不同热转化气氛下纤维素焦中有机钾的迁移特性  

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

作　　者：赵海波 徐文婷 宋蔷[2] ZHAO Haibo;XU Wenting;SONG Qiang(Enterprise Bureau of China Development Bank,Beijing 100084,China;Key laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,Beijing 100084,China)

机构地区：[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

出　　处：《化工进展》2021年第8期4631-4637,共7页Chemical Industry and Engineering Progress

基　　金：国家重点基础研究发展计划(2013CB228500);国家自然科学基金(51076072)。

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O_(2)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。O_(2)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K_(2)CO_(3),然后在900℃以上发生明显的气相释放。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 K_(2)CO_(3),and then was released to the gas phase at temperatures above 900℃.

关 键 词：生物质 有机钾 纤维素焦 反应气氛 迁移 

分 类 号：TK6[动力工程及工程热物理—生物能]