Effect of catalyst composition and reaction conditions on synthesis of phenyl isocyanate by carbonylation of nitrobenzene

Author(s):  
V. I. Manov-Yuvenskii ◽  
B. K. Nefedov ◽  
A. V. Smetanin
Fuel ◽  
2008 ◽  
Vol 87 (17-18) ◽  
pp. 3483-3489 ◽  
Author(s):  
Nianjun Luo ◽  
Xianwen Fu ◽  
Fahai Cao ◽  
Tiancun Xiao ◽  
Peter P. Edwards

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1307 ◽  
Author(s):  
No-Kuk Park ◽  
Young Lee ◽  
Byung Kwon ◽  
Tae Lee ◽  
Suk Kang ◽  
...  

In this study, nickel-based reforming catalysts were synthesized for the reforming of toluene, a major component of thinners and widely used as an organic solvent. The reaction characteristics of these catalysts were investigated by both steam reforming and auto-thermal reforming. Reforming aromatic hydrocarbons like toluene to produce synthesis gas is difficult because carbon deposition also occurs, and the deposition of carbon lowers the activity of the catalyst and causes a pressure drop during the reaction process. In order to maintain a stable reforming process, a catalytic reaction technique capable of suppressing carbon deposition is required. Steam reforming and auto-thermal reforming of toluene were used in this study, and the temperature of the catalyst bed was remarkably reduced, due to a strong endothermic reaction during the reforming process. By using scanning electric microscopy (SEM), X-ray diffraction (XRD), and temperature-programmed oxidation analysis, it is shown that carbon deposition was markedly generated due to a catalyst bed temperature decrease. In this study, optimum conditions for catalyst composition and the reforming reaction are proposed to suppress the formation of carbon on the catalyst surface, and to remove the generated carbon from the process. In addition, ceria and zirconia were added as catalytic promoters to inhibit carbon deposition on the catalyst surface, and the carbon deposition phenomena according to the catalyst’s promoter content were investigated. The results showed that the carbon deposition inhibition function of CeO2, via its redox properties, is insignificant in steam reforming, but is notably effective in the auto-thermal reforming of toluene.


2012 ◽  
Vol 84 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Andrea Vavasori ◽  
Lucio Ronchin

1,3-Diphenylurea (DPU) has been proposed as a synthetic intermediate for phosgene-free synthesis of methyl N-phenylcarbamate and phenyl isocyanate, which are easily obtained from the urea by reaction with methanol. Such an alternative route to synthesis of carbamates and isocyanates necessitates an improved phosgene-free synthesis of the corresponding urea. In this work, it is reported that Pd(II)-diphosphine catalyzed reductive carbonylation of nitrobenzene in acetic acid (AcOH)-methanol proceeds in high yield and selectivity as a one-step synthesis of DPU. We have found that the catalytic activity and selectivity of this process depends on solvent composition and on the bite angle of the diphosphine ligands. Under optimum reaction conditions, yields in excess of 90 molar % and near-quantitative selectivity can be achieved.


2012 ◽  
Vol 610-613 ◽  
pp. 376-380
Author(s):  
Ruo Kun Jia ◽  
Chao Yang ◽  
Song Zhu Lin

Methyl orange stimulated wastewater was treated using non-homogeneous Fenton reaction. First the effect of catalyst composition on the treatment was investigated and then further investigation of the impact of reaction conditions on the degradation effect in the catalytic process was carried out. It showed the optimal conditions of treating methyl orange wastewater(100ml) of 10mg/L, The optimal conditions for catalyst preparation through experiments above were: proportion of the elements in the catalyst was Co0.5Fel.0(MgO)2.5, this article examined the impact of reaction conditions on the catalytic properties of the catalytic process. It turned out that on the condition that the amount of catalyst was 0.9g/L hydrogen peroxide concentration was 2.5ml/L, within the scope of application in a wide pH (4~14), catalyst degradation efficiency was significantly superior to conventional homogeneous Fenton system and methyl orange removal efficiency was above 95%.


2007 ◽  
Vol 554 ◽  
pp. 37-42 ◽  
Author(s):  
M. Hasni ◽  
J. Rouchaud ◽  
P. Grange ◽  
M. Devillers ◽  
S. Delsarte

Nitridation of amorphous aluminium phosphate (AlPO4) and mixed aluminium gallium phosphate (Al0.5Ga0.5PO4) under ammonia flow allows preparing “AlPON” and “AlGaPON” bifunctional acid-base heterogeneous catalysts. Their acid-base bi-functional character allows their use as selective catalysts for the production of jasminaldehyde through the cross-condensation of heptanal and benzaldehyde, followed by the dehydration of the aldol intermediate product. Three parameters enabling to maximize the jasminaldehyde yields in a batch reactor operated at 125°C were investigated: the catalyst composition (Al/Ga and O/N ratio), the reactant concentration and the amount of catalyst in the reactor. Maximum jasminaldehyde selectivities were obtained for intermediate nitrogen contents (7-10 wt.%). Maximum reaction rates were obtained using pure reactants and a catalysts weight equal to 10% of the total reagent weight.


2007 ◽  
Vol 319 ◽  
pp. 98-110 ◽  
Author(s):  
Evgenii V. Kondratenko ◽  
Olga Ovsitser ◽  
Joerg Radnik ◽  
Matthias Schneider ◽  
Ralph Kraehnert ◽  
...  

1994 ◽  
Vol 5 (1-2) ◽  
pp. 103-115 ◽  
Author(s):  
Ki Dong Kim ◽  
In-Sik Nam ◽  
Jong Shik Chung ◽  
Jae Sung Lee ◽  
Sam Gon Ryu ◽  
...  

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