Texas nears air permit decision for Neches Station project of Apex Texas

Apex Texas Power LLC is nearing a final decision from the Texas Commission on Environmental Quality (TCEQ) for issuance of Proposed Air Quality Permit Number 122401 and Prevention of Significant Deterioration Air Quality Permit Number PSDTX1428, which would authorize construction of the Neches Station in Cherokee County, Texas.

The commission said in a Nov. 6 notice, posted to its website on Nov. 10, that its executive director has completed the technical review of the application and prepared a draft permit which, if approved, would establish the conditions under which the facility must operate.

This permit would authorize the following:

Scenario 1 – four natural gas fired combustion turbines (CTGs) to operate in simple cycle from the following options: four Siemens Model F5 turbines, each rated at nominal capability of 232 MW; or four General Electric GE 7FA turbines, each rated at nominal capability of 220 MW.

Scenario 2 – two natural gas fired CTGs to operate in either simple or combined cycle under the following options:

  • two Siemens Model F5 turbines, each rated at nominal capability of 232 MW. Each CTG will have a duct fired heat recovery steam generator (HRSG) with a maximum heat input of 532 million British thermal units per hour (MMBtu/hr); or
  • two General Electric Model GE 7FA turbines, each rated at nominal capability of 220 MW. Each CTG will have a duct fired heat recovery steam generator (HRSG) with a maximum heat input of 459 million British thermal units per hour (MMBtu/hr).

Apex Texas Power plans to construct and operate the Neches Station near Cuney in Cherokee County. The ancillary equipment includes an auxiliary boiler, a firewater pump, cooling tower, and various support facilities. The CTGs will be fueled with pipeline quality natural gas.

The CTGs will use an aqueous ammonia-based selective catalytic reduction (SCR) system to control nitrogen oxides (NOx) emissions. The system will be comprised of aqueous ammonia (NH3) storage and handling equipment, an NH3 vaporizer, an NH3 injection grid, and catalyst bed modules. The NH3 injection grids and the SCR catalyst beds will be installed in the HRSG housings at locations where exhaust temperatures will promote the NOx reduction reactions.

The aqueous NH3 will be delivered by tanker truck, which will use vapor balance to capture emissions during filling of the storage tanks. In addition, the aqueous NH3 will be stored in pressurized tanks equipped with pressure relief valves to prevent emissions. However, piping and fittings associated with the tanks and the transfer of NH3 throughout the system will be sources of fugitive emissions.

The natural gas-fired auxiliary boiler will have a maximum heat input of 108.4 MMBtu/hr. The boiler will provide system steam requirements.

A condenser/cooling tower arrangement will be utilized to cool steam exhausted from each turbine train. The condenser will be a surface contact heat exchanger and the cooling tower will be a multi-cell motor driven, mechanical draft, counter-flow tower with film fill. The tower will have a 160,000 gallon per minute circulation rate and a drift eliminator design of 0.0005%.

The site will be equipped with one firewater pump. The engine running this equipment will fire ultra-low sulfur diesel fuel, containing no more than 15 parts per million (ppm) sulfur by weight. The firewater pump is limited to 100 hours of non-emergency operation per calendar year.

A listed project contact is: Apex Texas Power LLC, Kent D Mathews, Project Manager, (512) 569-5084.

Said the website of Apex Power Group LLC about this project, which has a 2017 commercial operations target year: “Apex Texas Power is developing Neches Station to support system reliability needed for the growth of wind and other renewable generation resources. The plant will be sized from 450 MW to 900 MW of quick start, efficient, gas fired combustion turbines that are capable of reaching full output in 13 minutes!”

The Apex website also says: “Apex Power Group, LLC was formed in 2007 after the Principals had worked together on development of Panoche Energy Center. The team formed an instant connection and found that our strengths and abilities were comprehensive and complimentary for the ongoing development of power projects. Gary Chandler, David Jenkins and Michael King leveraged their significant Power and Electric Utility experience to form Apex Power Group. We now have a combined power experience exceeding 100 years.”

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.