Inlet Gas Temperature Research Articles

On the effects of fuel type, fuel mixing and sulphur content on the performance of a high-temperature membrane reactor adapting liquid fuel: A numerical study

Abstract The study investigates numerically oxygen permeation and combustion and emission characteristics of a button-cell high-temperature membrane reactor (HTMR) handling different grades of liquid fuels including methanol (CH3OH), ethanol (C2H5OH), benzene (C6H6), n-octane (C8H18) and gas oil (C16H29). Effects of mixing different grades of fuels on the HTMR performance are also investigated. A disc-shaped La2NiO4 (LNO) ceramic membrane is used. A plain orifice atomization model is used for numerical calculations of liquid fuel atomization. Fuel is introduced along with CO2 at sweep inlet and air is introduced at fed inlet of the membrane reactor. 2-D axisymmetric mesh was constructed, and simulations were performed using Ansys-Fluent Workbench 15.0. All calculations were performed at fixed inlet gas temperature of 1173 K, fixed inlet fuel temperature of 300 K and fixed molar fuel concentration of 5% in the vapor phase. For single fuel operation, the highly reactive light oxygenated alcohol fuels resulted in stoichiometric combustion with better oxygen flux compared to rich combustion and low oxygen flux for heavier fuels. Gas oil fuel showed poor fuel evaporation, poor mixing with the sweeping gas, and low reaction rate. Trying to improve the performance of the HTMR while burning heavy fuels, three mixtures of three fuels containing gas oil fuel were tested. The compositions of the mixtures 1, 2 and 3 are 2%C6H6/2%C8H18/1% C16H29, 2%CH3OH/2%C8H18/1%C16H29 and 2%CH3OH/2%C6H6/1%C16H29. The results showed better performance of the HTMR when burning gas oil fuel in a mixture than burning it purely. Mixtures 1 and 2 resulted in about three times and mixture 3 resulted in about six times the oxygen flux value when using pure gas oil fuel. The maximum temperature with the reactor has been improved from 1208 K for gas oil fuel to 1383 K, 1372 K and 1557 K for mixtures 1, 2 and 3. Using methanol as fuel additive significantly improve the performance of the HTMR, even better than burning it alone, and enables the use of heavier fuels in HTMR applications. Based on that, the performance of the HTMR was evaluated while burning mixtures of two fuels, one of them is methanol. Three mixtures were considered (mixtures 4, 5 and 6) with the compositions of 4%CH3OH/1%C6H6, 4%CH3OH/1%C8H18 and 4%CH3OH/1%C16H29. Mixing methanol with benzene (mixture 4) resulted in the highest obtained oxygen permeation flux among the tested ranges of pure and mixed fuels. Locations where sulfates compounds are created within the HTMR with respect to the membrane are calculated for proper control of membrane operation while utilizing heavy gas oil fuel with Sulphur content.

Entropy Generation Minimization for Reverse Water Gas Shift (RWGS) Reactors.

Thermal design and optimization for reverse water gas shift (RWGS) reactors is particularly important to fuel synthesis in naval or commercial scenarios. The RWGS reactor with irreversibilities of heat transfer, chemical reaction and viscous flow is studied based on finite time thermodynamics or entropy generation minimization theory in this paper. The total entropy generation rate (EGR) in the RWGS reactor with different boundary conditions is minimized subject to specific feed compositions and chemical conversion using optimal control theory, and the optimal configurations obtained are compared with three reference reactors with linear, constant reservoir temperature and constant heat flux operations, which are commonly used in engineering. The results show that a drastic EGR reduction of up to 23% can be achieved by optimizing the reservoir temperature profile, the inlet temperature of feed gas and the reactor length simultaneously, compared to that of the reference reactor with the linear reservoir temperature. These optimization efforts are mainly achieved by reducing the irreversibility of heat transfer. Optimal paths have subsections of relatively constant thermal force, chemical force and local EGR. A conceptual optimal design of sandwich structure for the compact modular reactor is proposed, without elaborate control tools or excessive interstage equipment. The results can provide guidelines for designing industrial RWGS reactors in naval or commercial scenarios.

