用四丁基氢氧化铵和硬脂酸改进原油酸值 测定方法的研究

Modification of Oil Acid Number Measurements by Tetrabutyl Ammonium Hydroxide and Stearic Acid

蒋 平 吴 昊 葛际江 张贵才 丁 磊 裴海华

JIANG Ping，WU Hao，GE Jijiang，ZHANG Guicai，DING Lei，PEI Haihua

针对传统原油酸值滴定方法中电位突越不明显， 以及低酸值原油需要加入过多样品的问题， 采用四丁基氢 氧化铵 （TBAOH） 代替国标方法中的 KOH作为酸值的滴定用碱， 并在溶剂中添加了增强剂硬脂酸改进了原油酸 值的滴定方法， 通过对模拟油和不同地区原油酸值的测定， 比较了国标方法和改进方法的测量精确度。结果表 明， 与国标方法相比， 改进的原油酸值测量方法的精确度较高， 滴定结果相对误差较小， 滴定曲线拐点清晰， 一次 微分曲线的峰值明显； 对于酸值较低的原油， 即使在样品较少时改进的原油酸值测量方法仍有良好的重复性和 较高的实验精确度。图 16表 2参 13

Major changes including spiking crude oil samples and blank solutions with a known amount of stearic acid and replacing potassium hydroxide（KOH）with tetrabutyl ammonium hydroxide in titration were used to improve traditional measuring method of oil acid number，which had the defects that the oil with low acid number needed excess crude oil and did not have clear titration endpoint. The accuracy of modified titration method and national standard method was compared by testing the acid number of simulation oil and crude oil. The results showed that comparing national standard method，the modified titration method had higher accuracy，clearer titration endpoint，lower relative error and more evident peak value of first derivative differential curve，especially for the oil with low acid number and less sample amount.

10.19346/j.cnki.1000-4092.2018.01.029