ADECH 04
SELF STUDY 1: CHAPTER 2

NGUYễN KHOA NGHị - K4
13210143

1) Interpretation of Shell- OMEGA technology for Ethyleneglycol (EG) manufacturing
Two versions of the Shell EO/EG process are licensed:
the Shell MASTER process, which is based on catalytic conversion of ethylene to EO and thermal conversion of EO to EG; and
the Shell OMEGA process, which is based on catalytic conversion of both ethylene to EO and EO to EG.
In the Shell MASTER process, EO and water are converted to glycols by thermal hydration in a tubular reactor. This process yields roughly 8–10% diethylene glycol (DEG) and triethylene glycol (TEG). The MEG yield depends on the amount of water used in the reaction. Excess water is removed by multiple-effect evaporation, and the individual glycol products are then recovered and purified by distillation.
In the Shell OMEGA process, EO is first reacted with carbon dioxide to form ethylene carbonate, which is then hydrolysed to MEG and carbon dioxide (Figure 1 overleaf). As EO is not present in the hydrolysis reaction, the co-production of DEG and heavier glycols is negligible. Both processes have the option to co-produce high-purity EO.

The related reactions are:
C2H4 +
1
2
O2 → EO (ethylene oxide) [and CO2 by product from EO reaction]
EO + CO2 → EC (ethylene carbonate)
EC + H2O → CO2 + MEG






2) Draw block diagram of EG production from ethylene by hydration of ethylene oxide


3) Draw block diagram of EG based on Shell OMEGA technology by ethylenecarbonation using CO2.














4) Interpret production of Ethyleneglycol (EG) from synthesis gas via dimethyl oxalate


In the whole process,methyl nitrite(MN), NO and methanol (ME) recycle and do not lose theoretically. The related reactions are presented as follows:

MN Regeneration:
2NO+0.5O2 +2CH3OH→ 2CH3ONO(MN)+ H2O

DMO Synthesis:
2CH3ONO+2CO→ CH3OCOCOOCH3(dimethyl oxalate - DMO)+2NO

MEG Production:
CH3OCOCOOCH3+4H2→CH2OHCH2OH(MEG)+2CH3OH

Total:2CO
1
2
O2+4H2 → CH2OHCH2OH(MEG)+H2O

5) Draw block diagram of EG from synthesis gas via dimethyl oxalate

/


6) Comment on advantage and disadvantage of hydration, carbonylation and Shell OMEGA technologies.
Carbonylation
Advantages:
- Use common materials → reduce the cost
- Able to control the process
- Most of the wastes can be recycled
Disadvantages:
- Oxygen is pumped during the process
- Complicate design
Hydration
Advantages:
- Simple
- Easy to build
Disadvantages:
- May contain other products
Shell OMEGA
Advantages:
Shell is the world’s leading licenser of ethylene oxide/glycol technology. Shell is also one of the world’s largest ethylene oxide (EO) producers and a significant global ethylene glycol (EG) manufacturer.
Shell’s OMEGA process for producing mono-ethylene glycol (MEG) from EO achieves a conversion efficiency of over 99% compared to around 90% for conventional processes. 
Unlike conventional processes, OMEGA produces virtually no by-products (diethylene glycol and triethylene glycol) which removes the need for handling and storage facilities.
OMEGA is the world’s first entirely catalytic process for production of EO/EG. OMEGA combines a CRI high selectivity catalyst for the conversion of ethylene to ethylene oxide (EO) with a catalytic process to convert EO to ethylene glycol.
OMEGA uses about 20% less steam and about 30% less wastewater than a traditional thermal conversion MEG plant with the same capacity. OMEGA produces significantly less carbon dioxide per tonne of MEG than conventional processes.
An OMEGA plant also costs less to build for the same MEG yield than a traditional plant, so it stands out on economic grounds as well.
Disadvantages:
- Require specific material
-Complicate design