Applied Surface Science 258 (2012) 6943–6951 Contents lists available at SciVerse ScienceDirect Applied Surface Science j our nal ho me p age: www.elsevier.com/loc ate/apsusc Pilot-scale production of mesoporous silica-based adsorbent for CO 2 capture Hou Chuan Wang a , Chungsying Lu b,∗ , Hsunling Bai c , Jyh Feng Hwang a , Hsiu Hsia Lee a , Wang Chen a , Yuhao Kang a , Shing-Ting Chen a , Fengsheng Su b , Shih-Chun Kuo b , Fang-Chun Hu b a Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan b Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan c Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan a r t i c l e i n f o Article history: Received 3 October 2011 Received in revised form 17 February 2012 Accepted 23 March 2012 Available online 31 March 2012 Keywords: Amine modification CO2 adsorption Spherical mesoporous silica particles Pilot-scale a b s t r a c t This study presents a pilot-scale spray drying system designed to manufacture spherical mesoporous silica particles (MSP) that is capable of producing up to 100 g per hour. The MSP fabricated via a noz- zle pressure of 4 kg/cm 2 and a drying temperature of 200 ◦ C possess a high specific area of 1012 m 2 /g, a narrow pore size distribution with an average pore diameter of 2.4 nm, and large pore volume of 0.81 cm 3 /g. They were further modified with a tetraethylenepentamine (TEPA-MSP) to enhance CO 2 adsorption selectivity from gas streams. The adsorption capacity of 15% CO 2 on TEPA-MSP was signifi- cantly influenced by adsorption temperature and water vapor of air streams, and reached a maximum of 87.05 mg/g (1.98 mmol/g) at 60 ◦ C and 129.19 mg/g (2.94 mmol/g) at a water vapor of 6.98%. The adsorp- tion capacities and the physicochemical properties of TEPA-MSP were preserved through 20 cycles of adsorption–desorption operation. A comparative study revealed that the TEPA-MSP had better adsorp- tion performance of 15% CO 2 than the TEPA-modified granular activated carbon and zeolite. These results suggest that the TEPA-MSP can be stably employed in the prolonged cyclic CO 2 adsorption and that they possess good potential for CO 2 capture from flue gas. © 2012 Elsevier B.V. All rights reserved. 1. Introduction The issue of global warming caused by the burning of fossil fuels has attracted much attention after the Kyoto Protocol came into effect on February 16, 2005. Taiwan emitted approximately 265 million tons of carbon dioxide (CO 2 ) into the atmosphere in 2006 [1]. The major anthropogenic sources of CO 2 emission include coal- fired power plants, steel plants, and cement plants. Application of CO 2 capture, utilization, and storage (CCUS) technologies on flue gas is considered to be a useful method of lessening global warning [2]. Several CO 2 capture technologies including absorption, adsorption, cryogenics, membranes and so forth, have been developed [3,4]. Among them, the design of a full-scale adsorption process might be feasible and therefore the development of a promising material that would adsorb CO 2 with a high capacity and able to be regenerated with low energy input will undoubtedly enhance the competitiveness of an adsorptive separation system in a flue gas application [5]. Low-temperature solid adsorbents reported in the literature [6,7] include physical adsorbents (carbon-based materials [8–12], zeolites [13–20] and metal organic frameworks [21–25]), amine-loaded carbons [26–30] and amine-loaded silicas [31–41]. Even though each family ∗ Corresponding author. Tel.: +886 4 22852483; fax: +886 4 22862587. E-mail address: clu@nchu.edu.tw (C. Lu). of adsorbents has its advantage; most of them were manufactured in the laboratory-scale system and commonly have an output of only several milligrams per hour. Therefore, it is necessary to increase the production rate of these adsorbents and test their performance on CO 2 adsorption before they can be employed in practical field applications. The spray drying system provides a simple means to contin- uously manufacture mesoporous silica materials, and it can be preceded at a wide range of industrial production scale. Sev- eral studies have been conducted to investigate the effects of spray-drying parameters such as the surfactant concentration, the water fraction and the gas flow on the properties of meso- porous silica materials in the laboratory-scale production [42–44]. However, limited researches have been carried out on MSPs synthesized by the pilot-scale spray drying system for the CO 2 adsorption. In this study, the spherical mesoporous silica parti- cles (MSP) was manufactured by a pilot-scale spray drying system and further modified by tetraethylenepentamine (H 2 NC 2 H 4 NHC 2 H 4 NHC 2 H 4 NHC 2 H 4 NH 2 , abbreviated as TEPA) to enhance their adsorption selectivity of CO 2 from gas streams in the 30–70 ◦ C. Cyclic CO 2 adsorption on TEPA-MSP via a ther- mal/vacuum swing operation was conducted to evaluate their repeated availability in the prolonged cyclic CO 2 adsorption. Effects of water vapor in the gas stream on CO 2 adsorption were also investigated and discussed. 0169-4332/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.apsusc.2012.03.140