順酐在高溫下會發(fā)生分 解，隨之放出二氧化碳和大量熱量。對于高純度物質(zhì)順酐來說，事實上發(fā)生這種危險的可能性非常小。因為通常順酐的蒸餾溫度實際都低于其分解溫度。但如果在有以下各種催化物質(zhì)的存在下，發(fā)生順酐分解反應(yīng)的可能性會大大地增加。
Maleic anhydride will decompose at high temperature, and then release carbon dioxide and a lot of heat. For high purity maleic anhydride, in fact, the risk is very small. Generally, the distillation temperature of maleic anhydride is lower than its decomposition temperature. However, in the presence of the following catalytic substances, the possibility of maleic anhydride decomposition will be greatly increased.
順酐發(fā)生分解危險主要的催化物質(zhì)是堿金屬離子和胺類物質(zhì)，特別是鉀、鈉離子的危險性*大，即使鉀、鈉離子濃度很小時也會使馬來酐的分解溫度大大降低。只要有順酐的分解反應(yīng)發(fā)生，其分解反應(yīng)速度隨溫度的增加會迅速增加。如果讓分解反應(yīng)繼續(xù)進行下去，溫度和壓力會迅速聚集，促使分解反應(yīng)速度增加的更快，結(jié)果引起爆炸。
The main catalytic substances are alkali metal ions and amines, especially potassium and sodium ions. Even if the concentration of potassium and sodium ions is very small, the decomposition temperature of maleic anhydride will be greatly reduced. As long as the decomposition reaction of maleic anhydride occurs, the decomposition reaction rate will increase rapidly with the increase of temperature. If the decomposition reaction is allowed to continue, the temperature and pressure will gather rapidly, and the decomposition reaction speed will increase faster, resulting in explosion.
順酐開始發(fā)生分解反應(yīng)需要的溫度，是順酐中堿金屬污染物質(zhì)含量的函數(shù)。當(dāng)堿金屬離子的含量達到10ppm時，順酐開始發(fā)生分解反應(yīng)的溫度約為390-400℉(200-204℃)。
The temperature needed for the decomposition reaction of maleic anhydride is a function of the content of alkali metal pollutants in maleic anhydride. When the content of alkali metal ions reaches 10 ppm, the decomposition temperature of maleic anhydride is about 390-400 ℃ (200-204 ℃).
如果堿金屬如鉀、鈉離子含量增加時，順酐的分解反應(yīng)溫度會大幅度下降，甚可能降低到300℉(150℃)以下。隨著堿金屬物質(zhì)的存在，陰離子物質(zhì)也將起到促進順酐分解的作用，如磷酸鈉在初期的催化作用比碳酸鈉或馬來酸鈉鹽要低得多，但其促使順酐發(fā)生分解反應(yīng)以及爆炸的可能性是依然存在的，所以應(yīng)采取有效措施預(yù)防分解事故的發(fā)生。
If the content of alkali metals such as potassium and sodium ions increases, the decomposition reaction temperature of maleic anhydride will be greatly reduced, and may even be reduced to below 300 ℃ (150 ℃). With the existence of alkali metal substances, anionic substances will also play a role in promoting the decomposition of maleic anhydride. For example, the catalytic effect of sodium phosphate in the initial stage is much lower than that of sodium carbonate or sodium maleate. However, the possibility of decomposition reaction and explosion of maleic anhydride still exists. Therefore, effective measures should be taken to prevent the occurrence of decomposition accidents.
