scholarly journals Dehydration of Bioethanol to Ethylene over H-ZSM-5 Catalysts: A Scale-Up Study

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 186 ◽  
Author(s):  
Sanggil Moon ◽  
Ho-Jeong Chae ◽  
Min Park
Keyword(s):  
Reaction Temperature ◽  
Scale Up ◽  
Space Velocity ◽  
Ethanol Conversion ◽  
Bench Scale ◽  
Weight Hourly Space Velocity ◽  
Organic Solid ◽  
Ethylene Selectivity ◽  
High Ethanol ◽  
Scale Reactor

Bioethanol dehydration was carried out in a bench scale reactor-loaded H-ZSM-5 molded catalyst, which increased by tens of times more than at lab scale (up to 60 and 24 times based on the amount of catalyst and ethanol flow rate, respectively). From the results of the lab scale reaction, we confirmed the optimum Si/Al ratio (14) of H-ZSM-5, reaction temperature (~250 °C), and weight hourly space velocity (WHSV) (<5 h−1) indicating high ethanol conversion and ethylene selectivity. Five types of cylindrical shaped molded catalysts were prepared by changing the type and/or amount of organic solid binder, inorganic solid binder, inorganic liquid binder, and H-ZSM-5 basis catalyst. Among them, the catalyst exhibiting the highest compression strength and good ethanol dehydration performance was selected. The bench scale reaction with varying reaction temperature of 245–260 °C and 1.2– 2.0 h−1 WHSV according to reaction time showed that the conversion and ethylene selectivity were more than 90% after 400 h on stream. It was also confirmed that even after the successive catalyst regeneration and the reaction for another 400 h, both the ethanol conversion and ethylene selectivity were still maintained at about 90%.

Bench-Scale Steam Reforming of Methane for Hydrogen Production

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 615 ◽  
Author(s):  
Hae-Gu Park ◽  
Sang-Young Han ◽  
Ki-Won Jun ◽  
Yesol Woo ◽  
Myung-June Park ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Reaction Temperature ◽  
Steam Reforming ◽  
Methane Conversion ◽  
Large Scale ◽  
Production Capacity ◽  
Space Velocity ◽  
Bench Scale ◽  
Steam Reforming Of Methane ◽  
Scale Reactor

The effects of reaction parameters, including reaction temperature and space velocity, on hydrogen production via steam reforming of methane (SRM) were investigated using lab- and bench-scale reactors to identify critical factors for the design of large-scale processes. Based on thermodynamic and kinetic data obtained using the lab-scale reactor, a series of SRM reactions were performed using a pelletized catalyst in the bench-scale reactor with a hydrogen production capacity of 10 L/min. Various temperature profiles were tested for the bench-scale reactor, which was surrounded by three successive cylindrical furnaces to simulate the actual SRM conditions. The temperature at the reactor bottom was crucial for determining the methane conversion and hydrogen production rates when a sufficiently high reaction temperature was maintained (>800 °C) to reach thermodynamic equilibrium at the gas-hourly space velocity of 2.0 L CH4/(h·gcat). However, if the temperature of one or more of the furnaces decreased below 700 °C, the reaction was not equilibrated at the given space velocity. The effectiveness factor (0.143) of the pelletized catalyst was calculated based on the deviation of methane conversion between the lab- and bench-scale reactions at various space velocities. Finally, an idling procedure was proposed so that catalytic activity was not affected by discontinuous operation.

Hydrogen Production by Bio-Fuel Steam Reforming at Low Reaction Temperature

2011 ◽  
Author(s):  
Tsuyoshi Maeda ◽  
Toshio Shinoki ◽  
Jiro Funaki ◽  
Katsuya Hirata
Keyword(s):  
Reaction Temperature ◽  
Steam Reforming ◽  
High Performance ◽  
Space Velocity ◽  
Ethanol Conversion ◽  
Ethanol Steam Reforming ◽  
High Hydrogen ◽  
Low Reaction Temperature ◽  
Al2o3 Catalyst ◽  
Ethanol Steam

