二氧化碳捕集论文：蜂窝状活性炭吸附CO2及电解吸过程的研究

二氧化碳捕集论文：蜂窝状活性炭吸附CO2及电解吸过程的研究【中文摘要】随着哥本哈根会议的召开与京都议定书的生效,特别是近期南非德班气候大会的顺利闭幕,国际CO2减排形势日益严峻,减缓温室效应、对CO2实施减排已经刻不容缓。本文拟采用低压降蜂窝状活性炭吸附捕集烟道气中的CO2,并利用蜂窝状活性炭良好的导电导热性能,研发先进的电解吸技术,取代传统的真空解吸工艺。估算捕集CO2过程的能耗,为蜂窝状活性炭吸附捕集温室气体CO2的工业应用提供基础依据。蜂窝状活性炭不仅具有比表面积高、孔隙结构可控的优点,还具有开孔率高、压降低、吸脱附速率快、机械强度高、不易堵塞等优点,因此被认为是捕集烟道气中C02重要吸附剂。本文选用商业可得到的蜂窝状煤基活性炭和蜂窝状椰壳活性炭吸附捕集烟道气中CO2,并采用K2CO3溶液浸渍蜂窝状活性炭,提高吸附烟道气中低浓度C02的容量和增加CO2/N2的选择性。利用磁悬浮天平测定了K2CO3溶液浸渍前后蜂窝状活性炭吸附C02和N2的平衡等温线；采用Langmuir、Multi-site Langmuir和Virial模型对CO2和N2的吸附平衡实验数据进行拟合；比较了K2CO3溶液浸渍前后蜂窝状活性炭吸附CO2容量、CO2/N2选择性以及吸附热,为吸附工艺的优化设计提供基础数据。优化设计蜂窝状活性炭填充床,解决吸附剂与吸附器的良好匹配,提高电加热时能量的利用率。建立了蜂窝状活性炭导电导热性能测试装置,实验测量电加热时吸附器内蜂窝状活性炭的电流、电阻变化曲线及温升曲线,计算电加热每公斤吸附材料需要的能耗,讨论电能的有效利用率。实验研究蜂窝状活性炭吸附捕集烟道气中CO2及其电解吸过程,研究捕集CO2的操作条件,如进气C02浓度、解吸温度、解吸时间、吹扫气速等对烟道气C02回收率、产品气CO2纯度、吸附剂再生率以及过程能耗的影响。核算捕集每公斤CO2所需要的能耗,探讨电解吸工艺可行性。总之,研发新型的、导电导热性能良好的、高效CO2吸附材料；解决吸附剂与吸附器的良好匹配,提高电加热时能量的利用率；优化CO2吸附及电解吸过程,降低捕集烟道气中CO2成本及能耗,将使电解吸工艺在CO2吸附捕集技术中发挥显著的优势。【英文摘要】With Copenhagen conference, Kyoto Protocol and Durban climate conference, the greenhouse effect which caused great environmental problems has become one of the most important issues in the world. The massive emission of CO2 during the combustion of fossil fuels was considered as the important contribution. So the effective measures must be taken to reduce the emission of CO2 from the flue gas. In this paper, activated carbon (AC) monoliths were used as adsorbents to capture CO2 from the flue gas. Based on the good electrothermal behavior of AC monolith, the electrothermal desorption process for the adsorbent regeneration was developed, instead of the traditional vacuum desorption process. The feasibility and efficiency of the process for CO2 capture by AC monolith adsorption with the electrothermal desorption were evaluated.AC monolith had the advantages of high specific surface area, controllable pore structure, high adsorption and desorption rates, low pressure drop as well as excellent mechanical strength. So it was generally considered as a promising adsorbent material to capture CO2. In this paper, two commercially available coal/coconut AC monoliths were used as adsorbents to capture CO2 from flue gas. Moreover, these adsorbent materials were soaked in K2CO3 solution to improve the CO2 adsorption capacity and the CO2/N2 selectivity.Adsorption equilibrium isotherms of CO2 and N2 on coal/coconut AC monoliths (before/after soaking in K.2CO3 solution) were measured using the magnetic suspension balance instrument. The experimental data were fitted with Langmuir、Multi-site Langmuir and Viral models, respectively. The CO2 adsorption capacity, the CO2/N2 selectivity and the adsorption heat on AC monoliths (before/after soaking with K2CO3 