China completes first trial of methanol transport in fuel pipelines

China has completed its first field trial of transporting fuel methanol through long-distance refined oil pipelines, marking a key step from theoretical research to engineering application for the technology, according to PipeChina on Monday.

After a systematic evaluation of pipeline compatibility and safety upgrades at two stations, a total of 1,000 cubic meters of fuel methanol was transported in two batches through an existing refined oil pipeline from northwest China's Gansu Province to an oil storage facility in northwest China's Shaanxi Province. The entire process was conducted in a sealed and controllable environment.

The trial used a transportation method, in which methanol and gasoline were transported through the same pipeline. The total length of the mixed section between methanol and gasoline was kept below one kilometer, demonstrating the feasibility of large-scale methanol transportation, according to Wang Yubin, a senior engineer at PipeChina Research Institute.

At the receiving oil depot, the two materials were separated and transferred into different storage tanks, completing the full industrial verification process.

During the trial, researchers conducted two sets of tests under different operating conditions, including high and low flow rates, as well as pipeline start-up and shutdown scenarios. The tests verified the adaptability of sequential methanol transportation under complex terrain and different operating modes, providing a technical solution and engineering reference for large-scale, cross-regional methanol transport.

So how can an existing refined oil pipeline transport methanol while continuing to carry conventional fuels?

China already uses sequential transportation technology to move different grades of gasoline and diesel through the same pipeline. Different fuels are arranged like connected train cars, moving one after another. Once they arrive at the destination, the mixed sections are identified and separated before being stored in different tanks.

Methanol can be transported alongside gasoline because the two liquids mix easily. When transported sequentially, they form a shorter mixed section with gradual concentration changes, making separation easier.

However, methanol has poorer compatibility with diesel. Under low-flow conditions or in areas with uneven terrain, the two liquids can separate due to density differences, creating longer mixed sections and increasing separation difficulties.

Therefore, in this trial, methanol was transported between gasoline batches, allowing it to "ride" existing refined oil pipelines safely and efficiently to its destination.

The successful trial provides a new approach for expanding methanol transportation capacity and improving the utilization of existing energy infrastructure.