Yisung began his career as a fine chemical trader in 2011 and has been involved in biofuel business development and trading since 2019. He has pioneered UCO trading and studied the feasibility of HVO in Hyosung. 

In 2021, he moved to DS DANSUK (a Representative UCOME producer and exporter in Korea).  At DS , he has led and managed the HVO/SAF project through the Joint Venture with LG Chemical as Project Manager, in charge of planning feedstock procurement and the marketing of Sustainable Aviation Fuel.

He also led the sustainable marine fuel development in 2024 in KPIC, and now he is leading the biofuel business at STX Corporation as project manager.