The authors reveal the dominant chemical reactions and the optimum conditions, supposing the design of ethanol steam-reforming reactors. Specifically speaking, experiments are conducted for Cu/ZnO/Al2O3 catalyst, together with those for Ru/Al2O3 catalyst for reference. Using a household-use-scale reactor with well-controlled temperature distributions, the authors compare experimental results with chemical-equilibrium theories. It has revealed by Shinoki et al. (2011) that the Cu/ZnO/Al2O3 catalyst shows rather high performance with high hydrogen concentration CH2 at low values of reaction temperature TR. Because, the Cu/ZnO/Al2O3 catalyst promotes the ethanol-steam-reforming and water-gas-shift reactions, but does not promote the methanation reaction. So, in the present study, the authors reveal that the Ru/Al2O3 catalyst needs high TR > 770 K for better performance than the Cu/ZnO/Al2O3 catalyst, and that the Ru/Al2O3 catalyst shows lower performance at TR < 770 K. Then, the Ru/Al2O3 catalyst is considered to activate all the three reactions even at low TR. Furthermore, concerning the Cu/ZnO/Al2O3 catalyst, the authors reveal the influences of liquid-hourly space velocity LHSV upon concentrations such as CH2, CCO2, CCO and CCH4 and the influence of LHSV upon the ethanol conversion XC2H5OH, in a range of LHSV from 0.05 h−1 to 0.8 h−1, at S/C = 3.0 and TR = 520 K. And, the authors reveal the influences of the thermal profile upon CH2, CCO2, CCO, CCH4 and XC2H5OH, for several LHSV’s. To conclude, with well-controlled temperatures, the reformed gas can be close to the theory. In addition, the authors investigate the influences of S/C.

Effect of the Calcination Temperature on Ni2P/TiO2-Al2O3 Catalyst Structure and Catalytic Activity for Hydrodesulfurization

2014 ◽  
Vol 1025-1026 ◽  
pp. 419-422
Author(s):  
Feng Li ◽  
Zai Shun Jin ◽  
Hua Lin Song ◽  
Yong Sheng Li ◽  
Jian Zhong Xu
Keyword(s):  
Catalytic Activity ◽  
Calcination Temperature ◽  
Reaction Temperature ◽  
Space Velocity ◽  
Nickel Phosphide ◽  
Catalyst Structure ◽  
Weight Hourly Space Velocity

Nickel phosphide Ni2P catalysts supported on TiO2-Al2O3support were prepared by co-impregnation. The catalysts were characterized by XRD, BET, and XPS. The effects of calcination temperature on catalyst structure and HDS activity were studied. The results indicated that the catalyst prepared with calcination temperature of 773 K exhibited the best performance. At a reaction temperature of 606 K, a pressure of 3.0 MPa, a hydrogen/oil ratio of 500 (V/V), and a weight hourly space velocity (WHSV) of 2.0 h-1, the conversion of DBT HDS was 96.0%.

Application of Response Surface Methodology for Ethanol Conversion into Hydrocarbons Using ZSM-5 Zeolites

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 617 ◽  
Author(s):  
José Faustino Souza de Carvalho Filho ◽  
Marcelo Maciel Pereira ◽  
Donato Alexandre Gomes Aranda ◽  
João Monnerat Araujo Ribeiro de Almeida ◽  
Eduardo Falabella Sousa-Aguiar ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Space Velocity ◽  
Light Olefins ◽  
Ethanol Conversion ◽  
Mesopore Volume ◽  
Weight Hourly Space Velocity ◽  
Standard Response ◽  
Benzene Toluene ◽  
Central Composite

The ethanol conversion into hydrocarbons (light olefins and aromatics) using alkali-treated HZSM-5 with different SiO2/Al2O3 ratios (23, 38, and 53) zeolites was evaluated. The desilicated SAR 38 zeolite exhibited significant growth on the external surface area (61–212 m2/g) and the mesopore volume (0.07–0.37 cm3/g) without significate reduction on XRD crystallinity (93%). All catalysts were active on the ethanol conversion into hydrocarbons. At the same set of variables, the alkali-treated HZSM-5 zeolites showed a better conversion and a high selectivity to C4–C9 hydrocarbons when compared to the parent microporous zeolites. Only the parent HZSM-5 zeolite (SAR 53) was chosen for the statistical study using the standard response surface methodology in combination with the central composite design. It was found that maximum BTEX (benzene, toluene, ethylbenzene, and xylenes) and minimum ethylene production were reached for the following conditions: temperature 450 °C, pressure 20 bar, and WHSV (weight hourly space velocity) 5 h−1.

Preparation of Nano Ni2P/TiO2-Al2O3 Catalyst and Catalytic Activity for Hydrodesulfurization

2014 ◽  
Vol 983 ◽  
pp. 71-74
Author(s):  
Hua Song ◽  
Zi Dong Wang ◽  
Zai Shun Jin ◽  
Feng Li ◽  
Huai Yuan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Temperature ◽  
Space Velocity ◽  
Impregnation Method ◽  
Catalyst Structure ◽  
Weight Hourly Space Velocity

nanonickel phosphide Ni2P catalysts supported on TiO2-Al2O3 support were prepared by impregnation. The catalysts were characterized by XRD, BET, and XPS. The effects of impregnation method,Ni2P loading on catalyst structure and HDS activity were studied. The results indicated that co-impregnation method is beneficial to the formation of Ni2P and can avoid the formation of Ni12P5. The catalyst prepared with co-impregnation method, Ni2P loading of 30% exhibited the best performance. At a reaction temperature of 606 K, a pressure of 3.0 MPa, a hydrogen/oil ratio of 500 (V/V), and a weight hourly space velocity (WHSV) of 2.0 h-1, the conversion of DBT HDS was 96.0%.

