【Haichuan’s Best Practices】Installing a temporary line to address the serious safety risk posed by high-temperature alkaline solutions causing corrosion of equipment and pipelines

Thread Content

Recently, the alkylation unit in the Second Refining Production Department of Guangdong Petrochemical Company managed to eliminate the risk of high-temperature alkaline solutions corroding equipment and pipelines by installing a temporary line; this measure also allows for a savings of 55.9 kilowatt-hours of electricity per hour. 　　In the alkylation unit of Refining Production Department 2, the fresh alkali supply pump in the product purification system was selected with an oversized capacity; since the amount of alkali required for normal operation is relatively small, a situation arose where the larger-capacity pump was used to handle a smaller volume of alkali, resulting in most of the alkali solution being recycled back to the fresh alkali tank. Over time, the temperature of the medium in the fresh alkali tank rises increasingly, reaching up to 67°C. This high-temperature alkali poses a serious risk of corroding equipment and pipelines, thereby severely affecting the safe and stable operation of the facility. 　　To find a specific solution, the alkylation engineers conducted thorough research by consulting various sources, and actively sought advice from the patent holders of the process packages, design institutes, and experts in similar installations. They carried out repeated simulations of the process on-site and measured and calculated the positions of the pipelines; ultimately, it was determined that the most practical approach was to install a temporary line from the bottom of the fresh alkali tank to the alkali replenishment pump. The fresh alkali replenishment pump was changed from continuous operation to intermittent operation, in order to address the risk of corrosion to equipment and pipelines caused by the high temperature in the fresh alkali tank, as well as to reduce the energy consumption of the installation. 　　Upon receiving the task, the department’s equipment manager promptly coordinated with the maintenance team to get preparations underway on an urgent basis, while the renovation work proceeded in an orderly manner as well. To avoid carrying out welding work on site, equipment engineer Zhou Dongming organized the construction team to conduct precise measurements of the pipeline routes and slopes, carry out repeated tests and comparisons, verify the rationality of the process, and prepare everything in advance. After two days of installation and adjustment, the renovation was completed successfully. After the implementation of this minor technical upgrade, it further ensured the ‘stable, reliable, continuous, efficient’ operation of the plant.