scholarly journals Preparation of Pt-Zeolite Catalyst for Conversion of n-Octanol

2010 ◽  
Vol 1 (2) ◽  
pp. 90-97
Author(s):  
I Made Sadiana ◽  
Iip Izul Falah ◽  
Triyono Triyono
Keyword(s):  
Flow Rate ◽  
Zeolite Catalyst ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Hydrogen Gas ◽  
Fixed Bed Reactor ◽  
Activity Increase ◽  
Activity Test ◽  
Nitrogen Stream ◽  
Oxygen Gas

Pt-zeolite catalyst has been prepared by immersing a sample of zeolite in PtCl4 solution. After separation, the sample was dried and calcinated at 550 °C for 4 hours under nitrogen stream. Furthermore, the sample was oxidized with oxygen gas at 350 °C for 2 hours and reduced with hydrogen gas at 400 °C for 2 hours. Total amount of impregnated metal, acidity and surface are of the samples were determined by using atomic absorption spectrophotometric, gravimetric and gas sorption methods, respectively. The activity test was done in a fixed bed reactor and the results of the reaction were analyzed by using gas chromatograph. The result of the characterization showed that the higher total amount of impregnated metal, the lower the surface area and total volume of pores. The acidity and the catalyst activity increase with the increasing of the total amount of impregnated metal. The flow rate of feed and temperature reaction also influence yield conversion. The optimum yield of n-octanol conversion was obtained at 400 °C with the showest flow rate of n-octanol and flow rate of H2 gas was equal to 40 mL/minute.

scholarly journals Stable Continuous Production of γ-Valerolactone from Biomass-Derived Levulinic Acid over Zr–Al-Beta Zeolite Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Clara López-Aguado ◽  
Marta Paniagua ◽  
Juan A. Melero ◽  
Jose Iglesias ◽  
Pablo Juárez ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Hydrogen Transfer ◽  
Zeolite Catalyst ◽  
Continuous Production ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Transfer Hydrogenation ◽  
Fixed Bed Reactor ◽  
Beta Zeolite ◽  
Thermal Regeneration

The one-pot conversion of biomass-derived platform molecules such as levulinic acid (LA) and furfural (FAL) into γ-valerolactone (GVL) is challenging because of the need for adequate multi-functional catalysts and high-pressure gaseous hydrogen. As a more sustainable alternative, here we describe the transfer hydrogenation of LA to GVL using isopropanol as a hydrogen donor over a Zr-modified beta zeolite catalyst in a continuous fixed-bed reactor. A stable sustained production of GVL was achieved from the levulinic acid, with both high LA conversion (ca. 95%) and GVL yield (ca. 90%), for over at least 20 days in continuous operation at 170 °C. Importantly, the small decay in activity can be advantageously overcome by the means of a simple in situ thermal regeneration in the air atmosphere, leading to a complete recovery of the catalyst activity. Key to this outstanding result is the use of a Zr-modified dealuminated beta zeolite with a tailored Lewis/Brønsted acid sites ratio, which can synergistically catalyze the tandem steps of hydrogen transfer and acid-catalyzed transformations, leading to such a successful and stable production of GVL from LA.

Optimal catalyst activity profiles in pellets. 5. Optimization of the isothermal fixed-bed reactor

1986 ◽  
Vol 25 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Massimo Morbidelli ◽  
Alberto Servida ◽  
Sergio Carra ◽  
Arvind Varma
Keyword(s):  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor

Experimental Study of the Reforming of Methane with Carbon Dioxide over Coal Char

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Yanbing Li ◽  
Rui Xiao ◽  
Baosheng Jin ◽  
Huiyan Zhang
Keyword(s):  
Carbon Dioxide ◽  
Flow Rate ◽  
Fixed Bed ◽  
Coke Oven ◽  
Fixed Bed Reactor ◽  
Internal Diameter ◽  
Generation System ◽  
Coke Oven Gas ◽  
Surface Areas ◽  
Conversion Of Methane

As one of the fundamental issues of the new poly-generation system on the basis of gasification gas and coke oven gas, carbon dioxide reforming of methane experiments have been performed over coal chars derived from different parent coals in a lab-scale fixed-bed reactor (internal diameter 12 mm, length 700 mm). The char derived from TongChuan coal exhibited higher activity than other samples employed under the same conditions. After the reforming reaction, the char samples were covered with different amounts of carbon deposition which resulted in the surface areas decrease. As the flow rate of feed gas increased from 200 ml/min to 600 ml/min over the Xuzhou char sample at 1050 degrees Celsius, the conversion of methane decreased from 52.7% to 17.5% and the H2 /CO dropped from 0.75 to 0.55. While maintaining the flow rate of CO2 at 20ml/min at 1050 degrees Celsius, the mole ratio of reactants CH4/CO2 was varied from 1 to 1.75 which led to the H2/CO ratio increase from 0.75 to 1.2.

