胜华直馏柴油的固定床催化酯化脱酸

 针对柴油碱洗脱酸精制易乳化、收率低的问题，研究了催化酯化脱酸的技术来替代柴油碱洗脱酸。考察了在固定床催化剂存在下，影响柴油酯化脱酸的因素，并评价了酯化脱酸技术的经济性。结果表明，反应温度、空速、醇/油质量比、甲醇水含量等是影响柴油酯化脱酸的重要因素。反应温度高、空速降低、加大醇/油质量比有利于酯化反应的进行。甲醇中水的质量分数低于5%时，对酯化反应影响大，随水含量的增加，脱酸率显著降低；水的质量分数在5%~10%范围，脱酸率不再随水含量的增加而变化。对胜华直馏柴油来说，在反应温度280～300℃、反应空速1.5h^-1、醇/油质量比0.01条件下，脱酸效果明显。直馏柴油酯化脱酸比碱洗脱酸具有更好的经济效益。

ACID REMOVAL OF SHENGHUA DIESEL FUEL BY FIXED BED CATALYTIC ESTERIFICATION

Alkaline washing for the refining of straight diesel fuel distillation has the disadvantage of emulsion and low yield. A catalytic esterification method was studied to decrease the acid number of diesel fuel instead of alkaline washing. The influence factors were studied by using a fixed bed reactor at the presence of catalyst. The economic analysis of the catalytic esterification method was also carried out. Data indicated that the reaction temperature, space velocity, mass ratio of methanol to oil and mass fraction of water in methanol influenced the acid removal. High temperature, low space velocity, high mass ratio of methanol to oil, and low mass fraction of water in methanol fitted the esterification. When the mass fraction of water in methanol was lower than 5%, the acid removal rate decreased with the water content increase, while when the mass fraction of water in methanol was in the range of 5%-10%, the acid removal rate no longer changed with the water content increase. For Shenghua straight diesel distillate, the suitable reaction conditions included the reaction temperature of 280-300℃，space velocity of 1.5h-1，mass ratio of methanol to oil of 1%. The esterification to remove acid from diesel fuel has greater economic and social effects than Alkaline washing.