scholarly journals The Effect of the Reaction Conditions on the Properties of Products from Co-hydrotreating of Rapeseed Oil and Petroleum Middle Distillates

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 442
Author(s):  
Petr Straka ◽  
Josef Blažek ◽  
Daria Toullis ◽  
Tomáš Ihnát ◽  
Pavel Šimáček
Keyword(s):  
Reaction Temperature ◽  
Rapeseed Oil ◽  
Space Velocity ◽  
Gas Oil ◽  
Reaction Conditions ◽  
Total Conversion ◽  
Hydrogen Flow ◽  
Weight Hourly Space Velocity ◽  
Middle Distillates ◽  
Al2o3 Catalyst

This study compares the hydrotreating of the mixture of petroleum middle distillates and the same mixture containing 20 wt % of rapeseed oil. We also study the effect of the temperature and the weight hourly space velocity (WHSV) on the co-hydrotreating of gas oil and rapeseed oil mixture. The hydrotreating is performed over a commercial hydrotreating Ni-Mo/Al2O3 catalyst at temperatures of ca. 320, 330, 340, and 350 °C with a WHSV of 0.5, 1.0, 1.5, and 2.0 h−1 under a pressure of 4 MPa and at a constant hydrogen flow of 28 dm3·h−1. The total conversion of the rapeseed oil is achieved under all the tested reaction conditions. The content of the aromatic hydrocarbons in the products reached a minimum at the lowest reaction temperature and WHSV. The content of sulphur in the products did not exceed 10 mg∙kg−1 at the reaction temperature of 350 °C and a WHSV of 1.0 h−1 and WHSV of 0.5 h−1 regardless of the reaction temperature. Our results show that in the hydrotreating of the feedstock containing rapeseed oil, a large amount of hydrogen is consumed for the dearomatisation of the fossil part and the saturation of the double bonds in the rapeseed oil and its hydrodeoxygenation.

Methanol Dehydrogenation to Formaldehyde over Zinc Oxide-Modified Sodium Carbonate

2013 ◽  
Vol 750-752 ◽  
pp. 1826-1830
Author(s):  
Qing Song Wang ◽  
Gong Li ◽  
Min Jian Huang ◽  
Shu Xi Zhou
Keyword(s):  
Sodium Carbonate ◽  
Reaction Temperature ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Space Velocity ◽  
Methanol Dehydrogenation ◽  
Weight Hourly Space Velocity ◽  
Catalyst Composition ◽  
Grinding Method

Methanol dehydrogenation to formaldehyde was conducted in a fixed-bed flow reactor under the atmospheric pressure with sodium carbonate modified by metal oxides. The effects of catalyst composition, reaction temperature, weight hourly space velocity (WHSV) on the reaction were investigated. The catalysts were characterized by XRD, TG and nitrogen adsorption. The results indicated that ZnO/Na2CO3 containing 2wt% ZnO prepared by mechanical grinding method had higher catalytic activity for methanol dehydrogenation to formaldehyde. The conversion of methanol and the selectivity of formaldehyde were respectively 57.62% and 77.84% under the condition of wmethanol/wfeed =0.19, reaction temperature 650°C and WHSV (methanol) 7h-1.

scholarly journals A Study into the γ-Al2O3 Binder Influence on Nano-H-ZSM-5 via Scaled-Up Laboratory Methanol-To-Hydrocarbon Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1140
Author(s):  
Bonan Liu ◽  
Xiaochun Zhu ◽  
Jun Zhao ◽  
Duanda Wang ◽  
Wangjing Ma
Keyword(s):  
Scale Up ◽  
Early Period ◽  
Early Time ◽  
Space Velocity ◽  
Product Distribution ◽  
Catalytic Performance ◽  
Coke Deposition ◽  
Physical Strength ◽  
Weight Hourly Space Velocity ◽  
Methanol To Hydrocarbons

