Synthetic Technics of Methyl Acrylate through Aldol Condensation with a Multisubsection Fixed-Bed Reactor

2011 ◽  
Vol 233-235 ◽  
pp. 2859-2862 ◽  
Author(s):  
Tao Jing ◽  
Jing Zhi Tian ◽  
De Zhi Sun

Two types of catalysts, V2O5-P2O5/SiO2and Cs-Sb2O5/SiO2, were separately prepared with SiO2as carrier. Their catalytic properties were investigated in the process of synthesizing methyl acrylate through aldol condensation with methylal and methyl acetate, and the influence of the catalyst’s filling up technique on the reaction was studied. Reactions were performed in a fixed-bed reactor. The research results indicate that aldol condensation reaction is effectively promoted when the two catalysts were filled up in appropriate subsections of the reaction tube. Specifically, when V-Si-P Oxide was filled up at the 4thsubsection and Cs-Sb2O5/SiO2catalyst at the 6thsubsection with the temperature of the reactor at 400 °C and the mol ratio of methyl acetate and methylal at 1.6:1 and the space velocity at 3.2 h-1, then the conversion rate of methylal was 50.9%, the selectivity of methyl acrylate was 90.63%, and the ester yield of methyl acrylate was 46.15%.

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1068
Author(s):  
Zdeněk Tišler ◽  
Pavla Vondrová ◽  
Kateřina Hrachovcová ◽  
Kamil Štěpánek ◽  
Romana Velvarská ◽  
...  

Aldol condensation reaction is usually catalysed using homogeneous catalysts. However, the heterogeneous catalysis offers interesting advantages and the possibility of cleaner biofuels production. Nowadays, one of the most used kinds of heterogeneous catalysts are hydrotalcites, which belong to a group of layered double hydroxides. This paper describes the aldol condensation of cyclohexanone (CH) and furfural (F) using Mg/Al mixed oxides and rehydrated mixed oxides in order to compare the catalyst activity after calcination and rehydration, as well as the possibility of its regeneration. The catalysts were synthesized by calcination and subsequent rehydration of the laboratory-prepared and commercial hydrotalcites, with Mg:Al molar ratio of 3:1. Their structural and chemical properties were determined by several analytical methods (inductively coupled plasma analysis (ICP), X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), specific surface area (BET), thermogravimetric analysis (TGA), temperature programmed desorption (TPD)). F-CH aldol condensation was performed in a continuous fixed-bed reactor at 80 °C, CH:F = 5:1, WHSV 2 h−1. The rehydrated laboratory-prepared catalysts showed a 100% furfural conversion for more than 55 h, in contrast to the calcined ones (only 24 h). The yield of condensation products FCH and F2CH was up to 68% and 10%, respectively. Obtained results suggest that Mg/Al mixed oxides-based heterogeneous catalyst is suitable for use in the aldol condensation reaction of furfural and cyclohexanone in a fixed-bed reactor, which is an interesting alternative way to obtain biofuels from renewable sources.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3684
Author(s):  
Sukhe Badmaev ◽  
Vladimir Sobyanin

The catalytic properties of CuO-CeO2 supported on alumina for the oxidative steam reforming (OSR) of dimethoxymethane (DMM) to hydrogen-rich gas in a tubular fixed bed reactor were studied. The CuO-CeO2/γ-Al2O3 catalyst provided complete DMM conversion and hydrogen productivity > 10 L h−1 gcat−1 at 280 °C, GHSV (gas hourly space velocity) = 15,000 h−1 and DMM:O2:H2O:N2 = 10:2.5:40:47.5 vol.%. Comparative studies showed that DMM OSR exceeded DMM steam reforming (SR) and DMM partial oxidation (PO) in terms of hydrogen productivity. Thus, the outcomes of lab-scale catalytic experiments show high promise of DMM oxidative steam reforming to produce hydrogen-rich gas for fuel cell feeding.


