scholarly journals Pemodelan dan simulasi reverse flow reactor untuk oksidasi katalitik metana: pengembangan prosedur operasi start-up

2018 ◽  
Vol 10 (2) ◽  
pp. 70
Author(s):  
Yogi Wibisono Budhi ◽  
Teguh Kurniawan ◽  
Yazid Bindar
Keyword(s):  
Thermal Condition ◽  
Flow Reactor ◽  
Switching Time ◽  
Reverse Flow ◽  
Energy Requirement ◽  
Homogeneous Model ◽  
Modelling And Simulation ◽  
Heterogeneous Model ◽  
Start Up ◽  
Reverse Flow Reactor

Modeling and simulation of reverse flow reactor for the catalytic oxidation of methane: the development of start-up operating procedures In this modelling and simulation study, three operating procedures during start-up of lean methane (1%-v) oxidation in reverse flow reactor (RFR) have been investigated to get auto-thermal condition, high methane conversion, faster pseudo steady state, and low preheating energy requirement. The RFR model developed based on one-dimension pseudo-homogeneous model for mass balance and heterogeneous model for energy balance. Procedure 1 , the preheating was employed only on the catalyst zone, fails to conduct the auto-thermal reaction and to achieve high conversion. Procedure 2, the preheating was employed for inert and catalyst of left side only, able to achieve the auto-thermal up to switching time (ST) 230 s. Procedure 3, the preheating was employed along the reactor bed, achieve the auto-thermal condition up to ST 300 s. Procedure 2 and 3 achieved the pseudosteadystate at 1000 s for ST 200 s with total conversion during start-up are 95% and 99%. The conversion of Procedure 3 higher than Procedure 2, unfortunately the heat load of Procedure 3 two times higher than Procedure 2. Keywords: modelling and simulation, catalytic methane oxidation, start-up procedure, reverse flow reactor, switching timeAbstrakDi dalam studi pemodelan dan simulasi ini, berbagai prosedur operasi reverse flow reactor (RFR) selama start-up untuk oksidasi katalitik metana encer (1%-v) dikaji dengan target sistem beroperasi secara ototermal, konversi metana tinggi, waktu pencapaian kondisi tunak semu (pseudosteady state) cepat, dan beban panas rendah. Pemodelan reaktor didasarkan pada model satu dimensi dan pseudohomogeneous untuk neraca massa, serta heterogen untuk neraca energi. Pemanasan katalis saja pada awal reaksi (Prosedur 1) tidak dapat mencapai kondisi reaktor yang ototermal. Pemanasan katalis dan inert bagian kiri (Prosedur 2) mampu mencapai kondisi reaktor yang ototermal hingga switching time (ST) 230 detik. Pemanasan seluruh bagian reaktor pada awal reaksi (Prosedur 3) mampu mencapai kondisi reaktor yang ototermal pada ST paling lama 300 detik. Prosedur start-up 2 dan 3 untuk ST 200 detik sama-sama mencapai waktu pseudosteady state pada 1000 detik dengan konversi total selama start-up masing-masing 95% dan 99%. Meskipun Prosedur 3 memberikan konversi sedikit lebih tinggi daripada Prosedur 2, namun beban panas Prosedur 3 mencapai dua kali lebih besar daripada Prosedur 2.Kata kunci: emisi metana, pemodelan dan simulasi, prosedur start-up, reverse flow reactor, switching time.

scholarly journals SOLUTION OF THE REVERSE FLOW REACTOR MODEL USING HOMOTOPY ANALYSIS METHOD

2020 ◽  
Vol 22 (1) ◽  
pp. 129-137
Author(s):  
Suharsono Suharsono ◽  
Sri Wulandari ◽  
Aang Nuryaman ◽  
Mustofa Usman ◽  
Wamiliana Wamiliana ◽  
...  
Keyword(s):  
Homotopy Analysis Method ◽  
Flow Reactor ◽  
Reverse Flow ◽  
Homogeneous Model ◽  
Analysis Method ◽  
Reactor Model ◽  
Conversion Of Methane ◽  
Homotopy Analysis ◽  
Reverse Flow Reactor ◽  
Carbon Dioxide Co2

