Chemical Industry and Engineering Progress ›› 2021, Vol. 40 ›› Issue (8): 4631-4637.DOI: 10.16085/j.issn.1000-6613.2020-1916

• Resources and environmental engineering • Previous Articles     Next Articles

Migration characteristics of organic potassium during the thermal conversion process of cellulose char under different atmospheres

ZHAO Haibo1(), XU Wenting2, SONG Qiang2()   

  1. 1.Enterprise Bureau of China Development Bank, Beijing 100084, China
    2.Key laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China
  • Received:2020-09-27 Online:2021-08-12 Published:2021-08-05
  • Contact: SONG Qiang

不同热转化气氛下纤维素焦中有机钾的迁移特性

赵海波1(), 徐文婷2, 宋蔷2()   

  1. 1.国家开发银行企业局,北京 100031
    2.清华大学热科学与动力工程教育部重点实验室,北京 100084
  • 通讯作者: 宋蔷
  • 作者简介:赵海波(1991—),男,博士,研究方向为生物质热利用与污染物控制。E-mail:zhaohaibo01@cdb.cn
  • 基金资助:
    国家重点基础研究发展计划(2013CB228500);国家自然科学基金(51076072)

Abstract:

The release of potassium (K) in biomass thermal utilization can cause severe technical problems with deposition, slagging and corrosion on heat transfer surfaces. Char-associated organic K (char-K) is an important occurrence form of K in biomass char. In this study, the migration behavior of char-K during pyrolysis and oxidization of cellulose char was investigated. Under Ar pyrolysis atmosphere, obvious release of char-K can be observed at 800—1000℃. The release rate of char-K increased significantly with temperature. In the end, part of char-K stably remained in the cellulose char. Under reaction atmosphere, only a small amount of K was released at 800℃, and the release ratio of K increased significantly with temperature. The K release ratio first increased slowly and then rapidly with time. After the cellulose char was completely oxidized, there was still obvious K released from ash. Combined with the XRD analysis of ash residues, it was found that with the consumption of cellulose char matrix, char-K was first converted into K2CO3, and then was released to the gas phase at temperatures above 900℃.

Key words: biomass, organic K, cellulose char, reaction atmosphere, migration

摘要:

生物质热转化过程中钾(K)的释放会造成换热面积灰、结渣、腐蚀等技术问题。有机钾是生物质焦中K的重要赋存形式。本文研究了在Ar热解气氛和O2反应气氛下纤维素焦中有机K的迁移行为。Ar热解气氛下,在800~1000℃都有明显的有机K释放,释放速率随温度增加明显增加,但最终都有部分有机K稳定地留在固相中。O2反应气氛下,800℃时纤维素焦中只有少量K发生释放;随着温度的增加,K的释放比例明显增加。在900℃和1000℃ K的释放比例随时间先缓慢增加后快速增加,当纤维素焦完全氧化后,灰分中仍有明显的K释放。结合对灰分的XRD分析发现,随着纤维素焦的消耗,其中稳定存在的有机K主要转化为K2CO3,然后在900℃以上发生明显的气相释放。

关键词: 生物质, 有机钾, 纤维素焦, 反应气氛, 迁移

CLC Number: 

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