Rui Marmota holds a Chemical Engineering degree from Instituto Superior Técnico and a post-graduation in Petroleum Refining and Petrochemistry from Universidade Nova de Lisboa. He also finished the curricular stage of an MBA in General Management from Universidade Católica Portuguesa.

Rui started his professional career in 1981 at Petroquímica e Gás de Portugal (PGP) as a process engineer, where he became responsible for some of its production units at the ammonia and town gas plants. In 1986, he was appointed production manager at the phthalic anhydride plant and thereafter he had the opportunity to cooperate with Davy-McKee Zimmer in the development of several international projects.

In 1994, Rui was invited to join Transgás, SPGN, as a member of the task force for the introduction of natural gas in Portugal, where he was responsible for the deployment of both the dispatching and the O&M teams of the high-pressure network. After the incorporation of Transgás in Galpenergia, in 1999, Rui continued to head those operational areas.

In September 2006, Rui joined REN as part of the process of legal unbundling of activities between supply and infrastructure operation, whereby REN purchased the high-pressure natural gas assets from Galpenergia. He was head of Gas System Management until 2016, after which he was appointed to his current position as head of Network Planning for both the electricity and gas networks.