CO_2 capture performance of bi-functional activated bleaching earth modified with basic-alcoholic solution and functionalization with monoethanolamine: isotherms, kinetics and thermodynamics  

作　　者：Sangobtip Pongstabodee Phuwadej Pornaroontham Nuthapol Pintuyothin Nuttapol Pootrakulchote Nutthavich Thouchprasitchai 

机构地区：[1]Department of Chemical Technology, Faculty of Science, Chulalongkorn University [2]Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University

出　　处：《Journal of Environmental Sciences》2016年第10期126-137,共12页环境科学学报（英文版）

基　　金：financially supported by the annual government statement of expenditure;the in-depth research cluster project of Chulalongkorn University (Energy cluster);the Thailand Research Fund (No. IRG5780001);Chulalongkorn University;Faculty of Science of Chulalongkorn University;Rachadapisek Sompote Fund for Postdoctoral Fellowship, Chulalongkorn University

摘　　要：CO2 capture performance of bifunctional activated bleaching earth （ABE） was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET）, Caron-Hydrogen-Nitrogen analysis （CHN）, Fourier transform infrared （FT-IR） and thermal gravimetric analysis （TGA）. The CO2 capacity was enhanced uia basic-modification and monoethanolamine （MEA） loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30 wt.% MEA loading （SAB-30） showed the highest CO2 capture capacity, but this was decreased with excess MEA loading （〉 30 wt.%）. At a 10% （V/V） initial CO2 concentration feed, the maximum capacity of SAB-30 increased from 2.71 mmol/g at 30~C {without adding moisture to the feed） to 3.3 mmol/g at 50℃ when adding 10% （V/V） moisture to the feed. Increasing the moisture concentration further reduced the maximum CO2 capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture COg even in a 100% （V/V） initial CO2 concentration feed. A maximum CO2 capacity of 5.7 mmol/g for SAB-30 was achieved at 30℃. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO2 capture capacity. Avrami＇s equation and Toth＇s isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO2 capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO2 capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.CO2 capture performance of bifunctional activated bleaching earth （ABE） was investigated at atmospheric pressure. The sorbents were characterized by means of X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET）, Caron-Hydrogen-Nitrogen analysis （CHN）, Fourier transform infrared （FT-IR） and thermal gravimetric analysis （TGA）. The CO2 capacity was enhanced uia basic-modification and monoethanolamine （MEA） loading of the ABE sorbent to obtain a bifunctional surface property. Here, basic-modified calcined ABE with a 30 wt.% MEA loading （SAB-30） showed the highest CO2 capture capacity, but this was decreased with excess MEA loading （〉 30 wt.%）. At a 10% （V/V） initial CO2 concentration feed, the maximum capacity of SAB-30 increased from 2.71 mmol/g at 30~C {without adding moisture to the feed） to 3.3 mmol/g at 50℃ when adding 10% （V/V） moisture to the feed. Increasing the moisture concentration further reduced the maximum CO2 capacity due to the blocking effect of the excess moisture on the sorbent surface. However, SAB-30 could completely capture COg even in a 100% （V/V） initial CO2 concentration feed. A maximum CO2 capacity of 5.7 mmol/g for SAB-30 was achieved at 30℃. Varying the ratio of sorbent weight to total flow rate of the gas stream had no discernible effect on the equilibrium CO2 capture capacity. Avrami＇s equation and Toth＇s isotherm model provided a good fitting for the data and suggested the presence of more than one reaction pathway in the CO2 capture process and the heterogeneous adsorption surface of SAB-30. Thermodynamics studies revealed that CO2 capture on the bifunctional SAB-30 is feasible, spontaneous and exothermic in nature.

关 键 词：Carbon dioxideCaptureActivated bleaching earthBifunctional surface 

分 类 号：X701[环境科学与工程—环境工程]