Conversion of Glycerol into Value-Added Products Over Cu–Ni Catalyst Supported on γ-Al2O3 and Activated Carbon

2014 ◽  
Vol 12 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Satyanarayana Murty Pudi ◽  
Tarak Mondal ◽  
Prakash Biswas ◽  
Shalini Biswas ◽  
Shishir Sinha

Abstract A series of Cu, Ni monometallic and bimetallic catalysts supported on γ-Al2O3 and activated carbon were synthesized by incipient wetness impregnation method and examined for hydrogenolysis and esterification of glycerol. Hydrogenolysis reaction was carried out in a 250 ml Teflon-coated stainless steel batch reactor at 250°C and 10 bar H2 pressure, whereas esterification of glycerol with acetic acid was carried out at 120°C at atmospheric pressure. The physiochemical properties of the catalysts were investigated by various techniques such as surface area, X-ray diffraction (XRD), NH3-temperature-programmed desorption (TPD). Characterization results dictated that the reduction behavior, acidic nature and the metal support interactions were varied with the support as well as Cu/Ni weight ratio. The XRD results confirmed the formation of mixed oxide Cu0.75Ni0.25 Al2O4 phase in Cu–Ni (3:1)/γ-Al2O3 catalyst. Among the catalysts tested, Cu–Ni bimetallic catalysts showed superior performance as compared to monometallic catalysts in both the reactions. The glycerol hydrogenolysis activity of γ-Al2O3 supported Cu–Ni catalysts was higher than the activated carbon-supported catalysts. 1,2-PDO was obtained as the main hydrogenolysis product independent of the support as well as Cu/Ni weight ratio and its selectivity was in the range of 92.8–98.5%. The acidic nature of γ-Al2O3 and the mixed oxide (Cu0.75Ni0.25Al2O4) phase played an important role for hydrogenolysis activity. Cu–Ni (3:1)/γ-Al2O3 catalyst showed the maximum 1,2-PDO selectivity to 97% with 27% glycerol conversion after a reaction time of 5 h. On the other hand, Cu–Ni(1:3)/C catalyst showed the highest glycerol conversion of 97.4% for esterification and obtained selectivity to monoacetin, diacetin and triacetin were 26.1%, 67.2% and 6.5%, respectively.

2017 ◽  
Vol 61 (4) ◽  
pp. 295
Author(s):  
Tamer S. Ahmed ◽  
Omar Y. Abdelaziz ◽  
George W. Roberts

In recent years, much attention has been focused on the hydrogenolysis of biodiesel derived glycerol to other high value products for the sustainable development and efficient valorization strategies. In the present work, alumina-supported Ir catalyst was prepared by the incipient wetness impregnation method and tested in the glycerol hydrogenolysis reaction. The synthesized catalyst was characterized by neutron activation analysis, N2 physisorption, and H2 chemisorption techniques. The experiments standard conditions were 150 mL feed volume, 0.3 g catalyst, 1500 rpm stirring speed, and 5 wt% glycerol aqueous solution for 4 h. The effects of catalyst amount, temperature, hydrogen pressure, stirring speed, and solution pH on glycerol conversion and selectivity of the principal products obtained were also investigated. The glycerol conversion and the 1,2-propanediol selectivity varied from 4.9% to 22% and from 23.8% to 70.3%, respectively. It was found that the selectivity of 1,2-propanediol increased significantly with the increased alkalinity of the reaction medium.


2016 ◽  
Vol 6 (12) ◽  
pp. 4327-4336 ◽  
Author(s):  
Y. Kathiraser ◽  
J. Ashok ◽  
S. Kawi

Highly dispersed Ni–Fe bimetallic catalysts supported on mesoporous SBA-15 were synthesized via an incipient wetness impregnation method by impregnation of a small amount of oleic acid mixed with a metal precursor on the SBA-15 support.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1426
Author(s):  
Marwa Saad ◽  
Agnieszka Szymaszek ◽  
Anna Białas ◽  
Bogdan Samojeden ◽  
Monika Motak

A series of materials based on activated carbon (AC) with copper deposited in various amounts were prepared using an incipient wetness impregnation method and tested as catalysts for selective catalytic reduction of nitrogen oxides with ammonia. The samples were poisoned with SO2 and regenerated in order to analyze their susceptibility to deactivation by the harmful component of exhaust gas. NO conversion over the fresh catalyst doped with 10 wt.% of Cu reached 81% of NO conversion at 140 °C and about 90% in the temperature range of 260–300 °C. The rate of poisoning with SO2 was dependent on Cu loading, but in general, it lowered NO conversion due to the formation of (NH4)2SO4 deposits that blocked the active sites of the catalysts. After regeneration, the catalytic activity of the materials was restored and NO conversion exceeded 70% for all of the samples.


