For over 30 years, our Refinery Services business, operating as TDC, has been a leading producer of sodium hydrosulfide (NaHS). ...

Our Refinery Services business, operating as TDC, is a leading supplier of caustic soda (NaOH). ...

Sulfur Services, doing business as TDC, provides engineering, logistics, and technical services to our refinery and petrochemical customers. ...