Process development for dimethylacetal synthesis: Thermodynamics and reaction kinetics

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Ganesh K. Gand (Author) FEUP; Viviana M. T. M. Silva (Author) FEUP; Alírio E. Rodrigues (Author) FEUP

Journal

Title: Industrial & Engineering Chemistry Research

Pages: 7287-7297

ISSN: 0888-5885

Publisher: American Chemical Society

Indexing

ISI Proceedings

ISI Web of Knowledge - 17 Citations

ISI Web of Science

Scopus - 14 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology

CORDIS: Technological sciences > Engineering > Chemical engineering

Other information

Authenticus ID: P-000-1CG

DOI: 10.1021/ie048775u

Abstract (EN): The synthesis of acetaldehyde dimethylacetal was studied in a batch reactor by the acetaldehyde and methanol reaction in the liquid phase, using the acid resin Amberlyst-15 as the catalyst. Acetal synthesis was also performed with Y-type zeolite in order to compare the results for both catalysts. The reaction equilibrium constant was determined experimentally in the temperature range 293.15-333.15 K at 1.0 MPa: K-eq = 0.0143 exp[2142.5/T(K)]. The standard molar reaction properties were obtained at 298.15 K: Delta S degrees = -35.34 J mol(-1) K-1, Delta H degrees = -17.81 kJ mol(-1), and Delta G degrees = -7.28 M mol(-1). Kinetic experiments were carried out in the temperature range 293.15-313.15 K at 0.6 MPa. A two-parameter model based on a Langmnir-Hinshelwood rate expression was considered, using activity coefficients from the UNIFAC method, which can describe the experimental kinetic results. The kinetic law is R = k(C)[a(A)a(B) - a(C)a(D)/(K(eq)a(A))]/(1 + K(sD)a(D))(2), and the parameters are k(C) = 6.91 x 10(13) exp[-8 702.6/T(K)] mol g(-1) min(-1) and K-D = 2.37 x 10(32) exp[-22 713/T(K)]. The activation energy of reaction for the synthesis of acetal is 72.35 kJ mol(-1). The relationship between the effectiveness factor and the Thiele modulus was determined.

Language: English

Type (Professor's evaluation): Scientific