Ethylene glycol synthesis

RD may also be a favorable alternative if complex reactions comprising consecutive and parallel reaction steps are considered. A prototypical reaction system for further study is the synthesis of ethylene glycol (EG) from ethylene oxide (EO) and water (W) according to 

The first reaction leads to the desired product whereas di-ethylene (DEG) and higher order glycols are formed in consecutive reactions as undesired by-products. The reaction rate constants of the consecutive reactions are higher than that of the main reaction. Hence, an appropriate process has to be devised in order to achieve satisfactory conversion and selectivity. 

As in the case of the esterification process presented before, we study first a one-stage column by singularity analysis to gain some physical insight and then continue with a numerical bifurcation study of an industrial size RD column. 

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Stein E, Kienle A, Esparta ARJ, Mohl KD, Gilles ED. Optimization of a reactor network for ethylene glycol synthesis—an algorithmic approach. Comp Chem Eng 1999 23 903-906. 

Fahey discusses free formaldehyde as an intermediate in the ethylene glycol synthesis [68]. 

Reductive dimerization of formaldehyde has. however, also been proposed to explain ethylene glycol synthesis [12]. The formation of formyl species might be considered as a key step, at least under special conditions, despite the unfavourable thermodynamics. The reaction is an endothermic process at room temperature [45] and the direct insertion of CO into a metal-hydrogen bond has never been observed. 

Fu J, Krauland E, Har-el Y, Hanes J. Biodegradable cationic poly(aspartic anhydride-co-ethylene glycol) Synthesis, characterization, and self-assembly with plasmid DNA, submitted to Macromolecules. 

Ethylene glycol synthesis by hydration of ethylene oxide (Fig. 7.6)... 

A model of a one-stage distillation process for ethylene glycol synthesis is reported by Gehrke and Marquardt [23]. Singularity analysis reveals a codimension 4 singularity for a Damkohler number Da = 0.0247, a heat duty Q/(AHvF) = 0.2871 and feed concentrations = 0.4597, = 0.072, = 0.3961, Xj q = 0.072. How-... 

Fig. 10.8 Bifurcation diagrams for ethylene glycol synthesis one-stage column (bottom) and ten-stage distillation column (top)...

Fig. 10.11 Influence of mixing on the multiplicity behavior of an RD column for ethylene glycol synthesis. Perfect mixing (top row), imperfect mixing (bottom row). The diagrams on the right sho A/ the detail in the vicinity of the upper left turning point of the diagrams on the left...

FIGURE 3.11 Poly(ethylene glycol) synthesis having active functional end groups (Nu", nucleophile or OH E", electrophile or proton). 

Ethylene glycol synthesis directly from CO/H2 using Ru-Rh catalysis or Ru alone (5,6). 

T., Hult, A., and Malkoch, M. (2013) Multifunctional Poly(ethylene glycol) synthesis, characterization, and potential applications of dendritic-linear-dendritic block copolymer hybrids. Macromolecules, 46 (10), 3726-3736. 

Fixed-point algorithm is not recommended by Ciric and Gu (1994) and Espinosa et al. (1996) for systems where the reaction kinetics, heat of reaction, liquid hold-up and residence times are the determining design variables. However, Okasinski and Doherty (1998) successfully use it to reproduce the ethylene glycol synthesis example of Ciric and Gu (1994). 

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