Analytic Research on Adaptability of Key Equipment for Sequential Methanol Transportation in Product Oil Pipelines

Objective Some refined oil pipelines in China operate at low load rates. Utilizing these pipelines for batch transportation of methanol not only supports long-distance, large-scale methanol storage and transportation, but also maximizes pipeline asset utilization. The water solubility, strong polarity, volatility, flammability, toxicity, and other properties of methanol differ significantly from those of refined oil products such as gasoline and diesel, increasing the risk of corrosion in metallic components, swelling of non-metallic seals, and failure of existing risk prevention measures, thereby posing challenges to the adaptability of key equipment in refined oil pipelines. Methods In light of domestic and international standards, specifications, and engineering practices, the adaptability of key equipment—such as storage tanks, transfer pumps, valves, and flow meters—for methanol batch transportation via refined oil pipelines was thoroughly examined to establish an evaluation strategy from three perspectives: material adaptability, functional adaptability, and safety and environmental protection adaptability. Material adaptability focused on evaluating the service performance and lifespan of anti-corrosion coatings on storage tanks, metallic materials that are prone to corrosion (like carbon steel and cast iron) and in direct contact with the medium, and non-metallic sealing materials exposed to pressurized methanol. Functional adaptability focused on evaluating the floating roof of refined oil storage tanks, the transfer pump’s anti-cavitation performance, and the sealing performance of key equipment. Safety and environmental protection adaptability focused on evaluating the adaptability of the refined oil storage tank breathing system, exhaust gas recovery system, key equipment leakage monitoring system, and emergency response plan in a methanol environment. Results Based on the adaptability evaluation strategy, it is recommended that methanol storage tanks use stainless steel or carbon steel with fluoride or epoxy-modified coatings; sealing components employ polytetrafluoroethylene or other methanol swelling-resistant materials; and transfer pumps and valve bodies be made from 316L stainless steel or other highly corrosion-resistant materials. Storage tanks should feature steel explosion-proof internal floating roofs and multiple sealing systems to enhance airtightness. Transfer pumps require optimized inlet conditions and dynamic pressure/flow regulation algorithms to suppress cavitation and reduce oil mixing during pumping. Valves should incorporate zero-leakage sealing and fire/explosion protection for rapid emergency shutdown. For safety and environmental protection, key equipment safety systems should be improved across material selection, sealing control, leakage monitoring, volatile organic compound (VOC) recovery, and emergency response. Conclusion From the above results, establishing an adaptability evaluation and improvement strategy for key equipment can support methanol batch transportation via refined oil pipelines in China, advance the evolution of oil and gas pipeline systems toward multi-medium and new energy transportation, provide technical guidance for industry standards, and promote sustainable development in the energy sector.