scholarly journals Catalytic hydrolysis of Dichlorodifluoromethane over MoO3/ZrO2 -TiO2 solid acid

2020 ◽  
Author(s):  
Zhiqian Li ◽  
Tong Zhou ◽  
Guoqing Ren ◽  
Xiaofang Tan ◽  
Lijuan Jia ◽  
...  

Abstract The catalytic hydrolysis of Difluoro dichloromethane (CFC-12) by solid acid of MoO3/ZrO2-TiO2 calcined at different temperature had been studied. The effects of catalytic hydrolysis temperature and water vapor concentration on catalytic hydrolysis of CFC-12 were also studied. The results showed that catalytic hydrolysis rate of CFC-12 reached to 98.65 % at 400℃when the MoO3/ZrO2-TiO2 catalyst was calcined at 500℃ with a concentration of water vapor of 83.18%, and the main hydrolysis products were CO, CO2, HF and HCl. After 30 hours’ continuous reaction, the hydrolysis rate of CFC-12 was 65.34%. The XRD result reveals that the main phase of solid MoO3/ZrO2-TiO2 catalyst is the tetragonal Zr (MoO4)2with doped TiO2 of anatase.

2020 ◽  
Author(s):  
Zhiqian Li ◽  
Tong Zhou ◽  
Guoqing Ren ◽  
Xiaofang Tan ◽  
Lijuan Jia ◽  
...  

Abstract The catalytic hydrolysis of Difluorodichloromethane(CFC-12) by solid acid of MoO3/ZrO2-TiO2 calcined at different temperature had been studied. The effects of catalytic hydrolysis temperature and water vapor concentration on catalytic hydrolysis of CFC-12were also studied. The results showed that catalytic hydrolysis rate of CFC-12 reached to 98.65% at 400 ℃ when the MoO3/ZrO2-TiO2 catalyst was calcined at 500 ℃ with a concentration of water vapor of 83.18%, and the main hydrolysis products were CO, CO2, HF and HCl. After 30 hours’ continuous reaction, the hydrolysis rate of CFC-12 was 65.34%. The XRD result reveals that the main phase of solid MoO3/ZrO2-TiO2 catalyst is the tetragonal Zr (MoO4)2 with doped TiO2 of anatase.


2020 ◽  
Author(s):  
Zhiqian Li ◽  
Tong Zhou ◽  
Guoqing Ren ◽  
Xiaofang Tan ◽  
Lijuan Jia ◽  
...  

Abstract The catalytic hydrolysis of Difluorodichloromethane(CFC-12) by solid acid of MoO3/ZrO2-TiO2 calcined at different temperature had been studied. The effects of catalytic hydrolysis temperature and water vapor concentration on catalytic hydrolysis of CFC-12were also studied. The results showed that catalytic hydrolysis rate of CFC-12 reached to 98.65 % at 400。C when the MoO3/ZrO2-TiO2 catalyst was calcined at 500℃ with a concentration of water vapor of 83.18% ,and the main hydrolysis products were CO, CO2, HF and HCl. After 30 hours’ continuous reaction, the hydrolysis rate of CFC-12 was 65.34%. The XRD result reveals that the main phase of solid MoO3/ZrO2-TiO2 catalyst is the tetragonal Zr(MoO4)2with dopedTiO2 of anatase.


2020 ◽  
Author(s):  
Zhiqian Li ◽  
Tong Zhou ◽  
Guoqing Ren ◽  
Xiaofang Tan ◽  
Lijuan Jia ◽  
...  

Abstract The catalytic behaviors of solid acid of MoO3/ZrO2-TiO2 calcined at different temperature for the catalytic hydrolysis of Dichlorodifluoromethane have been studided. The effects of catalytic hydrolysis temperature and water vapor concentration on catalytic hydrolysis of Dichloro difluoromethane were also studied. The Results show 98.65 % of Dichlorodifluoromethane is degraded over MoO3/ZrO2-TiO2 catalyst calcined at 500 ℃ with a concentration of water vapor of 83.18% when the hydrolysis temperature is 350 ℃ and the Dichlorodifluoromethane flux rate is 1 mL/min with main degradation products were CO, CO2, HF and HCl. A maintained degradation rate of 65.34% of Difluoromethylene Chloride has been observed through 30 hours’ continuous reaction over the catalyst of MoO3/ZrO2-TiO2. The XRD result reveals the main phase of solid MoO3/ZrO2-TiO2 catalyst is the tetragonal Zr (MoO4)2 that dopedTiO2 of anatase.


2019 ◽  
Author(s):  
Zhiqian Li ◽  
Tong Zhou ◽  
Guoqing Ren ◽  
Xiaofang Tan ◽  
Lijuan Jia ◽  
...  

