Enhancement Effect of Ordered Hierarchical Pore Configuration on SO2 Adsorption and Desorption Process

Abstract

Carbonaceous adsorbents with both high sulfur capacity and easy regeneration are required for flue gas desulfurization. A hierarchical structure is desirable for SO2 removal, since the micropores are beneficial for SO2 adsorption, while the mesopore networks facilitate gas diffusion and end-product H2SO4 storage. Herein, an ordered hierarchical porous carbon was synthesized via a soft-template method and subsequent activation, used in SO2 removal, and compared with coal-based activated carbon, which also had a hierarchical pore configuration. The more detailed, abundant micropores created in CO2 activation, especially the ultramicropores (d < 0.7 nm), are essential in enhancing the SO2 adsorption and the reserves rather than the pore patterns. While O2 and H2O participate in the reaction, the hierarchical porous carbon with ordered mesopores greatly improves SO2 removal dynamics and sulfur capacity, as this interconnecting pore pattern facilitates H2SO4 transport from micropores to mesopores, releasing the SO2 adsorption space. Additionally, the water-washing regeneration performances of the two types of adsorbents were comparatively determined and provide a new insight into the mass-transfer resistance in the pore structure. The ordered hierarchical carbon promoted H2SO4 desorption efficiency and cycled SO2 adsorption–desorption performance, further indicating that interconnecting micro- and mesopores facilitated the diffusion of adsorbates.

Special Issue on “Energy, Economy and Environment for Industrial Production Processes”

“…Hence, they introduce a new method for producing high-value chemical raw material by the catalytic cracking of waste tires with spent FCC catalysts. Zhu et al [23] study the enhancement effect of ordered hierarchical pore configuration on the SO 2 adsorption and desorption process. Their results show that the ordered hierarchical carbon can promote H 2 SO 4 desorption efficiency and cycled SO 2 adsorption-desorption performance, further indicating that interconnecting micro and mesopores facilitates the diffusion of adsorbates.…”

Effect on Combustion Properties of Coal Treated by Microwave Irradiation Combined with Sodium Hydroxide Solution

“…Sulfur is one of the harmful elements that will combine with oxygen and release sulfur oxides during combustion [3]. These sulfur oxides contribute to particulate matter (PM) and acid rain can affect human health and the environment [4,5]. In order to use coal cleanly and environmentally friendly, coal desulfurization has been attracted the attention of many researchers.…”

NO2–NH3 SCR over Activated Carbon: A Combination of NH4NO3 Formation and Consumption

“…In recent years, carbon-based materials, especially activated carbon (AC) with a high specific surface area − and the possibility of modifying surfaces by introducing heteroatoms or metals/metal oxides, − have been widely used for NO–NH 3 SCR reactions, showing exceptional catalytic activity, − especially at low temperatures. Thus, AC has been applied to the NO purification of coal-fired flue gas. , Based on the superior performance of AC materials in terms of NO–NH 3 SCR, Gao et al studied the catalytic properties of NO x –NH 3 SCR with the addition of NO 2 over a V 2 O 5 /AC catalyst in the temperature range of 100–300 °C.…”