Dynamics and Control of an Adiabatic Fixed Bed Reactor with Varying Catalyst Activity

1986 ◽  
Vol 19 (15) ◽  
pp. 267-272 ◽  
Author(s):  
L. Goldschmidt ◽  
L. Hallager ◽  
S.B. Jorgensen
Keyword(s):  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Dynamics And Control ◽  
And Control

scholarly journals Dynamic Simulation of Adiabatic Catalytic Fixed-Bed Tubular Reactors: A Simple Approximate Modeling Approach

2014 ◽  
Vol 14 (1) ◽  
pp. 25
Author(s):  
Wiwut Tanthapanichakoon ◽  
Shinichi Koda ◽  
Burin Khemthong
Keyword(s):  
Dynamic Model ◽  
Dynamic Behavior ◽  
Dynamic Simulation ◽  
Flow Rate ◽  
Fixed Bed ◽  
Axial Dispersion ◽  
Fixed Bed Reactor ◽  
Inlet Temperature ◽  
Acetylene Hydrogenation ◽  
Tubular Reactors

Fixed-bed tubular reactors are used widely in chemical process industries, for example, selective hydrogenation of acetylene to ethylene in a naphtha cracking plant. A dynamic model is required when the effect of large fluctuations with time in influent stream (temperature, pressure, flow rate, and/or composition) on the reactor performance is to be investigated or automatically controlled. To predict approximate dynamic behavior of adiabatic selective acetylene hydrogenation reactors, we proposed a simple 1-dimensional model based on residence time distribution (RTD) effect to represent the cases of plug flow without/with axial dispersion. By modeling the nonideal flow regimes as a number of CSTRs (completely stirred tank reactors) in series to give not only equivalent RTD effect but also theoretically the same dynamic behavior in the case of isothermal first-order reactions, the obtained simple dynamic model consists of a set of nonlinear ODEs (ordinary differential equations), which can simultaneously be integrated using Excel VBA (Visual BASIC Applications) and 4th-order Runge-Kutta algorithm. The effects of reactor inlet temperature, axial dispersion, and flow rate deviation on the dynamic behavior of the system were investigated. In addition, comparison of the simulated effects of flow rate deviation was made between two industrial-size reactors.Keywords: Dynamic simulation, 1-D model, Adiabatic reactor, Acetylene hydrogenation, Fixed-bed reactor, Axial dispersion effect

Optimal catalyst activity distribution in fixed-bed reactor with catalyst deactivation

1989 ◽  
Vol 54 (2) ◽  
pp. 375-387 ◽  
Author(s):  
Jozef Markoš ◽  
Alena Brunovská
Keyword(s):  
Catalyst Deactivation ◽  
Active Catalyst ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Catalytic Reactor ◽  
Reactor Performance ◽  
Thiele Modulus ◽  
Activity Distribution ◽  
Parameter Ratio

In this paper the influence of the active catalyst location in a pellet on fixed-bed catalytic reactor performance is described. The optimal activity distribution as a function of an economic parameter (ratio of product and catalyst costs), Thiele modulus and Damkohler number is estimated.

scholarly journals Aldol Condensation of Cyclohexanone and Furfural in Fixed-Bed Reactor

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1068
Author(s):  
Zdeněk Tišler ◽  
Pavla Vondrová ◽  
Kateřina Hrachovcová ◽  
Kamil Štěpánek ◽  
Romana Velvarská ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Heterogeneous Catalysts ◽  
Mixed Oxides ◽  
Aldol Condensation ◽  
Condensation Reaction ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Chemical Properties ◽  
Fixed Bed Reactor ◽  
Molar Ratio

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.

scholarly journals Kinetic Model of Crude Palm Oil Hydrocracking Over Ni/Mo ZrO2–Pillared Bentonite Catalyst

