Synthesis of Malic Acid on Montmorillonite K10: A Langmuir–Hinshelwood Kinetic Study

• Published in: Industrial & engineering chemistry research Vol. 58; no. 22; pp. 9257 - 9265
• Main Authors: Mattar Knesebeck, Annelorie, Ortiz, Ronald Wbeimar Pacheco, Wypych, Fernando, Zanoelo, Everton Fernando
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.06.2019
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.9b00583

To accelerate the reaction of hydration of fumaric acid (F) to produce malic acid (M), Montmorillonite K10 (MK10) was tested as a solid acid catalyst. The experiments were performed in a stirred pressurized batch reactor at a catalyst concentration of 4.7%–9.4% (w:w), and temperatures of 448–493 K for times up to 36000 s. The concentrations of F, M, and maleic acid (Mx) formed from a secondary isomerization reaction were determined at different reaction times by UPLC analysis. MK10 increased the final conversion of F to at least 20% without any observed decay of its catalytic activity for four cycles of use. A reliable catalytic model that assumes that the surface reactions of isomerization and hydration of F are the rate-controlling steps was suggested. External mass-transfer resistances and diffusional limitations were not important.