The effect of engine operating conditions on exhaust gas recirculation cooler fouling

Exhaust gas recirculation (EGR) cooler fouling occurs when particulate matter (PM) and hydrocarbons (HC) in diesel exhaust form a deposit on the walls of the EGR cooler through thermophoresis and condensation. To better understand the mechanisms controlling deposit formation and removal and how operating conditions can affect cooler performance, 20 identical tube-in-shell EGR coolers with sinusoidal fins were fouled using a 5-factor, 3-level experimental design. The deposit thickness was measured using two methods: (1) epoxy-mounting and polishing cooler cross-sections and comparing deposit thicknesses on the primary (outer tube) to the secondary (fins) heat transfer surfaces, and (2) milling tube sections such that the surface of a fin could be observed and measuring the deposit thickness across the fin using a 3D profilometer. Near the cooler inlet, high inlet gas temperatures reduced deposit thickness by promoting mud-cracking and spallation. Near the middle of the cooler, the flow rate had the largest impact on the deposit thickness through the effect on residence time of the PM. The HC concentration along with flow rate had the largest effects near the cooler outlet where the lower temperatures allows for more HC condensation. These insights into how engine operating conditions influence the development of fouling layers in EGR coolers learned through this study will aid in the development of more fouling resistant coolers in the future.

Numerical analysis of energy separation in Ranque-Hilsch vortex tube with gaseous hydrogen using real gas model

Ranque-Hilsch vortex tube (RHVT) is a simple device with energy separation effect. It has potential to precool gaseous hydrogen in the multi-stage liquefaction process in situations where a device of high reliability is required or high-pressure gas is readily available. In the present work, CFD analysis using the real gas model has been carried out to investigate energy separation performance in RHVT with gaseous hydrogen from cryogenic temperature to ambient temperature. The predicted temperature separation at both cold and hot exits are found to satisfactorily accord with the experimental data from literature. Streamline structure at cryogenic inlet temperature is carefully compared with that at ambient temperature. Accordingly, energy separation mechanism is concluded from two kinds of streamline structures existing in RHVT with inlet gas temperature ranging from 50 K to 294 K. Additionally, the influences of inlet temperature and mass flow rates on energy separation are investigated. To find a more accurate measurement criteria of energy separation in RVHT, the specific cooling power separation is defined to evaluate the cooling capacity of instead of cold exit temperature alone.

Classification by Artificial Neural Network according to the values affecting Electricity Generation

Predicting the amount of electricity produced in a power plant is very important for today’s economy. Oven Power (MW), Boiler Input Gas Temperature, Superheated Steam Amount, ID-Fan Speed, Feeding Water Tank data affect the electricity production. In this article, Etikrom A.Ş. The electricity production amount to be produced in Elazığ Etikrom A.Ş. was estimated by using the data of Oven Power (MW), Water Inlet Gas Temperature, Steam Vapor Volume, ID-Fan Speed, Feeding Water Tank data. Electricity generation amount is used as verification data. That is, by the k-means clustering method, the electricity generation amount is divided into 3 classes (low, medium, and high). 3621 data including Oven Power (MW), Boiler Input Gas Temperature, Superheated Steam Amount, ID-Fan Speed, and Feeding Water Tank data were used after class 3 separation. With the K-means clustering method, 2742 of these data were clustered as low electricity, 296 as medium electricity and 583 as high electricity. This clustered data was given to the Artifical Neural Network classifier. The success rate obtained as a result of this classification is 85.81%. Classified data were analyzed by ROC curve.

Classification by Artificial Neural Network according to the values affecting Electricity Generation

Predicting the amount of electricity produced in a power plant is very important for today’s economy. Oven Power (MW), Boiler Input Gas Temperature, Superheated Steam Amount, ID-Fan Speed, Feeding Water Tank data affect the electricity production. In this article, Etikrom A.Ş. The electricity production amount to be produced in Elazig Etikrom A.Ş. was estimated by using the data of Oven Power (MW), Water Inlet Gas Temperature, Steam Vapor Volume, ID-Fan Speed, Feeding Water Tank data.