solution), were calculated and compared with each other, to get the basic parameters for the design and optimization of the adsorption process.Since the AC monolith had a good electrical conductivity, the electrothermal desorption process was developed for the regeneration of adsorbents. AC monolith was packed in a column with the electricity heating system, and the electrical current /resistance and temperature curves in the packed bed were measured to calculate the energy consumption per kilogram of adsorbents when heating with electricity. The utilization efficiency of the electrical energy was discussed.The CO2 adsorption and electrothermal desorption of adsorbents were investigated. The effects of operation conditions, such as CO2 inlet concentration in feed、desorption temperature、purge gas velocity and heating voltage were investigated. The energy consumption to capture one kilogram CO2 was calculated, and the feasibility and efficiency of the electrothermal desorption process was evaluated.In conclusion, with the development of new adsorbent materials having good electrothermal conductivity and high CO2 adsorption capacity, the optimal design of adsorber with electricity heating system, the optimization of the adsorption/electrothermal desorption process, the energy consumption and cost for CO2 capture could be reduced, that would make the electrothermal desorption process more promising.【关键词】二氧化碳捕集 二氧化碳吸附 电解吸 蜂窝状活性炭 吸附剂改性【英文关键词】Carbon dioxide capture Carbon dioxide adsorption Electrothermal desorption AC monolith Adsorbent modification【备注】索购全文在线加好友：1.3.9.9.3.8848 同时提供论文写作一对一指导和论文发表委托服务【目录】蜂窝状活性炭吸附CO2及电解吸过程的研究摘要5-6Abstract6-7第1章 前言10-121.1 研究背景10-111.2 主要研究内容11-12第2章 二氧化碳吸附材料及工艺综述12-282.1 温室效应的影响122.2 二氧化碳的减排12-162.2.1 CO_2的减排措施12-132.2.2 二氧化碳的捕集13-152.2.3 二氧化碳的封存152.2.4 国内外CO_2减排的现状15-162.3 CO_2分离回收技术16-202.3.1 吸收法17-182.3.2 吸附法18-192.3.3 膜分离法19-202.3.4 低温蒸馏法(深冷分离法)202.4 吸附工艺简介20-242.4.1 变压吸附(PSA)20-212.4.2 变温吸附(TSA)212.4.3 电解吸工艺(ESA)21-242.5 吸附材料24-282.5.1 碳基材料24-252.5.2 碳材料改性25-28第3章 蜂窝状活性炭吸附CO_2/N_2平衡等温线28-473.1 蜂窝状活性炭28-293.1.1 蜂窝状活性炭28-293.1.2 K_2CO_3浸渍蜂窝状活性炭293.2 蜂窝状活性炭表征29-303.3 吸附等温线理论模型30-323.3.1 Langmuir模型303.3.2 Multi-site Langmuir模型30-313.3.3 Viral模型31-323.4 吸附等温线的测定32-343.4.1 测定原理323.4.2 实验测量步骤32-343.5 结果与讨论34-383.5.1 比表面积和孔径结构表征34-353.5.2 SEM分析35-363.5.3 红外分析36-373.5.4 元素分析37-383.6 蜂窝碳材料上CO_2/N_2吸附平衡的比较38-393.7 吸附等温线的拟合39-453.7.1 CO_2/N_2在蜂窝碳上的吸附平衡及拟合39-453.8 小结45-47第4章 蜂窝状活性炭导电导热性能的研究47-544.1 实验装置47-484.2 实验内容及能耗计算方法484.3 实验结果与讨论48-534.3.1 蜂窝状煤基活性炭的导电导热性48-504.3.2 蜂窝状煤基活性炭能耗计算50-514.3.3 蜂窝状椰壳活性炭的导电导热性及能耗计算51-534.4 小结53-54第5章 蜂窝状活性炭吸附CO_2及电解吸过程的研究54-785.1 实验装置流程54-565.2 动态CO_2吸附/电解吸实验565.3 蜂窝状煤基活性炭吸附CO_2及电解吸过程56-685.3.1 进料浓度对CO_2吸附容量的影响56-585.3.2 进料浓度对电解吸过程及能耗