scholarly journals Simulation of methanol production from residual biomasses in a Cu/ZnO/Al2O3 packed bed reactor

2020 ◽  
Author(s):  
Carlos Esteban Aristizabal-Alzate ◽  
Andrés Felipe Vargas-Ramírez ◽  
Pedro Nel Alvarado-Torres
Keyword(s):  
Pressure Drop ◽  
Heterogeneous System ◽  
Catalyst Deactivation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Deactivation Model ◽  
Alcohol Production ◽  
Methanol Production ◽  
Ratio Effect ◽  
Agent Selection

This article aims to simulate an algorithm constructed in MATLAB to represent the catalytic conversion of SYNGAS into methanol in a packed-bed reactor, based on chemical kinetics for a heterogeneous system with a Cu/ZnO/Al2O3 as a catalyst, and complementary math and phenomenological models, as a pressure drop and catalyst deactivation. Model validation is developed, comparing reference results and the results by running the algorithm in MATLAB using a reference SYNGAS composition. Also, the constructed model considers a catalyst deactivation by sintering and pressure drop along the reactor.  Several parameters were evaluated to identify the pro conditions for methyl alcohol production; these parameters include the gasifying agent selection, the biomass and steam ratio effect, and the biomass origin.

Investigations of Hydrodynamics and Heat Transfers in a Modified Reactor Using Fluid Mixers

2013 ◽  
Vol 805-806 ◽  
pp. 1250-1256
Author(s):  
Prayut Jiamrittiwong ◽  
Karn Pana-Suppamassadu ◽  
Phavanee Narataruksa ◽  
Sabaithip Tungkamani ◽  
Nuwong Chollacoop
Keyword(s):  
Catalyst Deactivation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Liquid Fuels ◽  
Mixed Gas ◽  
Static Mixers ◽  
Uniform Distributions ◽  
Temperature Distributions ◽  
Drop Flow ◽  
Heat Transfers

The performance of a packed-bed reactor typically used in Gas-to-Liquid (GTL) or Biomass-to-Liquid (BTL) technologies in producing liquid fuels was affected by unfavorable high pressure drop, flow and temperature maldistributions which in turn could cause severe catalyst deactivation, and result in inefficient reaction etc. A certain types of fluid mixers such as KenicsTM or Mixing & Stirring type static mixers had been suggested to improve the performance of this type of reactor. In order to design a proper modified reactor by mean of an installation of such mixing structures for the pilot plant in liquid fuel production via Fischer-Tropsch Synthesis (FTS) conducted at the RCC research center, this study had to characterize the hydrodynamics and heat transfers within a packed-bed modified by KenicsTM and Mixing & Stirring type static mixers. During the FTS, the syngas i.e. CO and H2 was fed through the bed of catalyst causing the temperature rise due to an exothermic enthalpy, and the flow and temperature distributions of mixed gas within the catalyst bed were influenced. The improved velocity and temperature distributions and heat transfers were exhibited by using such mixers e.g. rather uniform distributions and higher heat transfer coefficient. Thus, the better performance of the reactor could be expected.

scholarly journals Studies on Pyrolysis Kinetic of Newspaper Wastes in a Packed Bed Reactor: Experiments, Modeling, and Product Characterization

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Aparna Sarkar ◽  
Sudip De Sarkar ◽  
Michael Langanki ◽  
Ranjana Chowdhury
Keyword(s):  
Packed Bed ◽  
Nitrogen Atmosphere ◽  
Packed Bed Reactor ◽  
Experimental Conditions ◽  
Deactivation Model ◽  
Temperature Range ◽  
Product Characterization ◽  
Kinetic Rate Constants ◽  
Ft Ir ◽  
Pyrolysis Kinetic

Newspaper waste was pyrolysed in a 50 mm diameter and 640 mm long reactor placed in a packed bed pyrolyser from 573 K to 1173 K in nitrogen atmosphere to obtain char and pyro-oil. The newspaper sample was also pyrolysed in a thermogravimetric analyser (TGA) under the same experimental conditions. The pyrolysis rate of newspaper was observed to decelerate above 673 K. A deactivation model has been attempted to explain this behaviour. The parameters of kinetic model of the reactions have been determined in the temperature range under study. The kinetic rate constants of volatile and char have been determined in the temperature range under study. The activation energies 25.69 KJ/mol, 27.73 KJ/mol, 20.73 KJ/mol and preexponential factors 7.69 min−1, 8.09 min−1, 0.853 min−1of all products (solid reactant, volatile, and char) have been determined, respectively. A deactivation model for pyrolysis of newspaper has been developed under the present study. The char and pyro-oil obtained at different pyrolysis temperatures have been characterized. The FT-IR analyses of pyro-oil have been done. The higher heating values of both pyro-products have been determined.