2013 ◽  
Vol 781-784 ◽  
pp. 308-311 ◽  
Author(s):  
Xin Li ◽  
Wei Su ◽  
Qi Bin Xia ◽  
Zhi Meng Liu

Manganese and cerium based catalysts with different Mn/Ce molar ratios prepared by impregnation method for ethyl acetate oxidation. The activity tests of the samples were performed in a fixed-bed reactor. The effect of gas hourly space velocity (GHSV) and ethyl acetate concentration on the catalytic activity of the catalyst were also investigated. The results showed that these catalysts had high activity for the catalytic oxidation of ethyl acetate, of which the catalyst Mn0.9Ce0.1Ox/TiO2exhibitedthe bestactivity, and the temperature required for 90% conversion of ethyl acetate was at 216 °C. The catalyst Mn0.9Ce0.1Ox/TiO2still maintained high activity in the range of GHSV (16,500 to 48,500 h-1) and ethyl acetate concentration (4526 to 7092 mg/m3). In additional, experiments for measuring stability of Mn0.9Ce0.1Ox/TiO2were carried out, and experimental results showed that the good stability of Mn0.9Ce0.1Ox/TiO2was kept after it has run for 25 hours.


2012 ◽  
Vol 161 ◽  
pp. 194-199
Author(s):  
Yue Juan Duan ◽  
Hua Wang ◽  
Yong Gang Wei ◽  
Kong Zhai Li ◽  
Xing Zhu ◽  
...  

Pure CeO2and a series of (x %) K-CeO2(x=1, 2, 3, 4) catalysts were respectively prepared by the precipitation and incipient wetness impregnation methods, and characterized by means of XRD, BET and H2-TPR techniques. The catalytic activity was investigated by the gas-solid reaction with methane in the absence of gaseous oxidant in a fixed bed reactor at 800 °C. The XRD measurement showed that doping of K2CO3did not change the structure of CeO2with the addition of K2CO3 without formation of Ce-K-O solid solution in these materials. Surface area of catalysts wasSubscript textdecreased with the impregnation amount of K2CO3. Reducibility of catalysts was obviously enhanced by the addition of K2CO3as shown in H2-TPR tests. The catalysts activity tests indicated that adding K2CO3to CeO2could promote the oxygen storage capacity of catalysts. K species in CeO2could affect the CO formation in methane oxidation.


RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 16727-16734 ◽  
Author(s):  
Jigang Zhao ◽  
Junjian Zeng ◽  
Xiaoguang Cheng ◽  
Lei Wang ◽  
Henghua Yang ◽  
...  

The bimetal catalyst gold(iii) chloride–copper(ii) chloride (AuCl3–CuCl2) was prepared with different gamma-aluminium oxide (γ-Al2O3) supports and its catalytic properties towards acetylene hydrochlorination were assessed in a fixed-bed reactor.


2011 ◽  
Vol 396-398 ◽  
pp. 764-767
Author(s):  
Tai Xuan Jia ◽  
Ji Chang Zhang ◽  
Zi Li Liu

Y-Mg-Al-layered double Oxides (Y-Mg-Al-LDO) were prepared by calcining Y3+-doped Mg-Al-layered hydrotalcites at 823 K for 8 h from co-precipitation method. The samples were detected by XRD and CO2-TPD. Micro-structure and essential regularity were disclosed. The acetone condensation reaction as a probe reaction was carried on fixed-bed micro-reactor at reactive temperature 673 K, reactive time 3 h and liquid hourly space velocity (LHSV) 6 h-1 over Y-Mg-Al-LDO. The catalyst evaluation results show that Y-Mg-Al-LDO possess high catalytic activity. The maximum value of acetone conversion reached 37.53%. The selectivity and single-pass-yield of isophorone were 55.66% and 20.89%, respectively.


2020 ◽  
Vol 8 (1) ◽  
pp. 21-27
Author(s):  
Melia Laniwati Gunawan ◽  
IGBN Makertihartha ◽  
Subagjo Subagjo

Fatty alcohol (FAOH) can be produced by hydrogenating of fatty acid methyl ester (FAME) using the copper-based catalyst. Copper-Chrom (Cu-Cr) is the best catalyst for high-pressure reaction condition, which is copper (Cu) as the main active component and chrom (Cr) as a promoter. Since Cr is feared to be toxic, one of the best replacement candidates is manganese (Mn). The research aims is to find the kinetic equation of hydrogenation FAME to FAOH using a Cu-Mn commercial catalyst.  FAME with methyl laurate and methyl myristate as the main compounds is used as feedstock. The main products are lauryl alcohol and myristyl alcohol. The reaction was carried out in an isothermal continuous fixed bed reactor under conditions of temperature 220 – 240 oC, pressure 50 bar, and liquid hourly space velocity (LHSV) 5-12.5 hr-1.  The kinetic equation is determined using the power law model. The FAME hydrogenation on copper - manganese catalyst is the half order reaction. The activation energy value is 86.32 kJ/mol and the Arrhenius constant value is 5.87x106  M0.5/s.


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