Abstract
The steam cracker unit at ORLEN Unipetrol is a significant European producer of monomers. Due to heavy feedstocks, the steam cracker can produce (besides ethylene, propylene and benzene) very valuable hydrocarbons such as dicyclopentadiene. The staff of ORLEN Unipetrol (formerly Chemopetrol) has been investigating the possibility of producing dicyclopentadiene for almost 40 years. As a result of many years of research activities of several generations of researchers, the technology for production of dicyclopentadiene of various quality grades has been developed and realized in the plant in Litvínov. The paper summarizes the history of research on the production of dicyclopentadiene from the moment of the construction of the steam cracker unit in Litvínov in 1980 to the moment when the unit was put into operation in 2022. The paper is primarily an appreciation to all the researchers who have been involved in the research and development of this product over the years and it can be an inspiration for the further development of C5 chemistry.