Methane (CH4) is one of the most dangerous greenhouse gases in the atmosphere. A reverse flow reactor is utilized to convert CH4 to carbon dioxide (CO2) as a means of reducing the effect of global warming. The dynamics of its dependent variables can be stated by a set of convective-diffusion equations. In this article, we examined analytical solutions of temperature dynamics and methane conversion for a 1-D pseudo homogeneous model without refrigeration by using the homotopy analysis method. The results show that temperature and conversion of methane will go to constant when time goes to infinity. ABSTRAK: Metana (CH4) merupakan salah satu gas rumah hijau paling berbahaya di atmosfera. Reaktor aliran balik telah dipakai bagi menukar CH4 kepada CO2 bagi mengurangkan kesan pemanasan global. Dinamik pemboleh ubah bersandar ini dapat diterangkan melalui satu set persamaan konvektif-difusi. Artikel ini akan mengkaji penyelesaian analisis dinamik suhu dan penukaran metana bagi model 1-D pseudo-homogen tanpa penyejukan dengan menggunakan kaedah analisis homotopi. Hasil kajian menunjukkan bahawa suhu dan penukaran metana akan berterusan dengan masa tak terhingga.

scholarly journals Dinamika Reaktor Katalitik Aliran Bolak-Balik untuk Oksidasi Emisi Gas Metana

2020 ◽  
Vol 8 (2) ◽  
pp. 93-100
Author(s):  
Yogi Wibisono Budhi ◽  
Hans Gunawan Rimbuala ◽  
Andhika Feri Wibisono
Keyword(s):  
Flow Reactor ◽  
Switching Time ◽  
Reverse Flow ◽  
Flow Direction ◽  
Operating Mode ◽  
Heat Propagation ◽  
Switching Times ◽  
Reactor Dynamics ◽  
Reaction Conversion ◽  
Reverse Flow Reactor

The performance of a reverse flow reactor (RFR) is strongly influenced by the switching time used to alternate the flow direction. This research aimed to study the effect of the switching time on reactor dynamics including the heat propagation along the bed and reaction rate in the oxidation methane for low concentration using catalytic reverse flow reactor. The experimental results show that the reverse flow operating mode can influence heat propagation along the reactor and reaction conversion. Based on the three switching times was tested, the temperature dynamics formed were in the sliding regime. The effect of switching time on RFR on conversion is very significant. When compared to steady operation, RFR operation provides the highest conversion at smaller switching times. At large switching times, the effect of reversal of flow direction becomes less dominant and reactor behavior approaches steady state.

scholarly journals Metode operasi reverse flow reactor dengan umpan fluktuatif dalam pengolahan emisi gas metana di stasiun kompresor

2018 ◽  
Vol 8 (3) ◽  
pp. 74
Author(s):  
M. Effendy ◽  
Yogi Wibisono Budhi ◽  
Yazid Bindar ◽  
S Subagjo
Keyword(s):  
Global Warming ◽  
Modeling And Simulation ◽  
Flow Reactor ◽  
Switching Time ◽  
Reverse Flow ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Operation Procedure ◽  
Reverse Flow Reactor ◽  
The Impact

