Topic: ammonia sythensis process

Group 3:
Nguyễn Tuấn Nghĩa
Cao Minh Thiệu
A.Prof:
Phạm Xuân Núi
content

I. INTRODUCTION

II. PROCESS
1, Materials
2, Mechanism of catalyst
3, Some advace process

III. TECHNOLOGY

IV. CONCLUSIONS
I. introduction

I.1 The importance of Ammonia :
- The chemical has many applications, especially in in agriculture (fertilizer..)

- prepared amoni salt

- prepared HNO3 acid, xoda..

-Prepared Hidrazin (N2H4) Fuel for misile

- liquid make cold in refrigerating machine




I. introduction
Whole simple process
II. PROCESS

II.1 Materials
* 2 Mains material is H2 and N2, from :
* 2 Main Source : Natural Gas and Coal

1.Natural gas: Natural gas (mainly methane CH4 contains) is transformed by steam or oxygen in the reaction:
CH4 + H2O  CO + 3H2
CH4 + 1/2 O2  CO + 2H2

CO formed is converted to hydrogen and CO2:

CO + H2O  CO2 + H2
II. PROCESS
II.1 Materials
2. Material is COAL
The allergic reaction can:
C + O2  CO2
2CO  C + CO 2
C + H2O  CO + H2
CH4  C + 2H2

The homogeneous reaction:
CO + 3H2  CH4 + H2O
CO2 + H2O  CO + H2
II. PROCESS
 1 Materials
End metabolism, we obtain the gas mixture N2 + H2 and CO2 and some impurities CO, CH4, H2S…

- Clean mixture gas : remove
CO2 and H2S by washing
with water at high pressure
II. PROCESS
2. Ammonia Synthesis Process
i.Equation
Haber–Bosch process : the main industrial route to ammonia from the reaction of dinitrogen and hydrogen gasses
II. PROCESS
2. Ammonia Synthesis Process
How the catalyst and promoter work?
Fe catalyst - The formation of Fe-O bonds  increases the free energy surface of Fe and increased absorption of Nitro, stretch the bonds of N---N , H-H

Al2O3 promoter- The presence of Al2O3 is offset oxygen to the iron surface, increased energy and surface area

K2O promoter- The presence of K2O is to reduce the surface area, but it provides electron. increased electron density and increase the active area on the surface
II. PROCESS
2. Ammonia Synthesis Process
Machenism :
II. PROCESS
2.  Ammonia Synthesis
ii. Mechanism
The reaction mechanism, involving the heterogeneous catalyst, is believed to involve the following 6 steps:
the mechanism of absorption-dissociation of nitrogen on the surface
II. PROCESS
2.  Ammonia Synthesis
ii. Mechanism

II. PROCESS
2.  Ammonia Synthesis
Something properties about catalyst and promote
- Fe is use as Industrial Catalysis
- The main components are magnetite catalyst
- Fe catalyst has high activity, high the energy destroy
the bonds
- Pore ​​structure


- Al2O3 Dispersed in the form of small molecules
FeAl2O4
II. PROCESS
3. Some Advance process
- conversion of molecular dinitrogen into ammonia or ammonia equivalent, silylamine, by using transition metal–dinitrogen complexes.
-Some example of transition metal–dinitrogen complexes.
II. PROCESS
A.Process 1 : Stoichiometric formation of ammonia by reaction with Brønsted acid
- the coordinated dinitrogen can be transformed into ammonia under mild reaction conditions by treatment with inorganic acids such as HCl, H2SO4..
Reaction: Conversion of molybdenum– and tungsten–dinitrogen complexes
to form ammonia
II. PROCESS
A.Process 1 - Mechanism
Chatt cycle: Protonation of molybdenum– and
tungsten–dinitrogen
- Chatt cycle include three
stages
* Part I: protonation of bound N2

* Part II: Cleavage of the N-N bond, generating the first molecule of NH3

* Part III: The reduction and protonation of nitrido complexes, leading to formation of the second equivalent of ammonia
II. PROCESS
B.Process 2:
- Stoichiometric formation of ammonia by reaction
with dihydrogen

Mechanisim: Reaction of a tungsten–dinitrogen complex with a ruthenium–dihydrogen complex to
form ammonia.
II. PROCESS
B.Process 2:
- NH3 synthesis from N2 and H3 very difficult in normal conditions
- It occurs in conditions of high temperature, high pressure

advantage of this process : with this mechanism it can happen even at room temperature
1atm and at 55*C

iii.technology
The most popular technology in ammonia synthesis process is haber technology.

To day, there are 5 most popular technologies apply the haber process in synthesis ammonia :

1/ Haldor Topsoe ammonia process technology

2/ M.W. Kellogg ammonia process technology

3/ Krupp Uhde ammonia process technology

4/ ICI ammonia process technology

5/ Brown & Root ammonia process technology
iii.technology
Some advantages of haber process

1/ The material is available with the large amount (natural gas and the air)

2/ This technology is cheaper

3/ This technology is applied widely and successfully in the world

4/ The overall conversion is about 98%
iii.technology
The Haber Process
iii.technology
This flow diagram illustrates the production of ammonia using the
Haber-Bosch process
iii.technology
The hydrogen for the ammonia synthesis was made by the water-gas process (a Carl Bosch invention) which involves blowing steam through a bed of red hot coke resulting in the separation of hydrogen from oxygen. The nitrogen was obtained by distillation of liquid air, then by cooling and compressing air.


These days, the hydrogen is produced by reforming light petroleum fractions or natural gas (methane, CH4) by adding steam:

CH4(g) + H2O(g)  CO(g) + 3H2(g) (T=700oC with Ni catalyst)

iii.technology
Enough steam is used to react with about 45% of the methane (CH4), the rest of the methane is reacted with air:

2CH4(g) + O2(g) + 4N2(g)  2CO(g) + 4H2(g) + 4N2(g) (Ni catalyst)

All the carbon monoxide (CO) in the mixture is oxidised to CO2 using steam and an iron oxide catalyst:

CO(g) + H2O(g)  H2(g) + CO2(g) (iron oxide catalyst)

The carbon dioxide (CO2) is removed using a suitable base so that only the nitrogen gas (N2) and hydrogen gas (H2) remain and are used in the production of ammonia (NH3).

In ammonia production the hydrogen and nitrogen are mixed together in a ratio of 3:1 by volume and compressed to around 200 times atmospheric pressure.


iii.technology
The reactor
iii.technology
Reaction in the reactor :






Some notes on the conditions:
Pressure is 200-500atm
Temperature is 500-600oC
The catalyst is very important

iii.technology
The mechanism
IV. conclusion
energy sources is getting reduction, ammonia is the source naturally material, it’ll tend to thrive in the future

Improve the catalysts which have higher selectivity, activity and longer life time

Technological improvements will help performance in the production process

Ammonia synthesis process will be the important process production of fuel in the future
THANK YOU FOR YOUR ATTENTION