Khalighi Saman, Ferreira Abel G M, Santos Jaime B, Cruz Pedro F, Brito Rui M M
Department of Chemical Engineering, University of Coimbra, CERES, Polo II, Rua Silvio Lima, Coimbra 3030-970, Portugal.
Department of Electrical and Computers Engineering, University of Coimbra, CEMMPRE, Polo II, Rua Sílvio Lima, Coimbra 3030-970, Portugal.
ACS Omega. 2025 Jun 26;10(26):27699-27721. doi: 10.1021/acsomega.4c09412. eCollection 2025 Jul 8.
The study of oil and biodiesel viscosity for a wide range of temperatures and pressures is crucial for predicting the behavior in injection and combustion of fuel systems in diesel engines as well as for the optimization of these systems. In this work, the viscosity of waste cooking oil (WCO) and biodiesel (WCB) was measured within the global temperature range 298 to 373 K at atmospheric pressure. A rotational Brookfield viscometer was used for the viscosity measurements from which the rheological behavior of the oil and biodiesel was examined. The acquired data were then correlated using the Arrhenius, Vogel-Fulcher-Tammann, and Mauro equations. Among these, the latter two equations proved to offer the most accurate description of experimental data, yielding an average relative deviation (AARD) of 1.4%, compared to 4.6% and 3.6% obtained from Arrheniuśs equation for WCO and WCB, respectively. Additionally, various predictive methods including the Zong fragment-based approach, the group contribution method proposed by Ceriani, and recent methods derived from the Lewis-Squires equation were used to predict the experimental viscosity data, yielding reliable results. Specifically, for oils the Ceriani method resulted in an overall average relative deviation (OARD) of 8%, while for biodiesel the Lewis-Squires led to an OARD of 3%. This work describes in detail the sources of literature dedicated to the viscosity of used oils, with particular emphasis on used frying oils. A detail found in this study is that used oils from various sources, typically used in cooking, show a similar viscosity behavior with temperature, with only small variations between them. This is a fact rarely described in the literature.
研究各种温度和压力下油和生物柴油的粘度，对于预测柴油发动机燃料系统喷射和燃烧过程中的行为以及优化这些系统至关重要。在这项工作中，在大气压力下，于298至373K的全球温度范围内测量了废食用油（WCO）和生物柴油（WCB）的粘度。使用旋转布鲁克菲尔德粘度计进行粘度测量，据此研究了油和生物柴油的流变行为。然后使用阿伦尼乌斯方程、Vogel-Fulcher-Tammann方程和Mauro方程对获取的数据进行关联。其中，后两个方程对实验数据的描述最为准确，平均相对偏差（AARD）为1.4%，相比之下，WCO和WCB的阿伦尼乌斯方程分别得到的平均相对偏差为4.6%和3.6%。此外，还使用了各种预测方法，包括基于宗片段的方法、Ceriani提出的基团贡献法以及最近从Lewis-Squires方程推导出来的方法来预测实验粘度数据，结果可靠。具体而言，对于油类，Ceriani方法的总体平均相对偏差（OARD）为8%，而对于生物柴油，Lewis-Squires方法的OARD为3%。这项工作详细描述了专门研究废油粘度的文献来源，特别强调了用过的煎炸油。本研究发现的一个细节是，各种来源（通常用于烹饪）的废油在温度方面表现出相似的粘度行为，它们之间只有很小的差异。这是一个在文献中很少描述的事实。
