scholarly journals Evaluation of the Parameters and Conditions of Process in the Ethylbenzene Dehydrogenation with Application of Permselective Membranes to Enhance Styrene Yield

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Paulo Jardel P. Araújo ◽  
Manuela Souza Leite ◽  
Teresa M. Kakuta Ravagnani
Keyword(s):  
Composite Membrane ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Catalytic Dehydrogenation ◽  
Experimental Conditions ◽  
Ethylbenzene Dehydrogenation ◽  
Weight Hourly Space Velocity ◽  
Membrane Geometry ◽  
Secondary Reactions

Styrene is an important monomer in the manufacture of thermoplastic. Most of it is produced by the catalytic dehydrogenation of ethylbenzene. In this process that depends on reversible reactions, the yield is usually limited by the establishment of thermodynamic equilibrium in the reactor. The styrene yield can be increased by using a hybrid process, with reaction and separation simultaneously. It is proposed using permselective composite membrane to remove hydrogen and thus suppress the reverse and secondary reactions. This paper describes the simulation of a dehydrogenation process carried out in a tubular fixed-bed reactor wrapped in a permselective composite membrane. A mathematical model was developed, incorporating the various mass transport mechanisms found in each of the membrane layers and in the catalytic fixed bed. The effects of the reactor feed conditions (temperature, steam-to-oil ratio, and the weight hourly space velocity), the fixed-bed geometry (length, diameter, and volume), and the membrane geometry (thickness of the layers) on the styrene yield were analyzed. These variables were used to determine experimental conditions that favour the production of styrene. The simulation showed that an increase of 40.98% in the styrene yield, compared to a conventional fixed-bed process, could be obtained by wrapping the reactor in a permselective composite membrane.

scholarly journals Promotional Effect of Cu, Fe and Pt on the Performance of Ni/Al2O3 in the Deoxygenation of Used Cooking Oil to Fuel-Like Hydrocarbons

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
Gisele C. R. Silva ◽  
Dali Qian ◽  
Robert Pace ◽  
Olivier Heintz ◽  
Gilles Caboche ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Pt Catalyst ◽  
Cooking Oil ◽  
Weight Hourly Space Velocity ◽  
Used Cooking Oil ◽  
Promotional Effect ◽  
Comparable Performance ◽  
Cu Catalyst

Inexpensive Ni-based catalysts can afford comparable performance to costly precious metal formulations in the conversion of fat, oil, or greases (FOG) to fuel-like hydrocarbons via decarboxylation/decarbonylation (deCOx). While the addition of certain metals has been observed to promote Ni-based deCOx catalysts, the steady-state performance of bimetallic formulations must be ascertained using industrially relevant feeds and reaction conditions in order to make meaningful comparisons. In the present work, used cooking oil (UCO) was upgraded to renewable diesel via deCOx over Ni/Al2O3 promoted with Cu, Fe, or Pt in a fixed-bed reactor at 375 °C using a weight hourly space velocity (WHSV) of 1 h−1. Although all catalysts fully deoxygenated the feed to hydrocarbons throughout the entire 76 h duration of these experiments, the cracking activity (and the evolution thereof) was distinct for each formulation. Indeed, that of the Ni-Cu catalyst was low and relatively stable, that of the Ni-Fe formulation was initially high but progressively dropped to become negligible, and that of the Ni-Pt catalyst started as moderate, varied considerably, and finished high. Analysis of the spent catalysts suggests that the evolution of the cracking activity can be mainly ascribed to changes in the composition of the metal particles.

