Hydrogen production from CO2 reforming of methane over high pressure H2O2 modified different semi-cokes

Guojie Zhang,Jiangwen Qu,Yannian Du,Fengbo Guo,Haixiang Zhao,Yongfa Zhang,Ying Xu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

H2O2 was used under different temperatures and pressures to activate three kinds of different semicokes. FTIR, BET, SEM and Boehm titration were used to analyze properties of the semi-cokes surfaces, finding that catalytic activities of these semi-cokes after modification by high temperature and high pressure H2O2 were improved. FTIR shows that the characteristic infrared absorption peak of functional groups on the semi-cokes surface does not change, but the absorption peak intensity of some functional groups is increased. The strength of –OH absorption peak of Hongce lignite (HCL) semi-coke at 3444 cm-1, carboxyl C55O at 1598 cm-1, aliphatic ether, cyclic ether and other organic functional groups at 1023 cm 1 in the modified Shenmu bituminous(SMB) semi-coke and Jincheng anthracite (JCA) semicoke are increased significantly. BET finds that the specific surface area and pore volume of three semicokes are increased after modification. Boehm titration shows that the basic functional group content in semi-coke is increased after modification, and the net alkali content is increased significantly. Compared with the raw semi-coke, SEM shows that the surface of semi-coke modified with H2O2 becomes rough. Modified JCA semi-coke surface pitted with holes, modified HCL and SMB semi-coke surface present porous.

Towards understanding the carbon catalyzed CO2 reforming of methane to syngas

Guojie Zhang,Jiangwen Qu,Aiting Su,Yongfa Zhang,Ying Xu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

In this paper, a fixed-bed reactor is used to study the influence of different conditions on carboncatalyzed CO2–CH4 reforming. The surface structure and functional groups of carbonaceous materialhave been characterized through SEM, XPS, XRD, BET and chemical titration before and after the reaction. Studies have revealed that under non-catalytic condition, methane pyrolysis happens first, followed bythe gasification reaction between CO2 and carbon deposit produced from the pyrolysis. While withcarbonaceous material, CO2 gasification, methane pyrolysis and CO2–CH4 reforming can take place at thesame time, with the reforming as the main reaction, CO2 gasification and methane pyrolysis as the sidereaction. Catalytic activity varies from one carbonaceous material to another, but their reaction trend isthe same on the whole. Those high specific surface area carbonaceous materials show higher catalyticactivity. The increase in reaction temperature and residence time of the reforming can improve theconversion of reactant gas. Adjusting the partial pressure of methane can control carbon–hydrogen ratio ofthe synthesis gas. XPS and XRDcharacterizationsdemonstrate that the structural ordering of carbonaceousmaterials becomes a little messier after the reforming reaction, and the number and content of oxygenfunctional groups decrease. That means these oxygen functional groups on the surface of carbonaceousmaterials are involved in the reforming and these groups along with pore structure on the surface are themajor factors influencing the catalytic properties. Different oxygen species make the nature of electricalenergy on the surface different; the catalytic activity depends on the polarity of oxygen from differentspecies. Those whose polarity is strong have strong activity. The dipole force can be associated withmethane in the form of hydrogen bond, so that the material can display strong activity. Those whosepolarity is weak have weak activity, the catalytic activity is weak too. The results of chemical titration andXPS characterization show that the oxygen in the anhydride and lactone structures on the surface ofcarbonaceous materials are active oxygen, and which is the main active component, it can reduce theactivation energy of methane dehydrogenation.

Development of amine-functionalized hierarchically porous silica for CO2 capture

Guojie Zhang,Peiyu Zhao,Ying Xu 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A kind of hierarchical porous silica (HPS) was synthesized in a relatively mild condition and then devoted as the supports to fabricate TEPA-impregnated adsorbents for CO2 adsorption. HPS has different pore size distribution and the huge pore volume. These structure characteristics of HPS can mitigate the mass transfer resistance which occurs more serious in traditional carrier materials with single smaller channel. The CO2 adsorption performances of modified HPS were investigated in a homemade fixed bed reactor under different conditions. The HPS exhibited maximum CO2 adsorption capacities of 5.01 mmol/g when 60 wt.% TEPA loaded. It presented better TEPA loading properties and higher CO2 adsorption capacities than the majority of the single ordered mesoporous adsorbents according to the literature. When the adsorption experiments were repeated ten times, the amount of CO2 capture reduces from 5.01 mmol/g to 4.7 mmol/g, only 6.1% reduction. And the deactivation model which can describe the absorption of CO2 was adopted under different experiment conditions. In all these cases, the experimental data of CO2 adsorption gave a good agreement with the predicted results by the breakthrough model.

Effects of preparation methods on the properties of cobalt/carbon catalyst for methane reforming with carbon dioxide to syngas

Guojie Zhang,Yongfa Zhang,Yannian Du,Ying Xu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

The effect of different preparation methods on the physicochemical property, reforming reactivity, stability and carbon deposition resistance of cobalt/carbon catalyst was investigated through fixed bed flow reaction. The catalysts were prepared by the impregnation and characterized by the XRD and scanning electron microscopy (SEM). The result indicated that the active components of cobalt/carbon catalyst prepared by using ultrasonic wave distributed evenly, activity was high and the loading time was short. The Co/Carbon catalyst prepared by incipient-wetness impregnation, 10 wt% loading and 300 ℃ calcination, achieved the best activity. Furthermore, the effect of reaction temperature, air speed and CH4/CO2 ratio on the catalyst activity and CO/H2 ratio in products was investigated. It was found that the conversion of CO2 and CH4 increased with the increasing of reaction temperature. However, the conversion of CO2 and CH4 increased first and then decreased with the increasing of air speed. With the increasing of CH4/CO2 in feed gas, both the catalyst activity and the CO/H2 ratio in products decreased.

