Procedural Enhancements to Industrial Pipeline Flushing Operations

Every year in a single petroleum packaging facility, approximately 1,400 pipeline flushing operations occur between 1,000 petroleum products. Worldwide, this totals to hundreds of thousands of pipeline flushes annually. Pipeline flushing occurs during a product changeover, where the same pipeline must be used to process different types of petroleum products while maintaining the required product specifications. In typical flushing operations the existing product in the pipeline is addressed as the residual oil and the new product is known as the flushing oil. The new product (or flushing oil) is passed through the pipelines to remove any residual oil within the pipeline system. This results in mixing of the residual and flushing oils, thus generating large quantities of commingled oil. Due to the specifications for each of the pure petroleum lube oils, the commingled oil is non-usable for intended applications and must be sold as a downgraded product. This leads to economic losses and environmental concerns. Therefore, there is a need to optimize the pipeline flushing operations at an industrial scale to minimize the production of commingled oils. The goal of this work is to optimize this flushing process using creative solution strategies such as procedural enhancements at both pilot and industrial scales to minimize commingled oil production.

Procedural enhancements have been the focus of this research, involving little to no capital cost with no system reconfigurations required. We first analyzed the current pipeline flushing operations at an industrial partner facility to determine ways to improve current operations, such as the incorporation of air-blowing to better clear the lines of residual oil prior to flushing. The existing and suggested procedures were then tested on a newly developed benchtop pilot plant to determine whether the air-blowing technique was an improvement to the existing flushing procedure. After quantifying the improvement in flushing operations, this procedure was presented to the industrial partners, who accepted these changes. Our team then implemented this improved procedure on their industrial drum filling lines and trained their operators on this air-blowing technique. As a result of this improved procedure, there has been a significant reduction in flushing failures at their facility from approximately 10% to 1.4%. The cost-benefit analysis further revealed that on wider implementation of this new procedure, a single facility can save up to 40,000 to 70,000 gallons of lubricant per year, which is approximately 1.2 million dollars annually, and a reduction in waste by 30-50%.