Developer nears permits for 1,350-MW gas plant in Indiana

St. Joseph Energy Center LLC (SJEC) is proposing a nominal 1,350-MW combined cycle combustion turbine (CCCT) power plant in New Carlisle, Ind., with the state Department of Environmental Management currently taking public comment on draft air permits for the project.

IDEM plans an Oct. 4 public meeting and hearing in New Carlisle on the draft permits as the final stage in the public comment process.

This facility will include two natural gas-fired 2×1 CCCT blocks and ancillary equipment. A water treatment facility will be constructed on-site to supply SJEC operations. The water treatment facility will be operated by the town of New Carlisle, but is considered as part of the CCCT facility.

SJEC submitted a Prevention of Significant Deterioration and Title V Operating Permit application to IDEM in October 2011. The facility will include four natural gas-fired combined cycle combustion turbines, each equipped with dry low NOx burners, natural gas fired duct burners, and a heat recovery steam generator. NOx emissions are to be controlled by four selective catalytic reduction systems, and CO and VOC emissions are to be controlled by oxidation catalyst systems. The nominal heat input for each CCCT is 2,300 MMBtu/hr (higher heating value (HHV)). The combined nominal power output is 1,350 MW.

There will also be two natural gas fired auxiliary boilers, each with a maximum heat input capacity of 80 MMBtu/hr (HHV), equipped with low NOx burners with flue gas recirculation to reduce NOx emissions. And there will be one emergency diesel generator, nominally rated at 2,012 horsepower.

The draft permit noted that SJEC will use F class combustion turbines, not the more efficient G class turbines. “The ‘G’ class combustion turbines differ from ‘F’ in two important ways: a) the combustors fire at substantially higher temperatures; which fundamentally is the reason ‘G’ machines have a somewhat higher thermal efficiency and b) the commercially available equipment is rated at 250 MW nominal each unit,” said the draft permit. “The larger 250 MW unit rating does not fit the 600 MW power block capacity. A “2 on 1” configuration would be too large at 750 MW and a “1 on 1” too small at 400 MW.”

The draft permit added: “Also, the higher thermal efficiency ‘G’ machines are primarily designed to operate more frequently at a steady base loaded condition and not be cycled up and down in MW load or on and off frequently. The ‘F’ class machines are more thermally flexible and the power blocks more responsive to varying market demand and unit load cycling operation. Based on the available interconnection with the local grid, the maximum load requirements established by near term market demand, and the need to respond quickly to frequent changes in power demand, use of ‘G’ class combustion turbines are not suitable for this project and SJEC will utilize commercially proven F-class turbines.”

A local media report on from March 2011 shows this is the third power project proposed for this same site, following a coal gasification project at one time proposed by TONDU and a gas-fired plant that was being developed last decade by Allegheny Energy. The current SJEC project is being backed by Development Partners out of White Plains, N.Y. A fact sheet distributed locally at that time said the project will help replace a number of Midwest coal-fired power plants due for retirement.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.