Acetalization of ethylene glycol with formaldehyde using cation-exchange resins as catalysts: batch versus reactive distillation

Acetals as Possible Diesel Additives

“…Thus, Sharma and Chopade (Chopade & Sharma, 1997a;Chopade & Sharma, 1997b) achieved a maximum of 50% (at 363 K) of conversion reacting formaldehyde with ethylene glycol and less than 50% (at 343 K) reacting ethanol and formaldehyde. Agirre et al (Agirre et al, 2010) studied the reaction between ethanol and butanal and the achieved maximum conversion was also around 50% (at 313 K).…”

“…(Agirre et al, 2010;Chopade & Sharma, 1997a) (see Figure 2). Acetalization reactions involving polyalcohols (like glycerol) are also carried out in two reversible steps: the first one where the alcohol reacts with the aldehyde molecule leading to the formation of the corresponding hemiacetal and the second one, where two hydroxyl groups of the hemiacetal join to form the corresponding acetal, releasing a water molecule (Chopade & Sharma, 1997b). Silva et al (da Silva Ferreira et al 2002) explained in detail the reaction mechanism for the reaction between glycerol and acetaldehyde, indicating all the different steps of the reorganization of the hemiacetal molecule.…”

“…Silva et al (da Silva Ferreira et al 2002) explained in detail the reaction mechanism for the reaction between glycerol and acetaldehyde, indicating all the different steps of the reorganization of the hemiacetal molecule. However, in Figure 3 a simplified scheme of the reaction mechanism proposed by Sharma & Chopade (Chopade & Sharma, 1997b) is shown. It must be mentioned that in the case of reaction between glycerol and acetaldehyde acetals formation was observed in the absence of catalyst although the reaction rate was extremely low.…”

“…In all cases thermodynamic limitations seems to be quite important There are really few publications explaining the kinetics of acetalization reactions in the literature. Only Sharma & Chopade and Agirre et al (Agirre et al 2010;Chopade & Sharma, 1997a;Chopade & Sharma, 1997b) have published kinetic information. Thus, they were able to develop a pseudo-homogeneous kinetic model that is able to describe the reaction behaviour according to the reaction mechanism explained in Section 2.1.…”

“… Reacting ethanol and acetaldehyde in the presence of an acid catalyst. The main reaction implies the production of 1,1 diethoxy ethane and water (Andrade et al, 1986;Capeletti et al, 2000;Chopade et al, 1997a;Chopade et al, 1997b;Kaufhold & ElChahawi, 1996;Mahajani et al, 1995). The last procedure is the most interesting one as it is quite a simple reaction and both reactants can have a renewable origin.…”