Operation method of reverse flow reactor with fluctuating feed for methane gas emmision processing in compressor station.The leak of CH4 from the compressor stations can not be avoided and it may cause the global warming. The impact of the global warming can be reduced by oxidizing CH4 into CO2. The CH4 capture strategy using the exhaust mounted on the top of the building causes (1) CH4 levels detected in the gas mixture is very small (±1% volume), (2) the feed gas temperature is near the ambient temperature (±30 oC), (3) the CH4 concentration fluctuates over time. The reverse flow reactor (RFR) is a fixed bed reactor, which has the ability to abate the leak of CH4 and has the ability to act as an autothermal reactor. The purpose of this research is to find a proper operation procedure of the fixed bed reactor for the oxidation of lean methane emission via modeling and simulation. The reactor model is based on the continuity equation and the heat balance, while the concentration of the feed gas behavior dynamic and modeled as a step function. The model was solved numerically using the software package FlexPDE version 6. At ST (switching time) 50 seconds, the RFR operates autothermally with heat accumulation in the inert section fluctuating between 12.4 to 14.2 kJ. At ST 100 seconds, the heat trap inside the reactor increases monotonically. The use of ST 100 seconds requires an additional operation procedure to keep the reactor safe.Keywords: Global warming, concentration dynamic, autothermal operation, modeling and simulation, reverse flow reactor. AbstrakKebocoran gas CH4 dari stasiun kompresor tidak dapat dihindarkan dan ini merupakan salah satu sumber penyebab pemanasan global. Dampak pemanasan global ini dapat dikurangi dengan mengoksidasi gas CH4 menjadi gas CO2. Strategi penangkapan gas CH4 menggunakan exhaust yang terpasang pada bagian atas gedung menyebabkan (1) kadar CH4 yang terdeteksi dalam campuran gas cukup kecil (±1% volume), (2) temperatur gas umpan mendekati temperatur ruangan (± 30 oC), (3) konsentrasi gas CH4 akan berperilaku dinamik. Reverse flow reactor (RFR) mempunyai kemampuan untuk mengatasi akibat yang ditimbulkan oleh proses penangkapan gas CH4 di stasiun kompresor dan mempunyai kemampuan secara ototermal. Tujuan penelitian ini adalah mendapatkan metode operasi yang tepat untuk mengatasi gas umpan yang berperilaku dinamik. Model yang dikembangkan mengacu pada persamaan kontinuitas dan konsentrasi gas umpan yang berperilaku dinamik dimodelkan sebagai fungsi step. Model diselesaikan menggunakan software FlexPDE versi 6. Penggunaan switching time (ST) yang tepat dapat mengatasi permasalahan konsentrasi gas umpan yang berperilaku dinamik. Pada ST 50 detik, RFR mampu bekerja secara ototermal dengan nilai akumulasi panas di bagian inert yang berfluktuasi antara 12,4–14,2 kJ. Pada ST 100 detik, panas yang terjebak di dalam reaktor semakin lama semakin meningkat. Penggunaan ST 100 detik memerlukan prosedur operasi tambahan untuk menjaga reaktor agar tidak meleleh dan menjaga reaktor tetap beroperasi secara ototermal. Kata Kunci: Pemanasan global, dinamika konsentrasi, operasi ototermal, pemodelan dan simulasi, reaktor aliran bolak-balik.

scholarly journals TOWARDS KINETIC REGIME OF REVERSE FLOW OPERATION

2018 ◽  
Vol 4 (3) ◽  
pp. 322
Author(s):  
Yogi Budhi
Keyword(s):  
Steady State ◽  
Flow Reactor ◽  
Switching Time ◽  
Reverse Flow ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Kinetic Regime ◽  
Steady State Operation ◽  
Reverse Flow Reactor

An analysis of reverse flow operation and its experimental study for ammonia oxidation to produce either N2, N2O, and NO have been carried out. An experimental set-up of reverse flow reactor was constructed for a laboratory scale. The experiment under steady state operation was performed as a base case in order to judge the potential during the reverse flow operation. Aim was to investigate the behavior of reverse flow operation and to observe the reactor performance. Focus was on the comparison of the steady state and reverse flow operations. The experiments show that the behavior of reverse flow reactor is strongly influenced by the ratio of the switching time over the residence time. The ammonia conversion during the regular reverse flow operation shows lower values compared to the steady state operation which is even worse during asymmetric mode. The product distributions may change under flow reversal, depending on the operating conditions, regime of operation, and operation mode.Keywords : Reverse Flow Operation, Fixed Bed Reactor, Selectivity Manipulation, Steady State Operation, Ammonia OxidationAbstrak Sebuah analisis operasi aliran bolak-balik dan studi eksperimental oksidasi amoniak untuk menghasilkan baik N2., N2O, dan NO telah dilakukan. Sebuah perangkat eksperimen reaktor aliran bolak-balik dikonstruksi untuk skala laboratorium. Eksperimen dalam operasi keadaan tunak dilakukan sebagai kasus dasar untuk menilai potensi operasi aliran bolak-balik. Tujuan penelitian ini adalah untuk meneliti kelakuan operasi aliran bolak-balik dan untuk mengamati kinerja reaktor. Kajian ini dititikberatkan pada perbandingan operasi keadaan tunak dan operasi aliran bolak-balik. Hasil percobaan menunjukkan bahwa kelakuan reaktor aliran bolak-balik sangat dipengaruhi oleh nisbah waktu pembalikan arah aliran (switching time) terhadap waktu tinggal. Konversi amomiak dalam operasi aliran bolak-balik menunjukkan nilai yang lebih rendah dibandingkan dengan operasi keadaan tunak dan dalam mode asimetrik konversinya bahkan lebih rendah lagi. Distribusi produk dapat berubah dalam pembalikan aliran yang bergantung pada kondisi-kondisi operasi, daerah operasi, dan mode operasi.Kata Kunci : Operasi Aliran Bolak-balik, Reaktor Fixed Bed, Manipulasi Selektivitas, Operasi Tunak, Oksidasi Amoniak

scholarly journals Kajian pemanfaatan reverse flow reactor untuk oksidasi katalitik uap bensin

