Vapor–liquid and chemical equilibria model for formaldehyde–trioxane–sulfuric acid–water mixtures

Abstract

BACKGROUND: Trioxane (C 3 H 6 O 3 ) is industrially produced from aqueous formaldehyde (HCHO) solutions through catalytic distillation catalyzed by sulfuric acid (H 2 SO 4 ). Optimizing industrial process of the synthesis and developing new catalysts require a reliableCONCLUSIONS: The prediction results uncover that, in addition to its ability to accelerate the reaction, the catalyst H 2 SO 4 has strong abilities to increase the activity of 'real' reactant for trioxane synthesis and to promote the phase separation that is very important for drastically increasing the yield of trioxane, reducing the energy requirement for the trioxane synthesis, and decreasing the formation of the by-product formic acid. EXPERIMENTAL MaterialsThe reagents and components along with their supplier and purity are shown in Table 1. Aqueous solutions of formaldehyde wileyonlinelibrary.com/jctb

Conceptual design of a crystallization-based trioxane production process

“…The concentrated formaldehyde solution is fed to a reactor, where formaldehyde is partly converted to trioxane in the presence of an acid catalyst. Low conversion, caused by an unfavorable chemical equilibrium, and the formation of various low-boiling side products in small amounts, such as formic acid, methylal, or methyl formate, have stimulated research in catalyst optimization and reactor design [16,17,18,19,20,21,22,23]. The reactor product is fed to a separation train, which has to accomplish the following: (a) separate the rather small amounts of trioxane from the reactor product; (b) remove the water; and (c) recycle the rest.…”