2019 ◽  
Vol 64 (2) ◽  
pp. 238-247 ◽  
Author(s):  
Hasanudin Hasanudin ◽  
Addy Rachmat ◽  
Muhammad Said ◽  
Karna Wijaya
Keyword(s):  
Kinetic Model ◽  
Palm Oil ◽  
Rate Constants ◽  
Catalyst Activity ◽  
Fixed Bed ◽  
Diesel Oil ◽  
Fixed Bed Reactor ◽  
Crude Palm Oil ◽  
Reaction Models ◽  
Oil Gas

Crude Palm Oil hydrocrcaking has been carried out over Ni/Mo ZrO2–pillared bentonite catalyst in a fixed bed reactor. Crude Palm Oil hydrocracking over Ni/Mo ZrO2–pillared bentonite catalyst formed 3 products i.e. gas, oil and coke. The oil product from Crude Palm Oil hydrocracking was analyzed by using gas chromatography to determine its composition. Three types of fraction were classified i.e. gasoline, kerosene and diesel oil. In this research, the focused of the study is of hydrocracking kinetics by using lump kinetic models. The kinetic model was solved by using the software MATLAB R2018b involves the effect of catalyst activity on the reaction rate. The results of the kinetic study show that the 4-lump (Crude Palm Oil, gas coke and oil) and 6-lump reaction models (Crude Palm Oil, gas, coke, gasoline, kerosene and diesel) can be used to explain the Crude Palm Oil hydrocracking over Ni/Mo ZrO2–pillared bentonite catalyst. The 4-lump kinetic model has 5 rate constants and the 6-lump kinetic model has 14 rate constants.

Model prediction on the reliability of fixed bed reactor for ammonia production

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mole Fraction ◽  
Research Work ◽  
Fixed Bed ◽  
Hydrogen Gas ◽  
Fixed Bed Reactor ◽  
Ammonia Production ◽  
Feed Composition ◽  
Optimum Yield ◽  
Functional Parameters ◽  
Yield Factor

In this research work Haber process was employed to examine the reliability of the functional parameters and coefficient on ammonia production using the fixed bed reactor with hydrogen gas and nitrogen used as the main source of the reactant. Mathematical models were developed to monitor and predict the effectiveness factors, nitrogen fractional conversion, temperature, component mole fraction, hydrogen mole fraction, and ammonia mole fraction profile for the various cases considered during the investigation. The simulated parameters for case 1, 2 and 3 for components of total feed flow, pressure, reactor bed volume and feed composition influence the reliability of the functional parameters and the coefficient of the fixed bed reactor for optimum yield of ammonia. The developed models were simulated using Matlab program to evaluate the functional parameters and the results obtained from the system in terms of optimum yield factor indicate 30% to 34% increase in ammonia production. The increase in the performance evaluation concept revealed the reliability of the developed model in monitoring and predicting the rate of production of ammonia in a fixed bed reactor.

The Effects of Methanol on Honehe Lignite Pyrolysis

2013 ◽  
Vol 291-294 ◽  
pp. 748-754
Author(s):  
De Min He ◽  
Jun Guan ◽  
Lin Zhang ◽  
Qiu Min Zhang
Keyword(s):  
Flow Rate ◽  
Functional Group ◽  
Coal Tar ◽  
Fixed Bed ◽  
Holding Time ◽  
Fixed Bed Reactor ◽  
Coal Pyrolysis ◽  
Oxygen Functional Group ◽  
N2 Atmosphere ◽  
N2 Flow Rate

In this paper, the pyrolysis of Honehe Lignite in N2 and N2-Methanol atmospheres were investigated on a fixed-bed reactor. The methanol flow rate, pressure, temperature and holding time were studied. The maximum of coal tar yields 12.01% (with methanol injected in) and 9.61% (absence of methanol) were achieved on the conditions of 520°C, 0.5MPa, N2 flow rate 50ml/min, methanol flow rate 0.1ml/min and holding time 20min, and the relative growing rate was about 25.0%. The gas from coal pyrolysis was detected by GC, and the coal tar was reprocessed and then detected by GC-MS. While the solid char was detected by IR to study the change of oxygen functional group during coal pyrolysis in N2-Methanol atmosphere. Compared with that pyrolysis in N2 atmosphere, the components, characteristics and properties of coal tar, gas and solid char varied a lot. The results showed that the injection of methanol into the system changed the products yields and distribution. The results showed that the total yields of phenol, cresol and xylenol (short for PCX) in the Acidic were about 1.93% and 1.15% (daf) in two atmospheres respectively, the PCX yields with methanol injected was about 1.67 times higher than that absence of methanol.

Sign in / Sign up

Export Citation Format

Share Document