2019 ◽  
Vol 45 ◽  
pp. 146867831987032
Author(s):  
Zhang Jiaying

A series of Ni–Fe/MCM-41 bimetallic catalysts and also Ni/MCM-41 and Fe/MCM-41 catalysts were prepared by the incipient-wetness impregnation method and tested for their activity for CO methanation in a continuous-flow microreactor. The results showed that the catalytic activities of the Ni–Fe/MCM-41 bimetallic catalysts were much higher than those of the Ni/MCM-41 and Fe/MCM-41 catalysts at low temperatures (200°C–325°C). The 10%Ni–5%Fe/MCM-41 catalyst showed the best activity with a CO conversion of almost 100% and a CH4 selectivity of 98% at 350°C under a pressure of 1.5 MPa with a 3:1 molar ratio of H2 to CO and a weight hourly space velocity of 12,000 mL h−1 g−1. The catalysts were characterized by N2 physisorption measurements, X-ray diffraction, and H2-temperature-programmed reduction. The results showed that the addition of Fe will lead to the formation of finer Ni particles and Ni–Fe alloy, which were the main reasons for the activity increase in the Ni–Fe/MCM-41 catalysts.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1354
Author(s):  
Mahlet N. Gebresillase ◽  
Reibelle Q. Raguindin ◽  
Hern Kim ◽  
Jeong Gil Seo

γ-valerolactone (GVL) is an important value-added chemical with potential applications as a fuel additive, a precursor for valuable chemicals, and polymer synthesis. Herein, different monometallic and bimetallic catalysts supported on γ-Al2O3 nanofibers (Ni, Cu, Co, Ni-Cu, Ni-Co, Cu-Co) were prepared by the incipient wetness impregnation method and employed in the solvent-free hydrogenation of levulinic acid (LA) to GVL. The influence of metal loading, metal combination, and ratio on the activity and selectivity of the catalysts was investigated. XRD, SEM-EDS, TEM, H2-TPR, XPS, NH3-TPD, and N2 adsorption were used to examine the structure and properties of the catalysts. In this study, GVL synthesis involves the single-step dehydration of LA to an intermediate, followed by hydrogenation of the intermediate to GVL. Ni-based catalysts were found to be highly active for the reaction. [2:1] Ni-Cu/Al2O3 catalyst showed 100.0% conversion of LA with >99.0% selectivity to GVL, whereas [2:1] Ni-Co/Al2O3 yielded 100.0% conversion of LA with 83.0% selectivity to GVL. Moreover, reaction parameters such as temperature, H2 pressure, time, and catalyst loading were optimized to obtain the maximum GVL yield. The solvent-free hydrogenation process described in this study propels the future industrial production of GVL from LA.


2015 ◽  
Vol 77 (33) ◽  
Author(s):  
Azizul Hakim ◽  
Maratun Najiha Abu Tahari ◽  
Tengku Sharifah Marliza ◽  
Wan Nor Roslam Wan Isahak ◽  
Muhammad Rahimi Yusop ◽  
...  

Anthropogenic gas of CO2 level was higher than CO2 atmospheric safety limit of 350 ppm since 80’s. It can be assumed that CO2 level growth directly proportional to the population and development. Hence, studies on CO2 capture have been extensively established in between year of 2000-2010. Metal oxide can be a good adsorbent but it has the weakness in surface area and sintered after regeneration process. Thus, activated carbon was used to enhance the surface area which mainly responsible for physical adsorption. Fe2O3 supported on activated carbon (Fe2O3/AC) were prepared by impregnation method and used for CO2 adsorption-desorption studies. The XRD result shows that precursor of ferric nitrate used to impregnated on AC (activated carbon) support was directly dissociated to Fe2O3 metal oxide by thermal treatment under N2 atmosphere temperature at 450 °C. The loading amount of Fe2O3 by weight ratio affect the textural properties and CO2 capturing capacity. The surface area and pore volume of the catalyst decrease with the loading of Fe2O3. Highest Fe2O3 loading shows greater amount chemically adsorbed of CO2. Nevertheless, it drastically reduced the surface area of the AC, which is chiefly responsible for CO2 physisorption, thus decreasing the carrying capacity of ACs at 25 °C. The 20Fe2O3/AC was found to be optimum loading for better physi and chemisorptions of CO2.