Abstract The catalytic behaviors of solid acid of MoO3/ZrO2-TiO2 calcined at different temperature for the catalytic hydrolysis of Dichlorodifluoromethane have been studided. The effects of catalytic hydrolysis temperature and water vapor concentration on catalytic hydrolysis of Dichlorodifluoromethane were also studied. The Results show 98.65 % of Dichlorodifluoromethane is degraded over MoO3/ZrO2-TiO2 catalyst calcined at 500 ℃ with a concentration of water vapor of 83.18% when the hydrolysis temperature is 400。C and the Dichlorodifluoromethane flux rate is 1mL/min with main degradation products were CO, CO2, HF and HCl. A maintained degradation rate of 65.34 % of Difluoromethylene Chloride has been observed through 30 hours’ continuous reaction over the catalyst of MoO3/ZrO2-TiO2. The XRD result reveals the main phase of solid MoO3/ZrO2-TiO2 catalyst is the tetragonal Zr(MoO4)2 that doped TiO2 of anatase.


2013 ◽  
Vol 726-731 ◽  
pp. 535-538
Author(s):  
Tian Cheng Liu ◽  
Yu Jiao Guo ◽  
Ping Ning ◽  
Guang Yang Tang ◽  
Ming Long Yuan

Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl2F2) in the presence of water vapor and oxygen was studied over solid acid MoO3/ZrO2 using a fixed-bed reactor. The CCl2F2 adsorption was multilayer chemical adsorption and its process was corresponding with Freundlich model. Its heat was from 56.3 to 73.2 KJ.mol-1, and it was exothermic reaction and chemical adsorption.


2013 ◽  
Vol 750-752 ◽  
pp. 1283-1286
Author(s):  
Tian Cheng Liu ◽  
Yu Jiao Guo ◽  
Ping Ning ◽  
Si Ping Ji ◽  
Bin Li ◽  
...  

Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl2F2) in the presence of water vapor and oxygen was studied over solid acid MoO3/ZrO2 using a fixed-bed reactor. The adsorption velocity equation was calculated by Bangham Equation. Reaction energy was determined by Arrhenius Equation and it was 123.12 KJ.mol-1.


Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 593
Author(s):  
Nasim Alikhani ◽  
Douglas W. Bousfield ◽  
Jinwu Wang ◽  
Ling Li ◽  
Mehdi Tajvidi

In this study, a simplified two-dimensional axisymmetric finite element analysis (FEA) model was developed, using COMSOL Multiphysics® software, to simulate the water vapor separation in a moisture-selective hollow-fiber membrane for the application of air dehumidification in wood drying processes. The membrane material was dense polydimethylsiloxane (PDMS). A single hollow fiber membrane was modelled. The mass and momentum transfer equations were simultaneously solved to compute the water vapor concentration profile in the single hollow fiber membrane. A water vapor removal experiment was conducted by using a lab-scale PDMS hollow fiber membrane module operated at constant temperature of 35 °C. Three operation parameters of air flow rate, vacuum pressure, and initial relative humidity (RH) were set at different levels. The final RH of dehydrated air was collected and converted to water vapor concentration to validate simulated results. The simulated results were fairly consistent with the experimental data. Both experimental and simulated results revealed that the water vapor removal efficiency of the membrane system was affected by air velocity and vacuum pressure. A high water vapor removal performance was achieved at a slow air velocity and high vacuum pressure. Subsequently, the correlation of Sherwood (Sh)–Reynolds (Re)–Schmidt (Sc) numbers of the PDMS membrane was established using the validated model, which is applicable at a constant temperature of 35 °C and vacuum pressure of 77.9 kPa. This study delivers an insight into the mass transport in the moisture-selective dense PDMS hollow fiber membrane-based air dehumidification process, with the aims of providing a useful reference to the scale-up design, process optimization and module development using hollow fiber membrane materials.


Author(s):  
S. H. Kim ◽  
K. B. Shim ◽  
C. S. Kim ◽  
J. T. Chou ◽  
T. Oshima ◽  
...  

The influence of water vapor in air on power generation characteristic of solid oxide fuel cells was analyzed by measuring cell voltage at a constant current density, as a function of water vapor concentration at 800°C and 1000°C. Cell voltage change was negligible at 1000°C, while considerable voltage drop was observed at 800°C accelerated at high water vapor concentrations of 20 wt % and 40 wt %. It is considered that La2O3 formed on the (La0.8Sr0.2)0.98MnO3 surface, which is assumed to be the reason for a large voltage drop.


2018 ◽  
Vol 36 (13) ◽  
pp. 2667-2674 ◽  
Author(s):  
Arun Kumar Mallik ◽  
Gerald Farrell ◽  
Dejun Liu ◽  
Vishnu Kavungal ◽  
Qiang Wu ◽  
...  

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