Episode 3: Production of Synthesis Gas by Steam Methane Reforming
Episode 3: Production of Synthesis Gas by Steam Methane Reforming
Episode 3: Production of Synthesis Gas by Steam Methane Reforming
Unit
Value
Molar mass
g mol1
2.016
Heat of vaporization
J mol1
898
Density
kg m3
0.0899
Thermal conductivity
W m1 K1
0.1645
Molar heat
J mol1 K1
Cp = 22.0, Cv = 6.51
Property
Unit
Value
20.37
Density (liquid)
kg m3
70.00
Density (gas)
kg m3
1.319
Molar heat
J mol1 K1
Cp = 22.0, Cv = 6.51
Enthalpy
J mol1
7918
Thermal conductivity
W m1 K1
0.117
J mol1 K1
Cp = 23.49, Cv = 12.8
Enthalpy
J mol1
7020
Thermal conductivity
W m1 K1
0.0185
Critical Point
Temperature
33.00
Pressure
kPa
1339
Density
kg m3
30.09
Unit
Value
Molar mass
g mol1
28.010
Explosion range
(in air at 101.3 kPa)
% Volume
fraction
10.9 76
kg m3
1.250
Molar heat
J mol1 K1
Cp = 29.05,Cv =
20.68
Thermal
conductivity
W m1 K1
0.02324
Property
Unit
Boiling point (101.3 kPa)
Value
K
Melting point (101.3 kPa)
Temperature
K
Critical point
Temperature
K
Pressure
Kpa
Density
kg m3
81.65
Temperature
74.15
132.29
3496
301
Chemical properties of CO
Together with air, carbon monoxide forms explosive
mixtures in the concentration range of a CO-volume
fraction of (10.9-76%).In engineering, it is obtained by
separation from synthesis gas.
The reason for its toxicity is its property to displace
the oxygen from the hemoglobin-complex of blood,
since the affinity of hemoglobin (Hb) to CO is about
300 times higher than to O2. The hemoglobin of a
heavy smoker of cigarettes can reach a COsaturation of up to 15% in the course of a day.
Uses of syngas
1. Syngas can be used to produce a variety of chemicals like
ammonia and methanol.
2. Syngas itself can be used as a fuel in internal combustion
engine.
3. Syngas is also used as an intermediate in producing synthetic
petroleum for use as a fuel or lubricant via the Fischer
Tropsch process and previously the Mobil methanol to
gasoline process.
4. syngas can be used to produce organic molecules such as
synthetic natural gas (SNG-methane).
Product
Uses
H2 and N2
Ammonia
CO
Formic acid
H2 and CO
Acetic acid
Methanol
Methane
Unit
Molecular formula
Value
CH4
Molar Mass
g mol-1
16.04
Density at 25 C , 1
atm
g cm-3
0.656
Viscosity at -170 C
mPa.s
0.142
Specific heat
capacity at -100 C
J g-1 k-1
5.34
Melting point
-182
Flame Velocity
cm s-1
43.4
Critical Values
Temperature
- 82.5
Pressure
MPa
4.67
Density
g cm-3
0.162
Sources of Methane
Natural sources
1. Wetlands
2. Oceans
3. Geological sources
4. Wild animals
5. Wildfires
(H = +206 kJ/mol)
(H = -41 kJ/mol)
Catalyst
All tubular reformers use catalyst inside the
tubes in order to reduce the operating
temperature. This is important in order to
reduce the tube stresses resulting from high
pressure and high temperatures The Nicatalyst is needed since methane is a very
thermodynamically stable molecule even
at high temperatures. nickel catalyst filled
tubes to produce a synthesis gas.
Ni-catalyst is often in the form of thickwalled Raschig rings, with 16 mm in
diameter and height, and a 6 8 mm hole
in the middle.
Challenges
During the production of Synthesis gas, CO2
is also produced. The SMR process in
centralized plants emits more than twice the
CO2 than hydrogen produced. To avoid
emission of CO2 into the atmosphere, CO2
can be concentrated, captured, and
sequestered.
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