Siemens to supply rotating equipment for propane dehydrogenation plant in China

China’s largest acrylic producer, Zhejiang Satellite Energy Co., Ltd, recently selected Siemens to provide a reactor effluent compressor train for Phase II of its propane dehydrogenation (PDH) plant in Pinghu City in China’s Zhejian province. The dual-casing compressor train, scheduled for installation in late 2018, consists of two Siemens STC-SH single-shaft compressors driven by a Siemens SGT-750 industrial gas turbine. Plant commissioning is scheduled for early 2019.

This order follows the Satellite Phase I PDH project, where Siemens supplied a compressor train consisting of two STC-SH (14) compressors and a SGT-700 gas turbine in 2013. The Phase II project represents the first downstream application for Siemens SGT-750 gas turbine. The turbine’s advanced fuel flexibility and low lifecycle cost due to high reliability and ease of maintenance were critical factors in Zhejiang Satellite’s decision, along with their past success with Siemens’ technology.

The SGT-750 is optimized for direct drives without intermediate gears and has a rotational speed of 6,100 revolutions per minute. Further to this, the SGT-750 gas turbine enables long intervals between maintenance events, which increases production uptime and reduces lifecycle cost.

Siemens STC-SH single-shaft compressor offers a robust, dependable design with standardized components for ease of maintenance. The compressor is particularly well suited for petrochemical process applications with a wide range of volume flows.

Compared with steam turbine-driven or electric motor-driven compressor solutions more commonly used in PDH processes, gas turbine-driven solutions are able to use waste gas generated in the process. This allows for significant fuel cost savings resulting in lower lifecycle costs. Siemens is the only manufacturer with proven experience burning waste gas with dry low emission (DLE) technology.

“The high fuel flexibility and low emissions of our SGT-750 machines were also crucial considerations for this project,” explains Girish Garg, vice president, New Equipment for the Dresser-Rand business’ Middle East, China and Asia Pacific region. “Despite the high concentration of ethane in the gas used for firing, the SGT-750 achieves low nitrogen oxide emissions of only 25 parts per million.”