Optimizing Pipeline Flushing Processes for Efficient Lube Oil Blending and Packaging Operations

Lube oil consists of a base oil blended with additives to enhance the desired properties of the base oil. These oil products have unique combinations of additives which distinguish them from other blends. Lubricant oil blending plants are required to meet diverse needs of customers, which can include engine oils, turbine oils, chain oils, and more. Customers also have increasing quality standards to ensure product integrity since contamination of different additives can affect the performance of an oil. Lube oil blending plants must be well equipped to process thousands of unique compositions of lube oil products. In the lube oil process industry, one single pipeline network is used for packaging thousands of different products. A cleaning method implemented in the lubricant industries is referred to as “flushing”. Traditionally for cleaning operations, a polyurethane instrument which is called a pipeline ‘pig’ is sent through the straight runs of the pipeline network. The pig scrapes the inner walls of the pipeline to remove any leftover product. However, there are certain sections of the pipeline network through which the rigid pig cannot be passed. These sections have to be flushed by a finished product for a set period of time. As a result, the finished product gets downgraded and is sold as a low-grade product which reduces its economic value. This makes the flushing operation highly cost-intensive and adds to a significant environmental burden associated with the disposal of the generated waste. Thus, the main goal of this study is to minimize the amount of downgraded oil that is generated during flushing. This can be achieved by implementing potential alternatives to the traditional flushing techniques. Potential solutions were investigated through literature review, planned experiments, and computational modeling. The experiments conducted provided insights into the oil-surface interaction to carbon steel piping as well as how different pipeline coatings would change that interaction. Computational tools such as CFD were used for analyzing the complex flow regimes in the pipelines. These models can demonstrate the effect of operating conditions on the fluids, which in turn can be modified to optimize the flushing process. This work will provide insights into several methods that have the potential to reduce the amount of downgraded oil in flushing operations.