The Kentucky Department for Environmental Protection on Dec. 26 released for comment a draft air permit for SunCoke Energy South Shore LLC for a new coke production plant, with a power generating component, in Greenup County.
The project company is owned by SunCoke Energy (NYSE: SXC), which has several coke production plants around the U.S., including relatively new ones in Ohio (Haverhill and Middletown) and Illinois (Granite City). The company has indicated that it is permitting a new coke plant in Kentucky, but has been somewhat vague up to now on project details.
The Greenup County facility would be on a 254-acre site, and consist of coal handling and preparation equipment, heat recovery coke ovens, coal charging, coke pushing and handling equipment, a quench tower, coke storage facilities, various administrative and support buildings, and associated air pollution control equipment. Waste heat recovery steam generators (HRSGs) and a steam turbine will be constructed to recover heat from the process gases to produce electricity.
The coking process involves heating coal in ovens to drive off volatile chemicals until only the carbon and ash remain. Unlike byproduct coking facilities which recover the volatiles and later refine them, the SunCoke facility will have heat recovery ovens, the DEP noted. This type of oven will oxidize (burn) the volatiles to produce heat for creating steam to drive steam turbines that produce electricity.
Coal would be received via barges on the river. A mobile charging/pushing machine would be loaded with the crushed coal which then charges the coal into an oven in one of the two batteries of ovens. There are 120 coke ovens arranged in two separate banks, East and West, with a combined capability of carbonizing up to 1,226,400 tons per year (tpy) of coal and producing up to 831,100 tpy of metallurgical coke.
The pushing/charging machine is equipped with a traveling hood/baghouse system to control charging emissions that escape from the negatively pressured ovens. The ovens are kept at negative pressure to minimize escape of emissions and allow the intake of additional air to aid in the carbonization process.
Once the crushed coal is loaded into an oven, the coal is heated (temperatures of 1,600°F to 2,400°F) to liberate combustible gases. The gases are pulled through sole flues, and the common tunnel, where combustion of the gas is completed to release heat and destroy some pollutants. Natural gas lances may also be used through ports to boost heat in the ovens and/or afterburner tunnel to keep them hot during maintenance activities and during extremely cold weather. The heat released from combusting the gases in the flues and tunnel is routed to HRSGs, which use the heat to create steam for running an electricity generating turbine capable of producing 40 MW-75 MW. It is possible that the natural gas lances may be needed to augment the heat going to the HRSGs in a non-routine situation requiring extra power production.
The HRSGs also serve to cool the gases to protect the downstream emission control devices placed before the main emission stack. Three HRSGs will be in use on this site to allow for maintenance/repair without direct flue gas release to atmosphere.
The coking ovens will be designed for a maximum charge of 50 tons of coal per oven on a 48-hour cycle but will also be capable of 28 tons of coal per oven on a 24-hour cycle.
SunCoke Energy, which recently spun off a master limited partnership affiliate, has been busy lately on other fronts. For example, in October 2013, the master limited partnership completed its acquisition of 100% of the ownership interest in Kanawha River Terminals LLC (KRT). KRT is a leading metallurgical and thermal coal blending and handling terminal service provider on the inland river system with the collective capacity to blend and transload more than 30 million tons of coal annually.