The 1,300-acre property, which is larger than all of Center City, could be sold to one buyer, or broken up into pieces and sold to several buyers. The site has been used for petroleum refining for more than 150 years. But the refinery’s shutdown, and its continued struggles with financial viability as a conventional oil processing plant, have also raised hopes among urban planners, environmentalists, and the refinery’s neighbors that a new, cleaner use can be found for a large property at the city’s southern gateway.