May-2019

Ball valves for methanol-to-olefins project (TIA)

A methanol-to-olefins (MTO) project in China, scheduled for start-up in 2019, is installing rising-stem ball valves from Union Tech.

Robert Hsia
Union Tech

Article Summary

The company was awarded a contract consisting of Z4 rising-stem ball valves and paired actuators to be installed in Nanjing Chengzhi Yongqing Energy Technology’s 600 kt/y methanol-to-olefins (MTO) project by Wison Energy Engineering, the EPC for the project. The project, which converts methanol from coal and other sources into olefins that are the essential ingredients for plastics production, licenses Honeywell UOP’s MTO technology.

MTO is a recently developed process technology that converts methanol to olefins (ethylene, propylene, and/or butylene). The ability to convert methanol from different raw materials into olefins diversifies the requisite feedstocks to yield olefins. This technology enables regions rich in coal but potentially lacking in oil feedstocks to economically produce olefins. The project will be the second MTO plant at the site.

Union Tech’s Z4 rising-stem ball valves will be used throughout the processing units with the mixed olefins produced by the MTO reactors as the media. The process itself presents several challenges to traditional valves:
• Substantial variations in temperature and pressure
• Media contains particulates which present corrosion and erosion risks
• Frequent cycling operation.

The Z4 rising-stem ball valve was ultimately selected for the process as it was specifically engineered for these types of applications. The valves employ a tilt-and-turn design, enabling frequent cycling, zero leakage, and low torque operation; these types of valves are often used in high performance applications requiring frequent cycling with positive shut-off operation, such as in gas processing plants using molecular sieve systems for switching service, pipelines, and gas transmission.

The contract spanned a wide range of valve sizes, from 1.5in up to 10in. Union Tech manufactured both the valves and matching linear pneumatic actuators. Final inspections were conducted and passed in August 2018 at Union Tech’s Houston, Texas facilities, and the valves were subsequently shipped to the Chengzhi Yongqing MTO plant (see Figure 1). Union Tech manufactured and shipped the valves and actuators within 24 weeks, which can be an aggressive timeframe for rising stem ball valves.

This short case study originally appeared in PTQ's Technology In Action feature - Q2 2019 issue.

For more information: robert.hsia@uniontechmfg.com