Adsorption and reaction mechanism, of arsenic vapors over γ-Al2O3 in the simulated flue gas containing acid gases

被引：53

作者：

Hu, Hongyun ^{[1
]}

Chen, Dunkui ^{[1
]}

Liu, Huan ^{[1
,2
]}

Yang, Yuhan ^{[1
]}

Cai, Hexun ^{[1
]}

Shen, Junhao ^{[1
]}

Yao, Hong ^{[1
,2
]}

机构：

[1] Huazhong Univ Sci & Technol, Sch Energy & Power Engn, State Key Lab Coal Combust, Wuhan 430074, Peoples R China

[2] Huazhong Univ Sci & Technol, Sch Energy & Power Engn, Dept New Energy Sci & Engn, Wuhan 430074, Peoples R China

来源：

CHEMOSPHERE | 2017年 / 180卷

基金：

中国博士后科学基金; 中国国家自然科学基金;

关键词：

Arsenic adsorption; gamma-Al2O3; Acid gases; Species; Regeneration; HYDROTALCITE-LIKE COMPOUNDS; PULVERIZED COAL COMBUSTION; CO2; CAPTURE; FLY ASHES; SO2; TRANSFORMATION; SPECIATION; REMOVAL; SURFACE; TEMPERATURE;

D O I：

10.1016/j.chemosphere.2017.03.114

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Arsenic emission from fuel combustion and metal smelting flue gas causes serious pollution. Addition of sorbents is a promising way for the arsenic capture from high temperature flue gas. However, it is difficult to remove arsenic from SO2/HCl-rich flue gas due to the competitive reaction of the sorbents with arsenic and these acid gases. To solve this problem, arsenic adsorption over gamma-Al2O3 was studied in this work to evaluate its adsorption mechanism, resistance to acid gases as well as regeneration behavior. The results show that gamma-Al2O3 had good resistance to acid gases and the arsenic adsorption by gamma-Al2O3 could be effectively carried out at a wide temperature range between 573 and 1023 K. Nevertheless, adsorption at higher-temperature (like 1173 K) leaded to the decrease of surface area and the rearrangement of crystal structure of gamma-Al2O3, reducing the active sites for arsenic adsorption. The adsorption of arsenic was confirmed to occur at different active sites in gamma-Al2O3 by forming various adsorbed species. Increasing temperature facilitated arsenic transformation into more stable chemisorbed As3+ and As5+ which were difficult to remove through thermal treatment regeneration. Fortunately, the regeneration of spent gamma-Al2O3 could be well performed using NaOH solution. (C) 2017 Elsevier Ltd. All rights reserved.

引用

页码：186 / 191

页数：6

共 33 条

[31] Arsenite and arsenate adsorption on coprecipitated bimetal oxide magnetic nanomaterials: MnFe2O4 and CoFe2O4 [J].