Behavior of mercury release during thermal decomposition of coals

Shaoqing Guo,Yong Xiao,Jianli Yang,Zhenyu Liu 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.2

The mercury release behavior during thermal decomposition of three Chinese coals with different types was studied under nitrogen, carbon dioxide and air at temperatures of 800, 900, 1,000 and 1,100℃. The thermal treatment experiments were carried out in a quartz tube reactor. Results showed that the release ratio of total mercury during thermal decomposition of coals increases with the increasing temperature. The order of the amount of mercury released under the three atmospheres is nitrogen<carbon dioxide<air for all three coals during thermal decomposition. This indicates that air and carbon dioxide can promote the mercury release due to their reactivity with coal. However, the order of amount of elemental mercury released under the three atmospheres is nitrogen>carbon dioxide>air for all three coals. The release behavior of the total mercury under air is independent of the coal type. Under the other two atmospheres the release behavior is distinguished by the coal type.

The catalytic performance of methylation of naphthalene with methanol over SAPO-11 zeolites synthesized with different Si content

Shaoqing Guo,Liangfu Zhao,Xiaoxiao Wang,Fang Guo,Xianxian Wei,Zhenmin Liu,Wei Zhang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7

A series of SAPO-11 zeolites with different Si contents were prepared by hydrothermally synthesized method. They were characterized by ICP, XRD, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD and 29Si MAS NMR, and evaluated by the methylation of naphthalene with methanol to 2,6-dimethylnaphthalene (2,6-DMN). According to XRD and SEM results, the crystallinity of SAPO-11 sample increased with increase of the Si content until the SiO2/Al2O3 ratio was up to 0.2. However, a reduction in the crystallinity was observed with further increase of the Si content of the synthesis. N2 adsorption-desorption results showed that all the samples possessed micropores and secondary mesopores. SAPO-11 sample with SiO2/Al2O3 ratio of 0.2 exhibited the largest secondary mesopores size distributions. NH3-TPD and 29Si MAS NMR showed that the Si content was incorporated into the framework affecting not only the acid sites but also the acid strength of SAPO-11. SAPO-11 with SiO2/Al2O3 ratio of 0.2 presented the high catalytic performances for the methylation of naphthalene, which was mainly attributed to the amount of secondary mesopores in the SAPO-11 zeolite.

The effects of MCM-41’s calcination temperature on the structure and hydrodenitrogenation over NiW catalysts

Fang Guo,Zegang Qiu,Liangfu Zhao,Shaoqing Guo,Xian-Xian Wei,Xiaoxiao Wang,Hongwei Xiang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.11

MCM-41 was calcined at 500, 560, 600 or 650 oC. It was used as support for NiW catalysts of hydrodenitro-genation (HDN) for quinoline in order to investigate the influences of the MCM-41’s calcination temperature on thestructure and the HDN performance of NiW catalysts. The NiW catalysts were characterized by XRD, N2 adsorption-desorption, XPS, Raman, HRTEM and Py-IR techniques. The results showed that the surface area (SBET), the averagepore diameter (Dp) and the pore volume (Vp) of the MCM-41 increased with increase of the MCM-41’s calcinationtemperature. The high SBET , Dp and Vp were beneficial for the high dispersion of W species, the formation of appropriatenature of W species and acid sites on the catalysts. The HDN activity followed the order of NiW-650≈NiW-600>NiW-560>NiW-500, while the relative selectivity of HDN pathways was similar for all the catalysts.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

Wang, Xiaoxiao,Guo, Shaoqing,Zhao, Liangfu Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

$H{\beta}$ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of $H{\beta}$ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of $H{\beta}$ and SAPO-11. The physicochemical properties of $H{\beta}$, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that $H{\beta}$/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the $H{\beta}$ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of $H{\beta}$ and SAPO-11. The composite had fewer acid sites than $H{\beta}$ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

Xiaoxiao Wang,Shaoqing Guo,Liangfu Zhao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Hβ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of Hβ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of Hβ and SAPO-11. The physicochemical properties of Hβ, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that Hβ/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the Hβ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of Hβ and SAPO-11. The composite had fewer acid sites than Hβ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Imidazole derivatives for efficient organic light-emitting diodes

Ye Shaofeng,Zhuang Shaoqing,Pan Biao,Guo Runda,Wang Lei 한국정보디스플레이학회 2020 Journal of information display Vol.21 No.3

Since the first development of organic light-emitting diodes (OLEDs) in 1987, imidazole derivatives, mainly including phenanthroimidazole (PI) and benzimidazole (BI), have increasingly attracted attention. Their strong electron-withdrawing properties make them suitable for emitters, hosts, and electron-transporting materials (ETMs). In this review, an overview of the recent developments regarding OLEDs based on imidazole derivatives, especially the relationship between the molecule structure and the device performance as fluorescent and host materials, is given.

Effect of Thread Count on the Shear Mechanical Properties and Dynamic Mechanical Properties of Shape Memory Polymer Reinforced by Single-Ply Weave Fabric

Peng Qu,Guangqiang Fang,He Kong,Zhengli Cao,Jia Ma,Zhiyi Wang,An-Fu Guo,Shaoqing Wang,Xunjin Li,Xinran Shan 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

Shape memory epoxy polymer reinforced by single-ply weave fabric (SMEP-W) possesses high specific stiffness, good foldability, and satisfactory shape memory capability. These advantages make them promising materials for deployable space structures and increasingly attract research interests. Understanding the influence of weave structures on static and dynamic mechanical properties is crucial to structural design and mechanical response prediction. In this paper, a recently developed SMEP-W was prepared. The static shear experiments were conducted through modified shear test fixtures, and the stress field under static shear load was simulated through a multi-scale numerical modelling method. The dynamic mechanical analysis was carried out to evaluate the shape memory capability. SMEP-W shows nonlinear mechanical behavior under in-plane shear load, especially for the one with less thread count. The increase in the number of threads enhances the constraints between warp yarns and weft yarns, leading to an increase in shear modulus and reducing the scattering of static mechanical properties. The stress distribution on the yarns has the characteristic of center symmetry. High-stress regions appear on the overlapping surface of the crossover regions. Compared with shape memory epoxy polymer (SMEP), the glass transition temperature and damping coefficient of SMEP-W are significantly reduced, and the stiffness is remarkably enhanced. The difference in thread count between warp direction and weft direction does not notably affect the glass transition temperature and tan δ, but has a remarkable influence on the storage modulus. The present work could provide basic observation for understanding the influence of thread count on the shear mechanical properties and dynamic mechanical properties of SMEP-W.