Heat Transfer and Entropy Generation Analysis of an Intermediate Heat Exchanger in ADS

The intermediate heat exchanger for enhancement heat transfer is the important equipment in the usage of nuclear energy. In the present work, heat transfer and entropy generation of an intermediate heat exchanger (IHX) in the accelerator driven subcritical system (ADS) are investigated experimentally. The variation of entropy generation number with performance parameters of the IHX is analyzed, and effects of inlet conditions of the IHX on entropy generation number and heat transfer are discussed. Compared with the results at two working conditions of the constant mass flow rates of liquid lead-bismuth eutectic (LBE) and helium gas, the total pumping power all tends to reduce with the decreasing entropy generation number, but the variations of the effectiveness, number of transfer units and thermal capacity rate ratio are inconsistent, and need to analyze respectively. With the increasing inlet mass flow rate or LBE inlet temperature, the entropy generation number increases and the heat transfer is enhanced, while the opposite trend occurs with the increasing helium gas inlet temperature. The further study is necessary for obtaining the optimized operation parameters of the IHX to minimize entropy generation and enhance heat transfer.

Absorption of CO2 from modified flue gases of power generation Tarahan chemically using NaOH and Na2CO3 and biologically using microalgae

This research was carried out on the absorption of CO2 from the modified flue gases of power generation Tarahan using NaOH (sodium hydroxide) and Na2CO3 (sodium carbonate). The operation was conducted in a packed column absorber and then the output gases from the packed column was fed into photo-bioreactor for biological absorption. In the photo-bioreactor, two species of microalgae, N. occulata and T. chuii, were cultivated to both absorb CO2 gas and to produce biomass for algal oil. The aims of this research were, first, to determine the effect of absorbent flow rate on the reduction of CO2 and on the decrease of output gas temperature, second, to determine the characteristics of methyl ester obtained from biological absorption process. Flow rates of the absorbent were varied as 1, 2, and 3 l/min. The concentrations of NaOH and Na2CO3 were 1 M at a constant gas flow rate of 6 l/min. The output concentrations of CO2 from the absorber was analyzed using Gas Chromatography 2014-AT SHIMADZU Corp 08128. The results show that both of the absorbents give different trends. From the absorption using NaOH, it can be concluded that the higher the flow rate, the higher the absorption rate obtained. The highest flow rate achieved maximum absorption of 100%. On the other hand, absorption with Na2CO3 revealed the opposite trend where the higher the flow rates the lower the absorption rate. The highest absorption using Na2CO3 was obtained with the lowest flow rate, 1 l/min, that was 45,5%. As the effect of flow rate on output gas temperature, the temperature decreased with increasing flow rates for both absorbents. The output gas temperature for NaOH and Na2CO3 were consecutively 35 °C and 31 °C with inlet gas temperature of 50°C. Absorption of CO2 biologically resulted a reduction of CO2 up to 60% from the input gas concentration. Algal oil was extracted with mixed hexane and chloroform to obtain algal oil. Extracted oil was transesterified to methyl ester using sodium hydroxide as a catalyst. The results of in-situ transesterification method cannot be identified. Both microalgae achieved maximum yield at 2% catalyst concentration. Nannochloropsis occulata achieved the highest yield of algal oil that is 88.5%. The highest content of methyl ester from Nannochloropsis occulata was undecanoic acid methyl ester by 55.42% and the result from Tetraselmis chuii was palmitic acid methyl ester by 81.58%.

Improvement of cement plant dust emission by bag filter system

The limestone quarry in PT Indocement Tunggal Prakarsa (ITP) in Cirebon is considered as a complex quarry in terms of chemical composition and material hardness. From the beginning of the plant operation up to the end of 2015, the dust removal was rely on electrostatic precipitator (EP) system. Whenever limestone from specific quarry zones were incorporated into Raw Mill (RM) feed or there was an upset condition, the dust emission increased significantly. Beside higher demand of electricity, an EP system requires lower gas inlet temperature in order to remove the dust effectively which requires larger cooling water in the previous gas conditioning tower to cool down gas from 400 °C to about 100 °C. By considering the drawbacks, the EP system was replaced by a bag filter (BF) system. The BF allows higher temperature of gas inlet and it has higher dust removal efficiency. In this study, the efficiency of the two different dust removal systems is compared. The effect of process variables i.e. RM feed, kiln feed, inlet temperature and pressure, and small size particle fraction to the dust emission are studied by multivariate linier regression analysis. It is observed that the BF system can reduce significantly the dust emission from 30 to 6 mg/m3 and in the same time reducing CO2 emission by 0.24 ton/year from the electricity consumption saving.

