Modeling & Simulation of Methanol Synthesis from Syngas
Modeling & Simulation of Methanol Synthesis from Syngas
Under Guidance of Presented By Dr. Shashi Kumar Shashank Tandon
Associate Professor CAPPD, 2nd Year1
OUTLINEObjectives
Reaction rate and Kinetics
Development of Modeling Equations
Useful Definitions
Validation of Model
Modeling Results
Effect of the parametersTemperaturePressureH2 : CO2 ratio
Conclusion
References
22OBJECTIVESFormulating a one dimensional mathematical model for
methanol production from syngas in a shell and tube fixed bed
reactor.
Solving the mathematical model using equation solver tool in
MATLAB with Runge-Kutta-Verner fourth and fifth order method.
Validating the model by comparing the predicted results with
those available in the literature.
Perform the simulation of shell and tube fixed bed reactor for
methanol synthesis from syngas and to study the effects of
following parameters on molar flow rates of hydrogen, carbon
dioxide, methanol, yield of methanol, conversion of hydrogen and
conversion of carbon dioxideTemperaturePressureH2:CO2 molar feed
ratioObtaining the optimal parametric condition for the maximum
production of methanol.3REACTION RATE AND KINETICS
Reactions involved are Hydrogenation of carbon monoxide CO +2H2
CH3OH H298= - 90.55 kJ.mol-1
Hydrogenation of carbon dioxide CO2 + 3H2 CH3OH + H2O H298= -
49.43 kJ.mol-1 Reverse Water-gas shift reaction CO + H2O CO2 + H2
H298= 41.12 kJ.mol-1
Catalyst Used : Cu/ZnO based with oxide additives Al2O3, Cr2O3
and ZrO2
4REACTION RATE AND KINETICS
Model utilizes the kinetic equation proposed by Vanden Bussche
and Froment in 1996.
CatalystTemperature
[K]Pressure
[bar]Cu/ZnO 453-55315-515All the constants (kj) in the above
equation follow the general Arrhenius equation. Russian groups led
by Rozovskii and Temkin found that neither of these groups
succeeded in producing methanol from a dry mixture of CO and H2. So
the models are all based on direct hydrogenation of CO2 to methanol
along with the occurrence of RWGS5Catalyst Properties, Feed
Conditions and Reactor Specification
ParameterValueUnitFeed composition (mole
%)H280-CO4.76-CO22.95-CH3OH0.3-H2O0.06-N20.01-CH411.92-Inlet
temperature498KInlet pressure50BarNumber of tubes5947-Flow rate of
feed gas47400Kmol hr -1Length of tube10mTypical properties of
catalystDensity of catalyst bed1063kg m-36All the constants (kj) in
the above equation follow the general Arrhenius equation. Russian
groups led by Rozovskii and Temkin found that neither of these
groups succeeded in producing methanol from a dry mixture of CO and
H2. So the models are all based on direct hydrogenation of CO2 to
methanol along with the occurrence of RWGS6DEVELOPMENT OF MODELING
EQUATIONSASSUMPTIONSA plug flow reactor model is assumed.The gas
mixture is considered as an ideal gas.Since the ratio of bed length
of catalyst (10m) to the particle size of catalyst (0.04m) > 50,
the radial diffusion in the catalyst particles is neglected in the
shell and tube fixed bed reactor.The reactor is simulated in the
steady state condition and one dimensional mathematical model is
considered.7DEVELOPMENT OF MODELING EQUATIONS88DEVELOPMENT OF
MODELING EQUATIONS9USEFUL DEFINITIONS1010RESULTS &
DISCUSSIONSValidation of model
Panahi et. al.Matlab ModelPercentage ErrorCO2
Conversion49.1547.8552.634Temperature528.2515.252.45211MODELING
RESULTS
12EFFECT OF PRESSURE ON METHANOL FLOWRATE13
EFFECT OF PRESSURE ON METHANOL FLOWRATE14
Same Trend is observed for other Temperatures also.14EFFECT OF
PRESSURE ON CO2 CONVERSION15
15EFFECT OF PRESSURE ON CO2 CONVERSION16
Same Trend is observed for other Temperatures also.16EFFECT OF
PRESSURE ON CO CONVERSION17
17EFFECT OF PRESSURE ON H2 CONVERSION18
18EFFECT OF PRESSURE ON CH3OH YIELD w.r.t. C 19
19EFFECT OF PRESSURE ON CH3OH YIELD w.r.t. H2 20
20EFFECT OF TEMPERATURE ON METHANOL FLOWRATE21 T P478 K488 K498
K508 K518 K38 bar1070.5841071.7181072.7851073.871073.8750
bar1253.2081254.4051255.5921256.7741257.942
EFFECT OF TEMPERATURE ON CH3OH YIELD w.r.t. C 22 T P478 K488
K498 K508 K518 K38 bar29.2946329.3256529.3548529.3845629.4142450
bar34.2918234.3245734.3570434.389434.42136
22EFFECT OF TEMPERATURE ON CO2 CONVERSION23 T P478 K488 K498
K508 K518 K38 bar41.9203741.8926341.866441.8419841.8137250
bar47.9065247.880747.8552547.829847.80433
23STUDY ON EFFECT OF TEMPERATURE24
24STUDY ON EFFECT OF TEMPERATURE`25
25EFFECT OF H2 : CO2 MOLE RATIO ON METHANOL FLOWRATE26
27EFFECT OF H2 : CO2 MOLE RATIO ON CH3OH YIELD w.r.t. C
27CONCLUSION28The optimal parametric conditions for the maximum
production of methanol are
HIGH PRESSURE (P=50 bar)LOW TEMPERATURE ( T=473 K)H2/CO2 MOLE
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