud showed a lower carbonation conversion ratio than limestone. This was likely because of the lower specific surface area of CaO derived from lime mud. The influence of temperature on the carbonation performance of the calcinates derived from lime mud and limestone was similar. Increasing temperature in the range of 600—700℃ did not have insignificant effects on the carbonation rate in the fast chemical reaction-controlled carbonation stage. However,it lengthened the fast carbonation stage and resulted in a higher ultimate carbonation conversion ratio.

Key words: lime mud, CO2 capture, sorbent, waste treatment, decomposition properties, carbonation properties