Comparison of Different Synthesis Schemes for Production of Sodium Methoxide from Methanol and Sodium Hydroxide

Abstract

This research investigates the process simulation of sodium methoxide (NaOCH₃) synthesis from methanol (CH₃OH) and sodium hydroxide (NaOH) under three synthesis schemes: schemes A, B, and C. Scheme A consisted of one equilibrium reactor and two distillation columns, scheme B one reactive distillation column and one distillation column, and scheme C one reactive distillation column and pervaporation membrane. The simulation parameters included CH₃OH/NaOH feed flow ratio (1.2-1.6), number of stages (5-30), bottom flow rate (1400-1600 kg/h), and feed stage location (5, 10, 15, 20, 21, 22, 23, and 24). The simulation parameters were varied to determine the optimal NaOCH₃ synthetic conditions under different schemes with 0.01 wt% water content, maximum 45 wt% NaOCH₃, and the lowest total energy consumption. The results showed that scheme C had the lowest total energy consumption (34.25 GJ/h) under the optimal synthetic condition of 1.4 for CH₃OH/NaOH feed flow ratio, 25 for the number of stages, 1550 kg/h for the bottom flow rate, and the 24th feed stage location, with the NaOCH₃ flow rate of 675 kg/h. Scheme C thus holds promising potential as an energy-efficient alternative for synthesis of NaOCH₃. The novelty of this research lies in the use of pervaporation membrane in place of distillation column to separate CH₃OH from water and to lower energy consumption and capital cost.