Rinaldi, 73, who headed the company that revived the 1,300-acre complex in 2012 when previous owner Sunoco exited refining, has expressed an interest in rescuing the plant that was his personal project until he retired in 2017. With extensive connections to the business and political leaders, to energy-industry executives, and to the refinery’s labor union, Rinaldi becomes the front-runner to assume ownership of the largest refinery on the East Coast.