Energy conversion and temperature dependence in ozone generator fed by synthetic air

ABSTRACTA homogenous chemical kinetic model consisting of 21 species and 118 reactions is applied to investigate energy conversion and its temperature dependence in ozone generator fed by synthetic air. The portion of electric energy converted into reaction heat, gas heating and heat loss to surroundings (by convection) in terms of the total electric energy input, the conversion ratios ηreaction, ηgas, and ηloss, are obtained. The detailed reaction pathway including the degree of transformation among species for ozone production is also obtained via simulation of the reaction kinetics. In addition, sensitivity analysis and rate-of-production analysis for the three foremost species O3, O, and N2(A) are performed to understand quantitatively the temperature dependence of sensitivity coefficient and production rate for each individual reaction. ηreaction shows a steep rise at low specific energy, but then suffers a gradual decrease at high specific energy. ηloss has a contrary behavior. And ηgas increases steadily with the increase of specific energy. The ηreaction peak of 35.1% is achieved at specific energy of 0.17 J/cm3 at the conditions under investigation. Additionally, inlet gas temperature only has a small effect on energy conversion. Moreover, high gas temperature in discharge gap is confirmed to be not favorable for ozone formation from the view of reaction heat. The sensitivity coefficients of reactions with electron participation are sensitive to gas temperature. O+O2+O2→O2+O3 and O+O2+N2→N2+O3 account for about 70% and 30% of generated ozone respectively at the given conditions. And e+O2→e+O+O, N2(A)+O2→N2O+O, and N2(A)+O2→O+O+N2 are responsible for about 51.3%, 14.7%, and 32.0% of oxygen atom, respectively.

CO2 Capture and Crystallization of Ammonia Bicarbonate in a Lab-Scale Scrubber

A lab-scale bubble-column scrubber is used to capture CO2 gas and produce ammonia bicarbonate (ABC) using aqueous ammonia as an absorbent under a constant pH and temperature. The CO2 concentration is adjusted by mixing N2 and CO2 in the range of 15–60 vol % at 55 °C. The process variables are the pH of the solution, temperature, gas-flow rate and the concentration of gas. The effects of the process variables on the removal efficiency (E), absorption rate (RA) and overall mass-transfer coefficient (KGa) were explored. A multiple-tube mass balance model was used to determine RA and KGa, in which RA and KGa were in the range of 2.14 × 10−4–1.09 × 10−3 mol/(s·L) and 0.0136–0.5669 1/s, respectively. Results found that, RA showed an obvious increase with the increase in pH, inlet gas concentration and gas temperature, while KGa decreased with an increase in inlet gas concentration. Using linear regression, an empirical expression for KGa/E was obtained. On the other hand, ammonia bicarbonate crystals could be produced at a pH of 9.5 when the gas concentration was higher than 30% and γ (=Fg/FA, the gas-liquid molar flow rate ratio) ≥ 1.5.

Numerical Simulations of a 96-rod Polysilicon CVD Reactor

With the rapid development of the photovoltaic industry, pressurized Siemens belljar-type polysilicon CVD reactors have been enlarged from 24 rods to 96 rods in less than 10 years aimed at much greater single-reactor productivity. A CFD model of an industry-scale 96-rod CVD reactor was established to study the internal temperature distribution and the flow field of the reactor. Numerical simulations were carried out and compared with actual growth results from a real CVD reactor. Factors affecting polysilicon depositions such as inlet gas injections, flow field, and temperature distribution in the CVD reactor are studied.

Heat Transfer Enhancement by Vortex Generators for Compact Heat Exchanger of Automobiles

The paper describes the effects of heat transfer enhancement and gas-flow characteristics by wing-type-vortex-generators inside a rectangular gas-flow duct of a plate-fin structure exhaust gas recirculation (EGR) cooler used in a cooled-EGR system. The analyses are conducted using computational fluid dynamics (CFD). The numerical modelling is designed as a gas-flow rectangular duct of an EGR cooler using two fluids with high temperature gas and coolant water whose flow directions are opposite. The gas-flow duct used to separate two fluids is assembled with a stainless steel material. The inlet temperature and velocity of gas flowed inside gas-flow duct are 400°C and 30 m/s, respectively. Coolant water is flowed into two ducts on both a top and a bottom surface of the gas-flow duct, and the inlet temperature and velocity is 80°C and 0.6 m/s, respectively. Wing-type-vortex-generators are designed to achieve good cooling performance and low pressure drop and positioned at the center of the gas-flow duct with angle of inclination from 30 to 150 degrees at every 15 degrees. The temperature distributions and velocity vectors gained from numerical results were compared, and discussed. As a result, it is found that the vortices guided in the proximity of heat transfer surfaces play an important role in the heat transfer enhancement and low pressure drop. The collapse of the vortices is caused by complicated flow induced in the corner constituted by two surfaces inside gas-flow duct.

