Full name: Nguyễn Trần Hoàn
Class: K4
Id code: CTTT13210126
ADECH 04
SELF STUDY 1: CHAPTER 2
Requirements
1) Interpretation of Shell- OMEGA technology for Ethyleneglycol (EG) manufacturing
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 ethylene carbonation using CO2.
4) Interpret production of Ethyleneglycol (EG) from synthesis gas via dimethyl oxalate
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.
Answer
1) Interpretation of Shell- OMEGA technology for Ethyleneglycol (EG) manufacturing
Ethylene glycol is produced from (ethene), via the intermediate . Ethylene oxide reacts with to produce ethylene glycol according to the :
C2H4O + H2O → HO–CH2CH2–OH
This can be by either or , or can occur at neutral under elevated temperatures. The highest yields of ethylene glycol occur at acidic or neutral pH with a large excess of water. Under these conditions, ethylene glycol yields of 90% can be achieved. The major byproducts are the oligomers diethylene glycol, triethylene glycol, and tetraethylene glycol. The separation of these oligomers and water is energy intensive. About 6.7 million tonnes are produced annually.
A higher selectivity is achieved by use of . In the OMEGA process, the ethylene oxide is first converted with (CO2) to . This ring is then hydrolyzed with a base catalyst in a second step to produce mono-ethylene glycol in 98% selectivity. The carbon dioxide is released in this step again and can be fed back into the process circuit. The carbon dioxide comes in part from the ethylene oxide production, where a part of the ethylene is completely .
Ethylene glycol is produced from carbon monoxide in countries with large coal reserves and less stringent environmental regulations. The oxidative carbonylation of methanol to dimethyl oxalate provides a promising approach to the production of C1-based ethylene glycol. Dimethyl oxalate can be converted into ethylene glycol in high yields (94.7%) by with a copper catalyst
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2) Draw block diagram of EG production from ethylene by hydration of ethylene oxide


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

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4) Interpret production of Ethyleneglycol (EG) from synthesis gas via dimethyl oxalate
The present invention relates to a process and a device system for producing dimethyl oxalate by high-pressure carbonylation of industrial synthesis gas and producing ethylene glycol by hydrogenation. The process comprises the steps of: using industrial NO, O2 and methanol as raw materials for an esterification reaction to produce methyl nitrite; and then using industrial CO and methyl nitrite for a carbonylation reaction in a plate reactor to produce carbonylation products, which mainly include dimethyl oxalate and dimethyl carbonate; separating the carbonylation products to obtain dimethyl carbonate products; subjecting dimethyl oxalate to subsequent hydrogenation in the plate reactor to produce ethylene glycol products; subjecting the waste acids in the esterification reaction and purge gases in the carbonylation reaction to a coupling recovery treatment for recycling. The system comprises an esterification reaction system, a carbonylation reaction system, a coupling recovery system for purge gases and waste acids and a hydrogenation reaction system. The process has the characteristic that device consumption is remarkably reduced, and particularly the nitric acid waste liquid recycling and purge gas recycling are highly coupled as well as the separation process thereof; recycling of the raw materials in reaction waste gases is realized, and the effect is remarkable.

5) Draw block diagram of EG from synthesis gas via dimethyl oxalate
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6) Comment on advantage and disadvantage of hydration, carbonylation and Shell OMEGA technologies.
• In hydration, the advantages are: continuous process, need few worker and fast at reaction rate, no by-product made; but the disadvantage are: uses non-renewable material (from crude oil), occurs at high temperature (300°C) and high pressure (60-70atm), uses a lot of energy…
• In carbonylation, we can save solvents; reduces the additional raw materials requied, the reactor occupancy time including the related costs for manpower, the time and the costs incurred in cleaning the reactors between different production steps, energy costs and costs in the analytical monitoring of reaction steps and intermediate products.
• In Shell OMEGA technology, OMEGA stands for “Only MEG Advantage” and was developed by Shell Global Solutions, Shell’s technology arm. Unlike conventional processes, OMEGA produces virtually no by-products (di-ethylene glycol and tri-ethylene glycol) which remove the need for handling and storage facilities.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 tone of MEG than conventional processes.