Effect of the Reduction Temperature on Nickel Phosphide Catalyst Structure and Catalytic Activity for Hydrodesulfurization

2014 ◽  
Vol 1025-1026 ◽  
pp. 782-786 ◽  
Author(s):  
Hua Song ◽  
Fu Yong Zhang ◽  
Zai Shun Jin ◽  
Huai Yuan Wang ◽  
Yan Ji Zhu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Reduction Temperature ◽  
Catalyst Structure ◽  
X Ray ◽  
Weight Hourly Space Velocity ◽  
Transmission Electron ◽  
Nickel Phosphate

Ni2P/TiO2-Al2O3catalysts were prepared by impregnation of nickel phosphate precursors followed by reduction in hydrogen. The catalysts were characterized by X-ray diffraction (XRD), N2-adsorption specific surface area measurements (BET), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetry differential thermal analysis (TG-DTA). The effects of reduction temperature on catalyst structure and HDS activity were studied using a lab-scale continuous flow fixed-bed reactor.. The results indicated that the catalyst prepared with reduction temperature of 973 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%.

scholarly journals Kinetic study of carbon monoxide methanation over mesoporous Ni-Mo catalyst prepared by a hydrothermal method

2019 ◽  
Vol 44 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Zhang Jiaying
Keyword(s):  
Carbon Monoxide ◽  
Design Method ◽  
Orthogonal Design ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Weight Hourly Space Velocity ◽  
Mo Catalyst ◽  
Proposed Model ◽  
Orthogonal Design Method

The kinetics of carbon monoxide methanation over Ni-Mo-SiO2 catalyst were studied. The model was developed based on catalyst tests carried out in a fixed-bed reactor at a reaction temperature varied from 300 °C to 450 °C under a pressure from 0.1 to 1.5 MPa with a weight hourly space velocity of 60,000 mL h−1 g−1. An orthogonal design method was adopted to select test points with temperature, pressure, and feed compositions as factors. Based on the experimental observations, a Langmuir–Hinshelwood equation kinetic model was formulated and its parameters were estimated by fitting the experimental data implemented in MATLAB. The activation energy for the formation of CH4 was 45.4 kJ mol−1 and comparing the experimental and model-predicted data showed that the proposed model gives a reasonable fit with an average absolute relative deviation of ±9.8%.

scholarly journals Evaporated Palm Oil Cracking To Gasoline Over Zeolite Catalysts

2012 ◽  
Author(s):  
Tirena Bahnur Siregar ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Reaction Temperature ◽  
Palm Oil ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Space Velocity ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Gaseous Products ◽  
Weight Hourly Space Velocity ◽  
Oil Cracking

Peretakan bermangkin minyak kelapa sawit kepada gasolin menggunakan H–ZSM–5 dan H–Beta dijalankan pada tekanan atmosfera dan kadar alir mengikut berat 2.5 jam–1. Suhu tindak balas ditetapkan dalam julat 450°C to 525°C. Mangkin yang dikalsinkan telah dicirikan menggunakan teknik pembelauan sinar X, penjerapan piridina–spektrofotometri inframerah dan penjerapan nitrogen. Hasil cecair dan gas dianalisis menggunakan kromatografi gas (FID) dan (TCD). Peningkatan suhu tidak balas meninggikan penukaran minyak kelapa sawit. Penukaran minyak kelapa sawit dan kepemilihan gasolin tertinggi diperolehi dengan mangkin H–ZSM–5, masing–masing ialah 96.12% berat dan 29.92% berat. Walaupun penukaran minyak kelapa sawit dan kepemilihan gasolin untuk kedua–dua mangkin adalah tinggi, tetapi H–ZSM–5 menunjukkan hasil yang lebih baik berbanding H–Beta pada semua suhu. Gasolin yang dihasilkan menggunakan H–ZSM–5 mempunyai kandungan naftena yang tinggi, diikuti oleh isoparafin, olefin, aromatik dan sedikit paraffin, manakala gasolin yang terhadil menggunakan H–Beta mengandungi olefin, naftena, paraffin dan aromatik. Hasil sampingan utama adalah gas yang terdiri daripada komponen C1–C3 menggunakan H–ZSM–5 dan C3–C4 menggunakan H–Beta Kata kunci: Zeolit; H–ZSM–5; H–Beta; peretakan; minyak kelapa sawit; gasolin The catalytic cracking of palm oil to gasoline over H–ZSM–5 and H–Beta was studied in fixed bed reactor operated at atmospheric pressure and weight hourly space velocity (WHSV) of 2.5 h–1. The reaction temperature was varied between 450°C to 525°C. The calcined catalysts were characterized using X–Ray Diffraction (XRD), Pyridine Adsorption–Infrared Spectrophotometry (Py–IR) and Nitrogen Adsorption (NA) methods. The liquid and gaseous products were analyzed using (FID) and (TCD) gas chromatography respectively. Increase in reaction temperature led to higher palm oil conversion. The highest conversion and gasoline selectivity obtained at 525°C were 96.12 wt% and 29.92 wt% respectively with H–ZSM–5. Although the conversion and the gasoline selectivity of both catalysts was high, but H–ZSM–5 performed better than H–Beta at all temperature range. Gasoline produced using H–ZSM–5 consisted mainly of naphthenes beside isoparaffins, olefins, aromatics and a small amount of paraffins, while the gasoline obtained by using H–Beta contained olefins, naphthenes, paraffins and aromatics. Gas was the major side product, which consisted mainly of C1–C3 for using H–ZSM–5 and C3–C4 compounds for using H–Beta. Key words: Zeolite; H–ZSM–5; H–Beta; cracking, palm oil; gasoline