Split Flow Modified Packed Bed Reactor for Cobalt Oxide Based High-Temperature TCES Systems

2019 ◽  
Author(s):  
Nasser Vahedi ◽  
Alparslan Oztekin
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Pressure Drop ◽  
Energy Density ◽  
Redox Reaction ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Flow Ratio ◽  
Packed Bed Reactors ◽  
Split Flow

Abstract The new generation of Concentrated Solar Power (CSP) plants requires high temperature and high energy density storage system with good cyclic stability. The potential solution satisfying such requirements is the thermochemical energy storage (TCES) using gas-solid redox reaction. Design of efficient storage reactor is very critical for applications of such storage systems. Packed bed reactors have a simpler design with no moving components and are more cost-effective compared to other available moving bed design configurations while having high-pressure drop is their main drawback. Any improvement in the pressure drop makes the design more suitable for commercial applications, especially at high temperature operating conditions. Cobalt oxide redox reaction has been considered for this study because of its unique features, especially high enthalpy of reaction (energy density) and high reaction temperature. A rectangular cross-section packed bed reactor with a large aspect ratio is selected as a reference conventional packed bed reactor. The novel split-flow packed bed reactor design configuration is proposed in which a portion of heat transfer fluid is passed through adjacent side channels. The split flow ratio of 1/3 has been considered for the case study. The transient two-dimensional numerical model is developed for solving mass, momentum, and energy equations for both gas and solid phases using suitable reaction kinetics for the reversible reduction and re-oxidation process. Complete storage cycle, including both the charging and discharging mode, has been simulated using finite element method. The split flow design performance is compared with the reference case considering the same size of the reaction bed. It is shown that the conversion time is increased while the pressure drop reduced below half of the pressure loss of the conventional design. Reduced mass flow rate passing through the bed results in considerable improvement in required pressure work with a penalty of storage performance. Further study is needed to optimize the split flow ratio and the surface heat transfer characteristics of the bed. The proposed design configuration could be a breakthrough in packed bed reactors, especially for high-temperature storage applications.

A Novel Reactor Configuration for Industrial Methanol Production From the Synthesis Gas

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Payam Parvasi ◽  
Seyyed Mohammad Jokar
Keyword(s):  
Methanol Synthesis ◽  
Radial Flow ◽  
Cooling Water ◽  
Packed Bed ◽  
Optimization Methods ◽  
Packed Bed Reactor ◽  
Flow Reactors ◽  
Methanol Production ◽  
Reactor Models ◽  
The Cost

In this work, the methanol synthesis on a commercial industrial catalyst in a novel cylindrical radial flow packed-bed reactor is investigated. The adiabatic and nonadiabatic cylindrical radial flow reactors were proposed and modeled in this research. The proposed configuration has been compared with conventional reactor for methanol production. It leads to higher methanol production and lower pressure drop, with the same catalyst consumption. Furthermore, the results show that the nonadiabatic radial flow packed-bed reactor has a higher methanol content compared with the adiabatic one. The improvement in methanol production was studied by optimizing the essential parameters such as inlet temperatures of the feed and cooling water as well as the number of cooling tubes. The nonlinearity and complexity of the reactor models make the traditional optimization methods ineffective and improbable. Therefore, the process was optimized by genetic algorithm (GA) method, which is one of the most powerful methods. The optimum values for the number of cooling tubes, feed and cooling water temperatures were 308, 507.6 K, and 522.43 K, respectively. The optimization results showed that a new reactor design could be proposed to reduce the cost of methanol synthesis.

