Gerard B. Hawkins Managing Director, CEO

• Reactions • Equilibrium • Catalyst Activity • Byproducts

Key synthesis reaction is

CO2 + 3H2 <=> CH3OH +H2O

Heat of reaction is -49 kJ/kmol Equilibrium reaction Also Water Gas Shift Reaction

WGS reaction is

CO + H2O <=> CO2 + H2

Heat of reaction is -41 kJ/kmol Equilibrium reaction This combines with the methanol synthesis

reaction to convert CO to methanol

CO +2H2 <=> CH3OH

The reaction rate is defined by the following equation

−=

13

22

322

3 1KHPCOP

OHCHPHPCOPkpdt

OHCHd mn

.][].[][.][.][.][

Where P[] is the partial pressure

Kinetic Term Equilibrium Term

Due to water gas shift reaction can also have this equation in terms of CO

Powers for this equation are ◦ n is 0.5 ◦ m is 1.5 ◦ This is from one source ◦ Other sources have different powers

Our belief is methanol is produced from CO2

The reaction rate is defined by the following equation

−=

12

2

32

3

.][].[][1.][.][.][

KHPCOPOHCHPHPCOPkp

dtOHCHd mn

Where P[] is the partial pressure

Kinetic Term Equilibrium Term

Catalysis in action

High science at the atomic level

150 200 250 300 350 400 4500.000001

0.00001

0.0001

0.001

0.01

0.1

1

Temperature (°C)

Kp

- Equ

ilibr

ium

Con

stan

t 1 bara

100 bara

200 bara

As can be seen pressure has a large effect Note Y axis is a log scale

ML % mol

Catalyst Volume

Increasing Pressure

Increasing Temperature

ML % mol

Catalyst Volume

Equilibrium Lines

180 200 220 240 260 280 300 3200

2

4

6

8

10

12

14

Temperature (°C)

Rel

ativ

e R

ate

Kinetically Limited Equilibrium Limited

Maximum Rate

Maximum rate line is where the maximum methanol reaction rate occurs.

By following this line, the minimum catalyst volume will be achieved for a given duty

Therefore should try and ensure reaction path follows this line closely

Each type of converter tracks this line in a particular way

Met

hano

l Con

cent

ratio

n (m

ol-%

)

Equilibrium line

Temperature (°C)

Max Rate Line

Met

hano

l Con

cent

ratio

n (m

ol-%

)

Equilibrium line

Temperature (°C)

Want to be here !

180 200 220 240 260 280 300 320 0

2

4

6

8

10

Temperature (°C)

Met

hano

l Con

cent

ratio

n (m

ol%

) Max Rate Curve

Methanol Equilibrium

180 200 220 240 260 280 300 320 0

2

4

6

8

10

Temperature (°C)

Met

hano

l Con

cent

ratio

n (m

ol%

)

Max Rate Curve

Methanol Equilibrium

Also some side reactions The following species are produced ◦ Alcohol's - Ethanol, propanol, butanol & pentanol ◦ Ketones - Acetone, Methyl Ethyl Ketone etc. ◦ Formates - Methyl Formate ◦ Ethers - Di Methyl Ether (DME) ◦ Acetates - Methyl Acetates ◦ Hydrocarbons Methane C2-C9's Parrafinic Waxes C10 +

By product reactions are as follows ◦ Ethanol :

2 CH3OH + H2 <===> CH3-CH2OH + H2O ◦ Acetone :

CH3-CHOHCH3 <===> CH3-CO- CH3 + H2 ◦ DME :

2 CH3OH <===> CH3-O-CH3 + H2O ◦ Methane :

CO + 3H2 <===> CH4 + H2O

Exothermicity ◦ Methanol is thermodynamically less stable than other

possible by-products ◦ Highlighted by heats of reaction

Free Energy of Formation ◦ Methanol is thermodynamically less likely to be formed

than other possible products ◦ Highlighted by free energy of formation

Crude production rates Converter space velocity Converter temperatures Gas compositions, CO and H2 mainly Catalyst impurities Oil leaks

Ethanol favored by ◦ high temperatures and CO partial pressures ◦ high levels of sodium ions ◦ high levels of active iron

Higher alcohols are ◦ Limited by kinetic formation rate ◦ A function of CO/H2 ratio

Exit Bed Temp °C 280 300 315

Ethanol 0.21% 0.447% 0.62%

Ketones dependent on temperature ◦ Acetone is a key light which must be removed in

the Topping column ◦ MEK is virtually impossible to remove by distillation

and will end up in the product Methyl Formate is equilibrium limited ◦ Little variation with temperature ◦ Easier to top than acetone.

DME is equilibrium limited ◦ Very volatile and easy to remove in the topping

column Methane favored by high temperatures and high

levels of active iron

Ammonia produced in the reformer will react in the loop with methanol to form TMA ◦ As occurs in LTS on Ammonia plants ◦ Will not be removed in distillation ◦ Causes product to smell ‘fishy’

Wax Formation ◦ Waxes are formed in synthesis converter ◦ Gaseous at converter temperatures ◦ Form solids on cooling - typically in crude coolers ◦ This leads to fouling of the crude coolers

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