Computational fluid dynamics simulation of heat transfer performance of exhaust gas re-circulation coolers for heavy-duty diesel engines

In order to estimate the performance of exhaust gas re-circulation coolers two factors were considered: the cooling efficiency and pressure drop. For that, three models of exhaust gas re-circulation coolers intended to heavy-duty Diesel engines were chosen and studied by numerical simulations. The CFD software FLUENT was used to solve the governing equations. Temperature dependant physical properties of the recycled exhaust gas were incorporated via the “User Defined Functions” feature of FLUENT. The inlet temperature of the exhaust gas is set to 523.15 K and the inlet mass-flow rate changes from 0.07 up to 0.2 kg/s. The computed performance results were compared to existing experimental measurements. The comparison of the computed results for the three models allowed to distinguish the exhaust gas re-circulation cooler model consisting of 19 tubes with helical baffles as having the best performance in terms of cooling efficiency and pressure drop.

Experimental Investigation of Thermal Cracking and Permeability Evolution of Granite with Varying Initial Damage under High Temperature and Triaxial Compression

Thermal cracking and permeability evolution of granite under high temperature and triaxial compression are the key to designing high‐level waste disposal sites. In this paper, uniaxial compression tests of granite specimens with different axial compression are designed, and then a solid‐head‐designed coupling triaxial testing system is applied to study thermal cracking and permeability evolution of granite specimen with different damage at different inlet gas pressures (1, 2, 4, and 6 MPa) and temperatures (ranging from 100 to 650°C). The test results show that granite, nearly impermeable rocks, can show a striking increase of permeability by heating beyond the critical temperature. When the initial axial pressure is 60% or 70% of the uniaxial compressive strength, the growth of granite permeability exhibits three stages during 100∼650°C heating process. Permeability increases by two orders of magnitude, but it does not reach the maximum value (i.e., a network of interconnected cracks is not fully formed in the specimen). With increasing initial damage, permeability shows a sharp increase. Permeability increases by three orders of magnitude, it is in equilibrium state, and a network of interconnected cracks is fully formed in the specimen. Permeability of granite has a critical temperature at which permeability increases sharply. When the temperature is lower than the critical temperature, the magnitude of permeability is 10−18 m2 with a slight increase. When temperature is higher than the critical temperature, the magnitude of permeability is 10−15 m2 with a sharp increase. The critical temperature is related to the initial damage of specimen, and the critical temperature is smaller with the initial damage going larger. Therefore, studying thermal cracking and permeability evolution of granite with different initial damage under high temperature and triaxial compression is expected to provide necessary and valuable insight into the design and construction of high‐level waste disposal structures.

Waste heat availability in the raw meal department of a cement plant

The main aim of this study was to determine the available heat in the cement kiln exhaust gas subject to different process conditions. A Norwegian cement plant producing about 1.3 million tons of cement per year was used as a case study. A mass and energy balance was made for the raw meal department, and process data available from the plant process database as well as manually measured gas flow rates were used to calculate the available heat. The available heat can be utilized by a combination of low pressure (LP) steam generation and hot water generation. It was found that waste heat is 1.5–4.2MW for LP steam generation and 2.2–5.8MW for hot water generation. The variation in available heat is due to different raw meal types being produced, requiring different gas inlet temperatures to raw meal mill. In cases when no raw meal is produced (in maintenance shutdown periods), all the gas will bypass the mill, and approximately 20MW of LP steam and 6MW of hot water can be generated. The heat loss from the system was estimated based on measurements, and the fan power inputs were calculated. Both were found to be negligible compared to the available heat. Furthermore, the total false air coming into the system was estimated as 40–50% of the total gas flow rate going out from the raw meal department.

