Process development for dimethylacetal synthesis: Thermodynamics and reaction kinetics

• Tipo: Artigo em Revista Científica Internacional
• Data: 2005

Autores

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

Revista

Título: Industrial & Engineering Chemistry Research

Páginas: 7287-7297

ISSN: 0888-5885

Editora: American Chemical Society

Indexação

ISI Proceedings

ISI Web of Knowledge - 17 Citações

ISI Web of Science

Scopus - 14 Citações

COMPENDEX

Classificação Científica

FOS: Ciências da engenharia e tecnologias

CORDIS: Ciências Tecnológicas > Engenharia > Engenharia química

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica