Hydrogen Cyanide Removal over Ti-Al2O3 Catalyst: Activity at Low Temperature

2019 ◽  
Vol 36 (9) ◽  
pp. 1011-1018
Author(s):  
Fei Wang ◽  
You Lv ◽  
Wang Xueqian ◽  
Yixing Ma ◽  
Ping Ning
Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.


2013 ◽  
Vol 25 (4) ◽  
pp. 808-814 ◽  
Author(s):  
Ping Ning ◽  
Juan Qiu ◽  
Xueqian Wang ◽  
Wei Liu ◽  
Wei Chen

2017 ◽  
Vol 3 (3) ◽  
pp. 157
Author(s):  
M. Furutani ◽  
Y. Ohta ◽  
M. Nose

<p>Flat low-temperature two-stage flames were established on a Powling burner using rich diethyl-ether/ air or n-heptane/air mixtures, and nitrogen monoxide NO was added into the fuel-air mixtures with a concentration of 240 ppm. The temperature development and chemical-species histories, especially of NO, nitrogen dioxide NO<sub>2</sub> and hydrogen cyanide HCN were examined associated with an emission-spectrum measurement from the low-temperature flames. Nitrogen monoxide was consumed in the cool-flame region, where NO was converted to the NO<sub>2</sub>. The NO<sub>2</sub> generated, however, fell suddenly in the cool-flame degenerate region, in which the HCN superseded. In the blue-flame region the NO came out again and developed accompanied with remained HCN in the post blue-flame region. The NO seeding into the mixture intensified the blue-flame luminescence probably due to the cyanide increase.</p>


2011 ◽  
Vol 141 (12) ◽  
pp. 1723-1731 ◽  
Author(s):  
Linda Z. Linganiso ◽  
Venkat Ramana Rao Pendyala ◽  
Gary Jacobs ◽  
Burtron H. Davis ◽  
Donald C. Cronauer ◽  
...  

1968 ◽  
Vol 14 (11) ◽  
pp. 1169-1172 ◽  
Author(s):  
Awatar S. Sekhon ◽  
Nicholas Colotelo

Changes in dry weight, hydrogen cyanide production, peroxidase, and soluble proteins of mycelium of a low-temperature basidiomycete with age of cultures were studied.Hydrogen cyanide was detected only after there was a decrease in growth of mycelium as determined by dry-weight measurements. Polyacrylamide gel electrophoretic analyses showed that the pattern and numbers of peroxidase and other soluble-protein bands varied with the age of the culture. Concomitant with decreases in yield of mycelium, there was a decrease in the numbers of peroxidase and soluble-protein bands.


Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 136
Author(s):  
Ourmazd Dehghani ◽  
Mohammad Rahimpour ◽  
Alireza Shariati

The current research presents an experimental approach on the mechanism, kinetic and decay of industrial Pd-Ag supported α-Al2O3 catalyst used in the acetylene hydrogenation process. In the first step, the fresh and deactivated hydrogenation catalysts are characterized by XRD, BET (Brunauer–Emmett–Teller), SEM, TEM, and DTG analyses. The XRD results show that the dispersed palladium particles on the support surface experience an agglomeration during the reaction run time and mean particle size approaches from 6.2 nm to 11.5 nm. In the second step, the performance of Pd-Ag supported α-Al2O3 catalyst is investigated in a differential reactor in a wide range of hydrogen to acetylene ratio, temperature, gas hourly space velocity and pressure. The full factorial design method is used to determine the experiments. Based on the experimental results ethylene, ethane, butene, and 1,3-butadiene are produced through the acetylene hydrogenation. In the third step, a detailed reaction network is proposed based on the measured compounds in the product and the corresponding kinetic model is developed, based on the Langmuir-Hinshelwood-Hougen-Watson approach. The coefficients of the proposed kinetic model are calculated based on experimental data. Finally, based on the developed kinetic model and plant data, a decay model is proposed to predict catalyst activity and the parameters of the activity model are calculated. The results show that the coke build-up and condensation of heavy compounds on the surface cause catalyst deactivation at low temperature.


2020 ◽  
Vol 61 (2) ◽  
pp. 304-309
Author(s):  
H. Su ◽  
Y. Zheng ◽  
X. Sun ◽  
L. Sun ◽  
X. F. Xu ◽  
...  

2015 ◽  
Vol 135 ◽  
pp. 66-72 ◽  
Author(s):  
Fan Cao ◽  
Jun Xiang ◽  
Sheng Su ◽  
Pengying Wang ◽  
Song Hu ◽  
...  

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