Thermodynamic Calculation and Optimization of Thermal Power Boiler Based on Flexible Equilibrium Analysis Method

In order to study thermal calculation and optimization scheme of thermal power boiler, through the flexible use of equilibrium analysis method, the practical problems brought about by too high exhaust gas temperature of thermal power boiler are studied. Through the thermodynamic calculation, the thermal calculation simulation is carried out under 95%, 85%, and 60% three kinds of operational loads for boiler after after low temperature reheater retrofit optimization and heating surface increase. In addition, it is compared with the calculation parameters under the corresponding condition before the transformation. The results show that the increase of low temperature reheater area can increase the low temperature reheater heat absorption, and make the reheat steam humidity improved significantly. At the same time, the flue gas baffle is adjusted and the gas ratio on the side of overheating is increased. As a result, we can effectively alleviate the serious uneven reheat and super-heat side baffle opening for a long time. However, low temperature reheater outlet flue gas temperature and economizer inlet gas temperature can be significantly reduced because of the transformation and optimization of low humidity reheater. It is conclude that the final temperature of flue gas has not been significantly reduced, which only completed part of requirement for the exhaust gas temperature reduction.

Optimum operating conditions for improving natural gas dew point and condensate throughput

Natural gas dew point temperature is a vital quality parameter. The effective control of this specification is important if the natural gas integrity and quality are to be maintained. The present work focuses on improving the dew point and condensation production rate of south Dabaa field dew point control unit (DPCU) located in the Egyptian western desert and owned to the South Dabaa Petroleum Company. Influence of the operational variables on outlet gas dew point and produced condensate were investigated. The simulation results illustrated that feed gas inlet temperature, composition and flow rate, Joule Thomson (JT) valve downstream, and upstream pressure and hot bypass flow rate have a great effect on the sales gas dew point as well as the condensate throughput. A field experiments were conducted to validate the simulation results. It is noticed that there is a good agreement between simulation and experimental results, considering the outlet gas dew point at different operating conditions. Lingo optimization software was used to find the plant optimum conditions. Two quadratic equations were developed based on regression analysis for calculating the dew point and plant condensate rate at any operational variables. The impact of replacing the existing JT valve by a turbo expander was studied. The simulation results indicate that the turbo expander is more effective in comparison with JT valve refrigeration system in decreasing the sales gas dew point and increasing the condensate production rate.

Catalytic combustion of vineyard pruning waste in a conical spouted bed combustor

The feasibility of a conical spouted bed combustor for the thermal catalytic exploitation of vineyard pruning waste, under different operating conditions has been analyzed. Stable-flow regimes of vine shoot beds with a Pd catalyst were determined over a wide range of combustion conditions. With the aim of improving the combustion yield, thermal exploitation of vine shoots was performed in batch mode, in a conical spouted bed combustor at temperatures ranging from 250 to 550°C, with and without the Pd catalyst. The influence of the catalyst and inlet gas temperature on the flue gas concentration was analyzed. The experimental vine shoot combustion yield with the Pd catalyst at different inlet gas temperatures were compared with those obtained without the catalyst. The high experimental combustion efficiency calculated from the flue gases concentrations demonstrates the favorable performance of the conical spouted bed combustor for the catalytic combustion of vine shoots.

Comparison between three types of ammonia synthesis reactor configurations in terms of cooling methods

In this study, simulation and optimization of ammonia synthesis reactor based on the implemented cooling methods was presented in three cases: internal direct cooling reactor (IDCR), adiabatic quench cooling reactor (AQCR), and adiabatic indirect cooling reactor (AICR). A one-dimensional pseudo-homogeneous model was developed to investigate the effect of various parameters on maximum N2 conversion at the outlet of IDCR, 2-bed AQCR and 2-bed AICR. Differential evolution algorithm was applied to optimize three types of ammonia synthesis reactor, considering N2 conversion as the main objective. A comparison between IDCR, 2/3/4-bed AQCR and 2/3/4-bed AICR was carried out under the optimal operating conditions by considering the same catalyst volume, operating pressure and feed mass flow rate for all three types of reactor. The optimization results show that a maximum conversion of 0.26 was achieved in 3-bed AQCR, in which the temperature of feed gas to the first bed was 635K, dimensionless lengths of each bed were 0.13, 0.25 and 0.62, and fractions of total feed flow rate quenching from the first to end bed were 0.2, 0.26 and 0.54, respectively. The optimum value of N2 conversion was found 0.3 in IDCR at the gas temperature to the cooling tube of 495K. In 3-bed AICR, the highest conversion of 0.3 was determined at temperature of inlet gas to each bed, 696K, and dimensionless length of each bed, 0.33. Generally, IDCR, 3-bed AICR and 3-bed AQCR were suggested as ammonia synthesis reactor configurations from the most favorable to the least favorable.