Unravelling the influence of water content, reaction time, and temperature on the heterogeneous synthesis of methyl formate

Abstract The atomic efficient synthesis of the fuel additive, methyl formate (MF), was performed with the ion exchange resin Amberlyst™ A26 OH, acting as a heterogeneous catalyst. CO gas feed for the carbonylation reaction of methanol contained 65 vol% of N2. A 33 central composite design was applied to investigate the influence of temperature, reaction time and water content, as well as their interactions on the MF yield. Moderate temperatures (30–55 °C), pressures (2.0–4.5 MPa), water content (0.01–0.1 vol%), and short reaction times (0.5–2 h) were chosen for enquiry. The global optimum, reaching 61.7 ± 3.5 %, was detected at 55 °C after 2 h with the lowest water content of 0.01 vol%. Under optimal reaction condition the reusability of A26 was confirmed and a five times higher MF yield was obtained in comparison to the homogenous catalyst NaOCH3. MF was selectively (≤99.9 %) formed in all experiments. The results confirm that the heterogeneous carbonylation simplifies and reduces energy expenditure of MF synthesis. Furthermore, the shown suitability as a downstream process of biomass gasification contributes to the zero-waste emission goal in transport and chemical sector.