钙基吸收剂-毕业设计1114

本科毕业论文（设计）

论文（设计）题目：掺杂剂改性钙基吸收剂的碳捕捉特性实

验研究

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2020年6 月1日

本科毕业论文（设计）

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掺杂剂改性钙基吸收剂的碳捕捉特性实验研究

摘要

随着社会工业日新月异般的发展，CO2等温室气体对全球生态环境的影响也愈演愈烈。钙基吸收剂能够很好地捕集CO2，并且在需要时能够释放出高纯度的CO2，因此备受碳捕集研究者们的瞩目。但是，钙基吸收剂的循环特性也受限于诸如CaO高温烧结、吸收剂受到产物CaCO3的包裹等，在多次循环吸收CO2以后其吸收能力会大幅度下降。为此，对钙基吸收剂进行改性显得尤为重要，其中掺杂改性的关注度越来越高。

本文阐述了国内外二氧化碳捕集和钙基改性的现状，并分析了钙基吸收剂循环捕集二氧化碳原理和吸收剂循环碳捕捉性能衰减原因。基于此，笔者以常见的废弃物鸡蛋壳作为前驱体，采用高温固相的方法制备成钙基吸收剂样品，借助热重分析仪进行了两部分实验：（1）对鸡蛋壳分别选用无掺杂、掺10%Na2CO3和掺10%Li2CO3的三种掺杂方式，研究不同掺杂剂对吸收剂循环特性影响的实验；（2）对鸡蛋壳分别选用掺10%Li2CO3、掺20% Li2CO3和掺30%的Li2CO3的三种掺杂方式，研究掺杂剂比例对吸收剂循环特性影响的实验。研究发现：掺杂Li2CO3和Na2CO3对利用鸡蛋壳作为前驱体制备的钙基CO2吸收剂而言，碳酸化转化率、CO2吸收量、吸附能力(累计吸附量)、循环稳定性和

循环吸收能力均有促进作用，而且对抗烧结能力也有增强效果。对于利用鸡蛋壳作为前驱体制备的钙基CO2吸收剂，相较于掺10%Na2CO3，掺10%Li2CO3的吸收剂在碳酸化反应中（捕集CO2方面）效果更佳；相较于掺Li 10%Li2CO3，掺10% Na2CO3的吸收剂在煅烧分解反应中（释放CO2方面）效果更佳；在CO2吸收量、吸附能力(累计吸附量)、循环吸收能力等方面，掺20% Li2CO3的效果强于掺30%的，掺30%的效果又明显强于掺10%的；在碳酸化转化率和循环稳定性方面，掺20% Li2CO3的效果只是略微强于掺30% Li2CO3的；在碳酸化转化率方面，掺20%和30%Li2CO3的都明显强于只掺10%

Li2CO3的；在循环稳定性方面，掺20%和30%Li2CO3的却都明显弱于只掺10% Li2CO3的。

关键词：掺杂剂；钙基吸收剂；CO2；热重分析法

Abstract

With the rapid development of society and industry, the impact of greenhouse gases such as CO2 on global ecological environment is becoming more and more serious.Calcium-based adsorbents have attracted much attention from carbon capture researchers because they capture CO2 well and release high-purity CO2 when needed.However, the cyclic characteristics of calcium-based absorbers are also limited, such as high-temperature sintering of CaO, encapsulation of the absorbent by the product CaCO3, etc., and their absorption capacity will be greatly reduced after multiple cycles of CO2 absorption.Therefore, it is very important to modify the calcium-based absorber, in which doping modification becomes more and more important.

In this paper, the current status of carbon dioxide capture and calcium-based modification at home and abroad is elaborated, and the principle of cyclic carbon dioxide capture by calcium-based absorbers and the reasons for decay of cyclic carbon capture performance of absorbers are analyzed.Based on this, the author used common waste eggshell as precursor to prepare calcium-based absorber samples by high-temperature solid-phase method and carried out two parts of experiments with the help of thermogravimetry analyzer: (1) three doping modes of eggshell, namely, doping without doping, doping with 10%

Na2CO3 and doping with 10% Li2CO3, were selected to study the effects of different dopants on the absorption cycle characteristics; (2) experiments on eggsThe shell is doped with 10% Li2CO3, 20% Li2CO3 and 30% Li2CO3 respectively to study the effect of doping ratio on the absorption cycle characteristics.It is found that doping with Li2CO3 and Na2CO3 promotes the carbonation conversion, CO2 absorption, adsorption capacity (accumulated adsorption), cyclic absorption and cyclic stability of calcium-based CO2 absorbers prepared by using eggshell as precursor, and also enhances the sintering resistance.For calcium-based CO2 absorber prepared by using eggshell as precursor, 10% Li2CO3 is better than 10% Na2CO3 for carbonation (CO2 capture); 10% Li2CO3 is better than Li 10% Li2CO3 for

carbonation.Absorbent Na2CO3 has better effect in calcination decomposition reaction (releasing CO2); in terms of CO2 absorption, adsorption capacity (accumulative adsorption), cycle stability, etc., the effect of 20% Li2CO3 is stronger than that of 30% and 30% is