2020 ◽  
Vol 5 (3) ◽  
pp. 221
Author(s):  
Muhammad Azam ◽  
Muhammad Anas ◽  
Erniwati Erniwati

This study aims to determine the effect of variation of activation temperature of activated carbon from sugar palm bunches of chemically activatied with the activation agent of potassium silicate (K2SiO3) on the adsorption capacity of iodine and methylene blue. Activated carbon from bunches of sugar palmacquired in four steps: preparationsteps, carbonizationstepsusing the pyrolysis reactor with temperature of 300 oC - 400 oC for 8 hours and chemical activation using of potassium silicate (K2SiO3) activator in weight ratio of 2: 1 and physical activation using the electric furnace for 30 minutes with temperature variation of600 oC, 650 oC, 700 oC, 750 oC and 800 oC. The iodine and methyleneblue adsorption testedby Titrimetric method and Spectrophotometry methodrespectively. The results of the adsorption of iodine and methylene blue activated carbon from sugar palm bunches increased from 240.55 mg/g and 63.14 mg/g at a temperature of 600 oC to achieve the highest adsorption capacity of 325.80 mg/g and 73.59 mg/g at temperature of 700 oC and decreased by 257.54 mg/g and 52.03 mg/g at a temperature of 800 oCrespectively.However, it does not meet to Indonesia standard (Standard Nasional Indonesia/SNI), which is 750 mg/g and 120 mg/g respectively.


2020 ◽  
Vol 10 (6) ◽  
pp. 849-859
Author(s):  
Radwa A. El-Salamony ◽  
Abeer A. Emam ◽  
Nagwa A. Badawy ◽  
Sara F. El-Morsi

Objective: ZnO nanoparticles were synthesized using wet impregnation method, and activated carbon from rice straw (RS) prepared through chemical route. Methods: The nano-composites ZnO-AC series were prepared with different ZnO:AC ratio of 10, 20, 50, and 70% to optimize the zinc oxide nanoparticles used. The obtained composites were characterized by FE-SEM, XRD, SBET, and optical techniques then used for the photo-degradation of Malachite green dye (MG) under visible light. Results: It was found that 10ZnO-AC exhibited excellent visible light photo-catalytic performance. The ·OH radicals’ formation is matching with photo-activity of the prepared composites. The photo-degradation efficiency of MG increased from 63% to 93%, when the 10ZnO-AC photocatalyst amount was increased from 0.5 to 6 g/L. Conclusion: The GC-MS technique was used to analyze the intermediates formed; up to 15 kinds of chemicals were identified as the degradation products.


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.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 553
Author(s):  
Mansurbek Urol ugli Abdullaev ◽  
Sungjune Lee ◽  
Tae-Wan Kim ◽  
Chul-Ung Kim

Among the zeolitic catalysts for the ethylene-to-propylene (ETP) reaction, the SSZ-13 zeolite shows the highest catalytic activity based on both its suitable pore architecture and tunable acidity. In this study, in order to improve the propylene selectivity further, the surface of the SSZ-13 zeolite was modified with various amounts of tungsten oxide ranging from 1 wt% to 15 wt% via a simple incipient wetness impregnation method. The prepared catalysts were characterized with several analysis techniques, specifically, powder X-ray diffraction (PXRD), Raman spectroscopy, temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and N2 sorption, and their catalytic activities were investigated in a fixed-bed reactor system. The tungsten oxide-modified SSZ-13 catalysts demonstrated significantly improved propylene selectivity and yield compared to the parent H-SSZ-13 catalyst. For the tungsten oxide loading, 10 wt% loading showed the highest propylene yield of 64.9 wt%, which was 6.5 wt% higher than the pristine H-SSZ-13 catalyst. This can be related to not only the milder and decreased strong acid sites but also the diffusion restriction of bulky byproducts, as supported by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) observation.


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