Tampa Electric on Dec. 15 requested from the Florida Department of Environmental Protection air permit authorization to use self-unloading vessels at the unloading dock at coal-fired Big Bend Station on Tampa Bay.
A final permit for this had been issued in December 2014. On March 3, 2016, Tampa Electric requested an extension of the expiration date of the air construction permit. At the time, Tampa Electric proposed seeking authorization for self-unloading vessels operated by United Ocean Services Inc. (UOS), and additional time was requested to allow UOS to install the necessary equipment to facilitate self-unloading. The installation was delayed due to UOS “financial issues,” said the utility in the Dec. 15 application. Based on these circumstances, the department extended the project from Dec. 1, 2016, to June 1, 2018.
Said the Dec. 15 application: “The proposed project consisted of minor modifications to operate self-unloading ocean vessels at Big Bend Station. The project will utilize self-unloading vessels equipped with boom conveyor systems to unload solid fuels and/or supplemental materials directly into the existing Dravo hopper. Alternatively, the project will be capable of utilizing self-unloading vessels equipped with clam-shell crane unloaders to unload solid fuels and supplemental materials directly into receiving hoppers. The receiving and transfer hoppers contain angled chutes that discharge immediately above the existing conveyor. The angled chutes allow the material to slide down immediately onto the conveyor rather than simply dropping and creating fugitive dust emissions.
“The Dravo Unloader was taken out of service and demolished; however, the existing Dravo hopper was salvaged and modified to accommodate self-unloading vessels. The two existing transfer points (FH-004 and FH-005) were used to accommodate the use of self-unloading vessels equipped with boom conveyors and the Dravo hopper. Four additional transfer points (FH-05a, FH-05b, FH-05c, and FH-05d) will be used to accommodate the use of self-unloading vessels equipped with clam-shell crane unloaders and the new four receiving hoppers.
“Tampa Electric and UOS entered into a settlement agreement, dated July 15, 2016. This agreement names the Mississippi Enterprise as a self-unloading vessel and the Florida Enterprise as a non-self-unloading vessel. The Energy Enterprise is no longer available as a self-unloading vessel or non-self-unloading vessel. However, Tampa Electric requests authorization to use other contracted self-unloading vessels that are equipped with boom conveyors and/or clam-shell crane unloaders to unload solid fuels and supplemental materials to receiving hoppers at Big Bend’s dock.
“The final self-unloading project consists of minor modifications to use self-unloading vessels and demolition of the Dravo Unloader and modifications of the Dravo hopper to receive solid fuel and materials. The project used self-unloading vessels equipped with boom conveyor systems to unload solid fuels and supplemental materials directly into the existing Dravo hopper. Alternatively, the project also uses self-unloading vessels equipped with clam-shell crane unloader systems to unload solid fuels and supplemental materials directly into receiving hoppers.”
Both coal and petroleum coke are unloaded at the Big Bend site. Most of this material is burned in the Big Bend plant, while the rest is trucked inland to the Polk Unit 1 coal gasification power facility.