One-Step Catalytic Activation Promoting Pore Development of Zhundong Coal-Based Activated Coke: A Compared Study with Conventional Carbonization–Activation Combined Process

Abstract

Hierarchically porous activated coke is widely applied in pollutant removal due to its excellent molecule adsorption and transportation ability. Catalytic activation with the participation of alkali/alkaline earth metal salt has been reported to be effective for constructing hierarchical pore configuration; however, the technical condition remains to be explored for providing guidance to practical preparation process. Herein, the relationship between the porous structure of Zhundong coal-based activated coke and the technical condition during catalytic activation is systematically discussed. Based on comparisons of porous structures obtained under different carbonization−activation conditions, one-step catalytic activation is demonstrated to be more favorable for pore development than traditional carbonization−activation process. Physicochemical structural analyses of the precursor and the prepared activated coke reveal that pore development during catalytic activation is also related to the surface chemistry of the precursor and particle size. Amplified preparation experiments in rotary kiln further verify the potential of one-step catalytic activation in industrial production. As a proof of application, selective catalytic reduction tests show that the prepared hierarchically porous activated coke via one-step catalytic activation exhibits high efficiency in NO removal. This work highlights the promoting role of one-step catalytic activation in pore development, providing guidance for preparing high-performance activated coke under practical industrial conditions.

Review on Coal-Based Activated Carbon: Preparation, Modification, Application, Regeneration, and Perspectives

“…At 675 °C, the specific surface area slightly decreased, but it rapidly increased at 800 °C, which is basically consistent with the trend in the iodine value. However, the results are inconsistent with the conclusion of Chen et al, which may be caused by the different raw materials. Chen et al selected raw materials with a high volatile content (33.52%) and strong reactivity that can undergo intense reactions at lower carbonization temperatures.…”

“…However, the results are inconsistent with the conclusion of Chen et al, which may be caused by the different raw materials. Chen et al selected raw materials with a high volatile content (33.52%) and strong reactivity that can undergo intense reactions at lower carbonization temperatures. As the heating rate increased (7, 10, and 13 °C/min), the specific surface area and iodine value showed a trend of first increasing and then decreasing, and the maximum specific surface area and iodine value were obtained at 10 °C/min.…”

“…40 In addition to the inherent characteristics of the raw materials, the carbonization temperature, heating rate (nonisothermal carbonization), and carbonization time (isothermal carbonization) are important factors that affect CAC during the carbonization process. Chen et al 47 studied the effect of different carbonization temperatures (500, 700, and 900 °C) on the pore structure of CAC, and the results showed that as the carbonization temperature increased, the specific surface area of CAC gradually decreased. In a previous study, 48 it was found that with increasing carbonization temperature, the compressive strength, wear resistance, and thermal stability of the carbonized material increased, but the yield decreased.…”

KCl/MgO Composite Templates for Achieving Hierarchical Porous Carbons with High Performance in Supercapacitor

“…From the HETEM images, it is found that the graphite layers are discontinuous for all HPCs, leading to the formation of many three‐dimensional porous structures. It should be related to the template function of MgO, while the decrease of carbon walls comes from the etching of KCl [14] . From these observations, it is confirmed that the combination of KCl and MgO can effectively promote the formation of porous and thin wall carbon structures.…”

“…It should be related to the template function of MgO, while the decrease of carbon walls comes from the etching of KCl. [14] From these observations, it is confirmed that the combination of KCl and MgO can effectively promote the formation of porous and thin wall carbon structures. Apparently, the three-dimensional porous structures with thinner wall structures are very beneficial to achieve high electrochemical performance.…”