Modeling of an axial flow, spherical packed-bed reactor for naphtha reforming process in the presence of the catalyst deactivation

2010 ◽  
Vol 35 (23) ◽  
pp. 12784-12799 ◽  
Author(s):  
D. Iranshahi ◽  
E. Pourazadi ◽  
K. Paymooni ◽  
A.M. Bahmanpour ◽  
M.R. Rahimpour ◽  
...  
Keyword(s):  
Catalyst Deactivation ◽  
Axial Flow ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Naphtha Reforming

scholarly journals Simulation of Methanol Synthesis in Packed Bed Reactor for Utilization of CO2 from Acid Gas Removal Unit

2018 ◽  
Vol 67 ◽  
pp. 03005
Author(s):  
Bayu Sari Adji ◽  
Yuswan Muharam ◽  
Sutrasno Kartohardjono
Keyword(s):  
Oil And Gas ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Small Scale ◽  
Production Plant ◽  
High Concentration ◽  
Methanol Production ◽  
Acid Gas ◽  
Oil And Gas Fields ◽  
Gas Removal

There are many oil and gas fields in Indonesia which contain high CO2 that need to be treated. The Acid Gas Removal Unit (AGRU) is installed to remove the CO2. The AGRU will release the CO2 gas from the regeneration column. It still contains a high concentration of CO2 (higher than 80%). The accumulation of CO2 emission to the atmosphere will impact the environment. To promote environment-friendly technology, the process can be improved with conversion of CO2 into methanol. It will provide a relatively closed loop of the carbon cycle and as a renewable energy alternative. This study aims to provide packed bed reactor design which can be implemented in the small-scale methanol production plant utilizing high CO2 feed gas. The reactor temperature was varied from 200°C to 250°C and pressure were operated in the range of 40 Bar up to 75 Bar. These variations were used to analyze the effects of methanol production. The simulation results showed that peak methanol production rate was achieved at the temperature around 230°C. As the conclusion, the reactor showed better performance at the higher pressure and higher temperature although the reaction is exothermic including the recycling process can reduce the cost of hydrogen.

Selective Oxidation of Ethylene in an Industrial Packed-Bed Reactor: Modelling, Analysis and Optimization

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Omar Galan ◽  
Vincent G Gomes ◽  
Jose Romagnoli ◽  
Kian F Ngian
Keyword(s):  
Ethylene Oxide ◽  
Catalyst Deactivation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Coolant Temperature ◽  
Modelling Analysis ◽  
Composition Profiles ◽  
Plant Data ◽  
Personnel Safety ◽  
Optimal Set

This work is focused on the modelling, analysis and optimization of industrial ethylene oxide production in a packed bed reactor. The aim is to identify the critical variables that maximize the reactor productivity in an existing facility without compromising personnel safety and equipment integrity. The chemical reactions involved are highly exothermic making the internal temperature control of this unit a challenging task. Temperature excursions at dangerous levels have been experienced due to variations in composition and temperature of fresh feed to the reactor. Therefore, the prediction of dynamic temperature and composition profiles in the reactor are important for its safe operation. The model we developed incorporates catalyst deactivation and the effect of an inhibitory agent: 1,2-dichloroethene. The model predictions were found to be in good agreement with the plant data. Our model-based optimization studies show that the optimal set point for the inlet coolant temperature is suitable for preventing reactor hot spots and maximizing ethylene oxide selectivity. The heat integration aspects of the process were addressed.

Immobilized Whole Cells as Effective Catalysts for Chiral Alcohol Production

2009 ◽  
Vol 62 (9) ◽  
pp. 1034 ◽  
Author(s):  
Jeck Fei Ng ◽  
Stephan Jaenicke
Keyword(s):  
Flow Reactor ◽  
Batch Reactor ◽  
Enantiomeric Excess ◽  
Lactobacillus Brevis ◽  
Packed Bed ◽  
Alginate Beads ◽  
Packed Bed Reactor ◽  
Process Conditions ◽  
Alcohol Production ◽  
Whole Cells

Recombinant Escherichia coli overexpressing the gene LbADH, which encodes for an alcohol dehydrogenase from Lactobacillus brevis, was successfully transformed and cultured. The cells are able to catalyze the reduction of pro-chiral ketones, e.g. ethyl acetoacetate into R-(–)ethyl hydroxybutyrate (EHB) with high conversion and enantiomeric excess >99%. Immobilizing the whole cells in alginate beads leads to a catalyst with improved stability and ease of handling while maintaining the high activity of the free cells. The whole-cell catalyst was tested in a stirred batch reactor (CSTR) and in a continuously operated packed-bed reactor. An Mg2+ concentration of 2 mM was crucial for maintaining the activity of the biocatalyst. After a partial optimization of the process conditions, a productivity of 1.4 gEHB gwcw–1 h–1 could be maintained in a continuous flow reactor over a prolonged period of time.

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