Research on the Catalytic Activity of MnyCezOx/TiO2 for Ethyl Acetate Oxidation

2013 ◽  
Vol 781-784 ◽  
pp. 308-311 ◽  
Author(s):  
Xin Li ◽  
Wei Su ◽  
Qi Bin Xia ◽  
Zhi Meng Liu
Keyword(s):  
Catalytic Activity ◽  
Ethyl Acetate ◽  
High Activity ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Acetate Oxidation ◽  
Acetate Concentration ◽  
Molar Ratios

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.

scholarly journals The Effect of Pyrolysis Temperature on Copyrolysis of Lignite and Pistachio Seed in a Fixed-bed Reactor

2021 ◽  
Vol 15 ◽  
pp. 49-52
Author(s):  
Özlem Onay
Keyword(s):  
Elemental Analysis ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Product Distribution ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Oil Yield ◽  
Pyrolysis Oil ◽  
Nitrogen Gas ◽  
Experimental Conditions

Co-pyrolysis of lignite and pistachio seed (CPLPS) under nitrogen gas was performed in a Heinze retort. The effect of pyrolysis temperature on product distribution of CPLPS investigated under heating rate of 10°Cmin-1 and blending ratio of 50(wt)%. Biomass is higher yield to be pyrolyzed than lignite and addition of biomass promotes the pyrolysis of lignite. In the range of the experimental conditions investigated the yield of the product is proportional to pyrolysis temperature. On the other hand, considerable synergetic effects were observed during the co-pyrolysis in a fixed bed reactor leading to increase in oil yield. Maximum pyrolysis oil yield of 27.2% was obtained at pyrolysis temperature of 550°C. The obtained oils are characterized by GC, and elemental analysis.

scholarly journals Kinetika Reaksi Hidrogenasi Ester Lemak Menjadi Alkohol Lemak Dengan Katalis Tembaga- Mangan

2020 ◽  
Vol 8 (1) ◽  
pp. 21-27
Author(s):  
Melia Laniwati Gunawan ◽  
IGBN Makertihartha ◽  
Subagjo Subagjo
Keyword(s):  
Kinetic Equation ◽  
Fixed Bed ◽  
Acid Methyl Ester ◽  
Space Velocity ◽  
Lauryl Alcohol ◽  
Fixed Bed Reactor ◽  
Commercial Catalyst ◽  
Copper Manganese ◽  
High Pressure Reaction ◽  
Copper Based Catalyst

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.

