甲酸钠热分解行为的实验研究

用差热—热重方法对甲酸钠的热分解过程进行了实验研究，采用滴定分析技术分析了甲酸钠在不同条件下热分解产物的组成。研究发现：在甲酸钠脱氢制草酸钠的工艺中，加热速率和反应温度是影响草酸钠收率的重要因素。纯甲酸钠在253℃熔融，在330℃左右缓慢分解为碳酸钠、氢气、一氧化碳和少量草酸钠；高于400℃发生激烈的放热反应，甲酸钠脱氢转化为草酸钠；高于440℃，草酸钠分解生成碳酸钠。因此，为了高收率的获得目的产物草酸钠，需要快速升温，生成草酸钠的最佳温度为400～420℃，过度加热将导致草酸钠深度分解。

Formation of sodium oxalate by thermal decomposition of sodium formate

The thermal decomposition of sodium formate, HCOONa, has been studied by thermogravimetric and differential thermal analyses. The products of thermal decomposition were analyzed by titrimetry. It was shown that after melting at 253℃, sodium formate slowly decomposes by hydrogen loss to Na₂CO₃, CO and Na₂C₂O₄ at 330℃. The rate of the decomposition reaction increases markedly at 400℃, associated with a large exothermic change. Sodium oxalate subsequently decomposes to sodium carbonate on heating above above 440℃. It was found that both the heating rate and maximum temperature have a significant effect on the yield of sodium oxalate. In order to maximize the yield of sodium oxalate, sodium formate should heated as rapidly as possible in order to shorten the reaction time, with the optimum temperature of thermal decomposition being from 400℃ to 420℃. Overheating may cause decomposition of the sodium oxalate. 