2018 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
Profiyanti Hermien Suharti ◽  
Yogi Wibisono Budhi ◽  
Yazid Bindar
Keyword(s):  
Catalytic Oxidation ◽  
Flow Reactor ◽  
Reverse Flow ◽  
Operation Mode ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Heat Of Reaction ◽  
Gasoline Vapor ◽  
Start Up ◽  
Reverse Flow Reactor

Study of utilization of reverse flow reactor for the catalytic oxidation of gasoline vapor Catalytic oxidation of gasoline vapor is one of methods to reduce the gasoline vapor emission at fuel station. This reaction is exothermic with large heat of reaction, so that the heat released can be used for heating the feed gas, leading to auto thermal condition.. The auto thermal conditions with low feed concentration, like gasoline vapor emission, can be achieved by using a reverse-flow reactor (RFR), a kind of fixed bed reactor in which flow direction is periodically changed. The objective of this research is to develop the using of a RFR to reduce the gasoline vapor emissions at fuel station, based on simulations using FlexPDE version 6 and later used as the basis for the experimental development. The model of RFR was developed, by using iso-octane as a model component. The simulation consists of: (1) RFR with one way direction, which was used as the basis for the determination of RFR operating conditions and (2) RFR at current start-up conditions. The simulations were conducted using a software package FlexPDE version 6. The kinetic parameters and physical properties were taken from literature. The simulation results of the RFR at one way direction show that catalytic oxidation of gasoline vapor can conducted best at temperature of 773 K, while the RFR shows the accumulation of heat in the reactor bed that can be utilized for process start-up. Time to reach 100% conversion of gasoline for reverse flow operation mode is faster than one way operation mode. Thus the operation of gasoline emission catalytic oxidation reaction in reverse flow reactor can be developed experimentally. Keywords: Dynamic reactor, Catalytic oxidationAbstrakOksidasi katalitik uap bensin adalah salah satu cara untuk mengurangi emisi uap bensin di stasiun pengisian bahan bakar umum. Reaksi ini adalah reaksi eksotermik, sehingga panas reaksi yang timbul dapat dimanfaatkan untuk memanaskan umpan agar reaktor dapat berperilaku ototermal. Kondisi ototermal dengan umpan emisi uap bensin yang berkonsentrasi rendah dapat tercapai dengan menggunakan reverse flow reactor (RFR), yaitu reaktor unggun tetap yang arah alirannya diubah secara periodik. Tujuan kajian ini adalah untuk mengkaji pemanfaatan RFR untuk menurunkan emisi uap bensin di SPBU, berdasarkan simulasi menggunakan FlexPDE versi 6 dan nantinya digunakan sebagai dasar pengembangan secara eksperimental. Model RFR dikembangkan dengan menggunakan iso-oktana sebagai komponen model. Simulasi terdiri dari (1) simulasi RFR satu arah, yang digunakan sebagai dasar penentuan kondisi operasi RFR dan (2) simulasi RFR dengan konfigurasi start-up tertentu. Parameter kinetika dan sifat–sifat fisik yang diperlukan diambil dari literatur. Hasil simulasi RFR satu arah menunjukkan bahwa reaksi oksidasi katalitik uap bensin dapat terselenggara dengan baik pada suhu 773 K, sedangkan simulasi RFR kondisi aliran bolak-balik menunjukkan adanya akumulasi panas di unggun reaktor yang dapat dimanfaatkan saat proses start-up. Waktu untuk mencapai konversi 100% untuk simulasi mode operasi bolak-balik lebih cepat daripada mode operasi satu arah. Dengan demikian penyelenggaraan reaksi oksidasi katalitik emis uap bensin di reverse flow reactor secara eksperimental dapat dikembangkan.Kata Kunci: Reaktor dinamik, Oksidasi katalitik

Hybrid modeling and dynamics of a controlled reverse flow reactor

AIChE Journal ◽  
2007 ◽  
Vol 53 (8) ◽  
pp. 2084-2096 ◽  
Author(s):  
Erasmo Mancusi ◽  
Lucia Russo ◽  
Antonio Brasiello ◽  
Silvestro Crescitelli ◽  
Mario di Bernardo
Keyword(s):  
Flow Reactor ◽  
Reverse Flow ◽  
Hybrid Modeling ◽  
Reverse Flow Reactor
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