Department of Chemical and Process Engineering, Chemical Faculty, Gdańsk University of Technology, 11/12 Narutowicza St, 80-233 Gdańsk, Poland.
Anal Bioanal Chem. 2011 Mar;399(9):3253-60. doi: 10.1007/s00216-010-4427-8. Epub 2010 Dec 12.
The distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures is often investigated by simulated distillation (SIMDIS) using capillary gas chromatography (CGC) with a short capillary column with polydimethylsiloxane as the stationary phase. This paper presents the results of investigations on the possibility of replacing currently used CGC columns for SIMDIS with a deactivated fused silica capillary tube without any stationary phase. The SIMDIS technique making use of such an empty fused silica column allows a considerable lowering of elution temperature of the analytes, which results in a decrease of the final oven temperature while ensuring a complete separation of the mixture. This eliminates the possibility of decomposition of less thermally stable mixture components and bleeding of the stationary phase which would result in an increase of the detector signal. It also improves the stability of the baseline, which is especially important in the determination of the end point of elution, which is the basis for finding the final temperature of distillation. This is the key parameter for the safety process of hydrocracking, where an excessively high final temperature of distillation of a batch can result in serious damage to an expensive catalyst bed. This paper compares the distribution of distillation temperatures of the fraction from vacuum distillation of petroleum obtained using SIMDIS with that obtained by the proposed procedure. A good agreement between the two procedures was observed. In addition, typical values of elution temperatures of n-paraffin standards obtained by the two procedures were compared. Finally, the agreement between boiling points of polar compounds determined from their retention times and actual boiling points was investigated.
液体和半流体产品（包括石油馏分和产品）的蒸馏温度分布是一个重要的过程和实际参数。它提供了有关原油性质和特定馏分含量的信息，这些馏分根据其沸点进行分类，以及常压或减压蒸馏的最佳条件。目前，通常通过模拟蒸馏（SIMDIS）使用带有聚二甲基硅氧烷作为固定相的短毛细管柱的毛细管气相色谱（CGC）来研究蒸馏温度的分布。本文介绍了用没有任何固定相的钝化熔融石英毛细管管代替目前用于 SIMDIS 的 CGC 柱的可能性的研究结果。利用这种空熔融石英柱的 SIMDIS 技术可以大大降低分析物的洗脱温度，从而降低最终炉温，同时确保混合物的完全分离。这消除了较热不稳定性混合物成分分解和固定相流失的可能性，否则会导致检测器信号增加。它还提高了基线的稳定性，这在确定洗脱终点时尤为重要，这是找到蒸馏最终温度的基础。这是加氢裂化安全过程的关键参数，其中一批的蒸馏最终温度过高可能会对昂贵的催化剂床造成严重损坏。本文比较了使用 SIMDIS 和建议的程序获得的石油减压蒸馏馏分的蒸馏温度分布。观察到两种程序之间的良好一致性。此外，还比较了两种程序获得的正构烷烃标准品的洗脱温度的典型值。最后，研究了从保留时间和实际沸点确定的极性化合物沸点之间的一致性。