Denitrification Activities of Mo-V-Ti Catalysts Prepared by Dipping Method at Low Temperature

2018 ◽  
Vol 913 ◽  
pp. 900-906
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Di Yin ◽  
Yuan Huang ◽  
Rui Min Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Conversion Efficiency ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Optimum Ratio ◽  
Denitrification Activity ◽  
Gas Space

Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. The experimental condition is NO: 500ppm, NH3:500ppm, O2:8%, SO2:100ppm, N2: equilibrium gas, space velocity: 36000h-1. Results indicate that the catalyst prepared by dipping method had good denitrification activity and sulfur resistance at low temperature. The optimum ratio of catalyst was 3V2O5-6MoO3-91TiO2 (wt %). The conversion efficiency of NO was 80~93%, and the conversion efficiency of SO2 was less than 1% at 180~260 °C.

Population dynamics in an aerobic submerged fixed bed reactor (ASFBR) process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 257-260 ◽  
Author(s):  
I. Lorda-de-los-Ríos ◽  
E. Bécares-Mantecón ◽  
I. Tejero-Monzón
Keyword(s):  
Population Dynamics ◽  
Oxygen Concentration ◽  
Fixed Bed ◽  
High Load ◽  
Fixed Bed Reactor ◽  
Synthetic Wastewater ◽  
Organic Load ◽  
Experimental Conditions ◽  
Low Load ◽  
Aeration Conditions

In this study, an aerobic submerged fixed bed reactor's (ASFBR) population dynamics has been studied in order to know its behavior in different conditions of organic load and oxygen concentration. The reactor was fed with synthetic wastewater. Tested variables and applied values were: 1) Variations in organic load (OL): 16–65 g COD/m2/d. 2) Variations in influent's COD concentration: 40–400 g COD/m3. 3) Variations in specific air flow (SAF): 15–127 m3air/kgCOD. Biofilm samples were taken at the top of the reactor. This study showed important variations in the composition and abundance of the microfauna depending on the experimental conditions. Variations in influent concentration had no significant effect on the abundance of the studied groups. However, differences depending on organic load and aeration conditions were observed. Organic load influenced every group studied but with different results. Sessile cilliates, metazoa and flagellates were abundant in low load, while crawling ones were in high load. Aeration intensity influenced most of the groups except Peranema and Vorticella spp. Despite obtaining good yields, not many protozoa, typical of biofilms under conventional processes, were found. Thus, a great variety of microorganisms, such as many classes of sessile and crawling cilliates, were not found. Important nitrifying activity was obtained at 20 cm depth in a bed. From this point, the heterotrophic and nitrifying populations exist but are inactive.

scholarly journals Microwave-assisted direct synthesis of butene from high-selectivity methane

2017 ◽  
Vol 4 (12) ◽  
pp. 171367
Author(s):  
Yi-heng Lu ◽  
Kang Li ◽  
Yu-wei Lu
Keyword(s):  
Methane Conversion ◽  
Liquid Fuel ◽  
Impact Ionization ◽  
Direct Synthesis ◽  
Fixed Bed ◽  
Volume Ratio ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Ionization Mass ◽  
Catalytic Dehydrogenation

Methane was directly converted to butene liquid fuel by microwave-induced non-oxidative catalytic dehydrogenation under 0.1–0.2 MPa. The results show that, under microwave heating in a two-stage fixed-bed reactor, in which nickel powder and NiO x –MoO y /SiO 2 are used as the catalyst, the methane–hydrogen mixture is used as the raw material, with no acetylene detected. The methane conversion is more than 73.2%, and the selectivity of methane to butene is 99.0%. Increasing the hydrogen/methane feed volume ratio increases methane conversion and selectivity. Gas chromatography/electron impact ionization/mass spectrometry chromatographic analysis showed that the liquid fuel produced by methane dehydrogenation oligomerization contained 89.44% of butene, and the rest was acetic acid, ethanol, butenol and butyric acid, and the content was 1.0–3.0 wt%.

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