Structural, Morphological, and Optical Studies on Li-doped ZnO Thin Films Deposited by Using PLD

Guojie Li,S. Sambasivam,Saes Byul Kim,박성욱,정중현,전병억,최병춘 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.4

We report the structural and the optical properties of Zn_(1−x)Li_xO (x = 0.0, 0.02, 0.08, 0.12, 0.18) nanocrystalline thin films deposited on ?Al_2O_3 substrates by using pulsed laser deposition. X-ray diffraction (XRD) analysis revealed that all the films were single phase and had a hexagonal wurtzite structure. The lattice constant increased gradually with increasing Li content. Atomic force microscopy (AFM) showed that the grain size of the films was approximately 20 ?30 nm. Optical absorption studies in the wavelength range 200 ?900 nm revealed an increase in the band gap of the Li-doped ZnO films from 3.19 to 3.41 eV. Photoluminescence (PL) spectroscopy of these films was carried out. The luminescence observed was attributed to defects in the nanocrystalline Li-doped ZnO films, and the PL intensity decreased with increasing Li content.

Desulfurization reaction model and experimental analysis of high sulfur coal under hydrogen atmosphere

Guojie Zhang,Yannian Du,Yongfa Zhang,Ying Xu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.2

The reaction between hydrogen and high-sulfur coal at high temperature was investigated. Crashed andsieved high-sulfur coal sample was placed in a 23 mm I.D. differential reactor. The release of hydrogensulfide at run temperature and under different hydrogen atmospheres was recorded by a hydrogensulfide detector. Desulfurization yield was obtained through the elemental analysis of residual char. Thegrain reaction and random pore models were modified to facilitate the description of reaction kineticscharacteristics. Hydrogen was observed to promote the desulfurization rate considerably; i.e., more than65% of sulfur in coal could be removed. The releasing curves of H2S in the hydropyrolysis processexhibited two peaks. The desulfurization process in the hydropyrolysis of high-sulfur coal could beregarded as two stages based on the evolution profiles of H2S. The first peak at 250–450℃ was derivedfrom the desulfurization of aliphatic sulfide. The second peak at 450–650℃ was produced from thesulfur in pyrite and aromatic thiophenic structure. The desulfurization of high sulfur could be describedmore effectively with the grain reaction model than with the random pore model. The random poremodel was only adopted in the initial stage of sulfur removal of high-sulfur coal under hydrogenatmosphere. The grain reaction model was adequate for the entire stage.

Dielectric and p-type Characteristics of Li-doped ZnO Thin Films

Guojie Li,최병춘 한국물리학회 2014 새물리 Vol.64 No.7

We report the structural, dielectric and electronic properties of Zn1−xLixO (x = 0.1, 0.05, 0.10) thin films prepared on Pt(111)/Ti/SiO2/Si substrates by using pulsed laser deposition (PLD). Xray diffraction (XRD) analyses revealed that all of films had a single phase as the Zn-O bond length gradually increased with increasing Li content at first and then decreased after a certain threshold. 5-at% and 10-at% Li-doped ZnO thin films show p-type behavior based on Hall-effect measurements. The existence of defects, such as Lii (interstitial Li) and LiZn (substitutional Li at the Zn site), should be considered in the host materials. The relationship between the defects and the Li concentration is consistent with the dielectric results. The stabilization of p-type thin films as to the behavior of defects is also discussed theoretically.

Simulation and Experiment on Direct Continuous Casting Process of Lead Frame Copper Alloy

Huang Guojie,Xie Shuisheng,Cheng Lei 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Direct Continuous Casting (D.C.C) is an important method in casting lead frame copper alloy. In this paper, numerical simulation is adopted to investigate the casting process in order to optimize the D.C.C technical parameters, such as the casting temperature, casting speed and cooling intensity. According to the numerical results, the reasonable parameters are that the casting temperature is between 1413K~1413K, the casting speed is between 8m/h~10m/h and the speed of cooling water is between 4.2m/s~4.6m/s. And the depth of liquid-solid boundary is measured in different casting temperature and casting speed by experiments. The results show the actual measurements have a little deviation with the numerical simulation. The results of numerical simulation provide the significant reference to the actual experiments.

Rate-based Modeling and Tec hno-Economic Analysis of a Pilot-Scale SMR Purge Gas Carbon Capture Process in a Chinese Refinery Plant

Shujuan Wang,Guojie Qi,Yongkang Cui,Lizhen Xu 한국에너지기후변화학회 2023 한국에너지기후변화학회 학술대회 Vol.2023 No.5

Treatment of Domestic Wastewater Mixed with Crushed Garbage and Garbage Washing Water by Advanced Gappei - shori Johkaso Systems

( Toshihiro SANKAI,Guoji DING,Noritoshi EMORI,Satoshi KITAMURA,Kensho KATADA,Akihiko KOSHIO,Tatsushi MARUYAMA,Keiko KUDOU,Yuhei INAMORI ) 한국물환경학회 1997 제6차 국제수질보전학회 아시아 태평양지역 학술회의 Vol.1 No.-