Development of a laboratory selected zeolite into an industrial zeolite-based catalyst faces many challenges due to the scaling-up of reaction which requires many upgrades of the as-prepared catalyst such as an enhanced physical strength. To meet this requirement zeolite powders are normally mixed with various binders and then shaped into bulky bodies. Despite the fact there are a lot of reports on the positive features brought by the shaping treatment, there is still a great need to further explore the zeolite properties after the binder introduction. In this case, a lot of studies have been continuously conducted, however, many results were limited due to the usage of much smaller laboratory samples rather than a real factory plant, and more importantly, the maximal/minimal proportion of zeolites in the shaped catalyst. In this research, our shaped catalysts are based on nano-H-ZSM-5 zeolites and alumina (γ–Al2O3) binder while keeping the zeolite content to a maximum. H-ZSM-5 samples and Al-H-ZSM-5 samples are compared in the designed methanol-to-hydrocarbons reaction. With a reduced weight-hourly-space-velocity (WHSV = 1.5 h−1) and a higher reaction pressure (6 bar) favorable for aromatization, together with the tailored instruments for catalyst volume scale-up (20 g samples are tested each time), our tests focus on the early period catalytic performance (during the first 5 h). Unlike a normal laboratory test, the results from the scaled-up experiments provide important guidance for a potential industrial application. The role of the γ–Al2O3 introduced, not only as binder, but also performing as co-catalyst, on tailoring the early time product distribution, and the corresponding coke deposition is systematically investigated and discussed in details. Notably, the Si/Al ratio of H-ZSM-5 still has a decisive influence on the reaction performance of the Al-H-ZSM-5 samples.

scholarly journals The effect of process parameters on catalytic direct CO2 hydrogenation to methanol

2021 ◽  
Vol 1195 (1) ◽  
pp. 012034
Author(s):  
M K Koh ◽  
Y J Wong ◽  
A R Mohamed
Keyword(s):  
Process Parameters ◽  
Reaction Temperature ◽  
Space Velocity ◽  
Xrd Analysis ◽  
Hydrogenation Reaction ◽  
Copper Surface ◽  
Methanol Production ◽  
Reaction Pressure ◽  
Weight Hourly Space Velocity ◽  
Methanol Formation

Abstract The direct CO2 hydrogenation to methanol is an attractive route to actively remove CO2 and to promote sustainable development. Herein, the performance of Cu-Zn-Mn catalyst supported on mesoporous silica KIT-6 (hereafter, CZM/KIT-6) for methanol synthesis by direct CO2 hydrogenation reaction was investigated by varying the process parameters, which included the weight-hourly space velocity, reaction temperature and reaction pressure. The CO2 conversion was found to decrease with the increase of WHSV. On the other hand, CO2 conversion increased with reaction temperature and pressure. Meanwhile, the methanol selectivity increased with WHSV and reaction pressure but decreased with the increase of reaction temperature. The apparent activation energy of methanol production at low reaction temperature (160 - 220 °C) was 10 kcal/mol. Non-Arrhenius behaviour of methanol formation was observed at high reaction temperature (220 - 260 °C). The performance of CZM/KIT-6 was maintained at high level, with the average methanol yield of 24.4 %, throughout the stability experiment (120-hour time-on-stream). In post-reaction XRD analysis, the copper crystallite growth was found to be 53.5 %, thus, resulting in 35.3 % loss of copper surface area.

scholarly journals Noble Metals-Based Catalysts for Hydrogen Production via Bioethanol Reforming in a Fluidized Bed Reactor

2020 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Concetta Ruocco ◽  
Vincenzo Palma ◽  
Marta Cortese ◽  
Marco Martino
Keyword(s):  
Noble Metals ◽  
Formation Rate ◽  
Space Velocity ◽  
Ethanol Conversion ◽  
Hydrogen Yield ◽  
Promising Candidate ◽  
Weight Hourly Space Velocity ◽  
Stability Performance ◽  
Steam Reforming Of Ethanol ◽  
Ethanol Stability

In this work, Pt-Ni/CeO2-SiO2, as well as Ru-Ni/CeO2-SiO2 catalysts, were obtained at different loadings of the noble metal (in the interval 0–3 wt%) and tested for oxidative steam reforming of ethanol. Stability performance was evaluated at 500 °C for 25 h under a steam to ethanol ratio of 4 and an oxygen to ethanol ratio of 0.5. The weight hourly space velocity was fixed to 60 h−1, which is considerably higher than the typical values selected for such processes. All the catalysts deactivated with time-on-stream, due to the severe operative conditions selected. However, the highest ethanol conversion (above 95%) and hydrogen yield (30%) at the end of the test were recorded over the 2 wt%Pt-10 wt%Ni/CeO2-SiO2 catalyst, which also displayed a limited carbon formation rate (1.5 × 10−6 gcoke·gcatalyst−1·gcarbon,fed−1·h−1, reduced almost 5 times compared to the samples that had a Pt or Ru content of 0.5 wt%). Thus, the latter catalyst was identified as a promising candidate for future tests under real bioethanol mixture.

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