基于钴改性的钙基吸附剂污泥富氢气化  

Performance of cobalt modified calcium sorbents for steam gasification of sewage sludge

作　　者：赵正浩 向文国[1] 陈时熠[1] 马士伟[1] 朱珉[1] 华心果 ZHAO Zhenghao;XIANG Wenguo;CHEN Shiyi;MA Shiwei;ZHU Min;HUA Xinguo(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University,Nanjing 210009,Jiangsu,China)

机构地区：[1]东南大学能源热转换及其过程测控教育部重点实验室

出　　处：《化工进展》2019年第10期4747-4754,共8页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51576042)

摘　　要：基于钙基吸附剂的污泥蒸汽气化制取富氢合成气是一种高效环保的污泥处理方式。本文采用溶胶-凝胶法制备了Co改性、Al2O3为载体的钙基吸附剂。借助热重分析仪测定不同钙基吸附剂在多个碳酸化和煅烧循环中的CO2吸附能力和循环稳定性,并在固定床上进行污泥蒸汽气化实验。结果显示:煅烧过程中,以Al2O3为载体的钙基吸附剂中的Al2O3与CaO生成七铝酸十二钙(Ca12Al14O33),并表现出优异的孔隙结构的和CO2吸附能力,其中,Co质量分数为10%的吸附剂在30次循环(700℃碳酸化35min,850℃煅烧5min)中碳酸化率稳定在70%左右;提高气化温度及Co的添加量可促进焦油裂解和甲烷重整反应,显著提高了合成气中H2的浓度和产量及污泥气化的冷煤气效率,有利于富氢气体的制取;在650℃下,相比于纯CaO,添加Co质量分数为15%的吸附剂时,H2产量提高了102%,H2体积分数提高到85%。Production of hydrogen-rich syngas from sludge steam gasification based on calcium-based sorbents is an efficient and environmental friendly sludge treatment method.In this paper,a series of calcium-based sorbents were prepared by sol-gel method,using Al2O3 as support and Co as catalytic active ingredient.The CO2 capture capacity and cyclic stability of calcium-based sorbents in multiple carbonation and decarbonization cycles were measured by thermogravimetric analyzer,and sludge steam gasfication experiments were carried out on a fixed bed reactor.The results show that Al2O3 and CaO in calcium-based sorbents supported with Al2O3 form mayenite(Ca12Al4O33).The calcium-based sorbents have great pore structure and CO2 adsorption capacity.The carbonation conversion of sorbents with 10%Co content was stable at about 70%in 30 cycles.Increase of gasification temperature and the addition of Co in calcium-based sorbents promote tar cracking and methane reforming,and significantly increases H2 yield and syngas concentration and cold gas efficiency of sludge gasification.Compared to pure CaO,H2 yield increases by 102%and H2 concentration reaches 85%in syngas when sorbents with 15%Co content is applied at 650℃.

关 键 词：污泥 制氢 钙循环 改性 钴 

分 类 号：TK6[动力工程及工程热物理—生物能]