Maxim swaps 520-MW gas project for abandoned 500-MW coal facility

The Alberta Utilities Commission on March 18 went out for comment on a November 2013 application by Maxim Power Corp. to amend its approval for the HR Milner expansion project in the Grande Cache area of this Canadian province.

Maxim is proposing to construct a 520-MW natural gas-fired power plant next to its existing Milner coal plant, instead of the previously approved 500-MW coal-fired addition. Maxim currently operates a 150-MW coal-fired plant known as the HR Milner facility. In August 2011, Maxim received AUC approval to expand the HR Milner site with the construction of the new 500-MW coal facility.

“New federal greenhouse gas (GHG) emissions legislation was introduced in September 2012 that requires stringent performance standards for coal-fired generators,” said the application. “The standards are fixed at 420 tonnes of carbon dioxide per gigawatt hour (CO2/GWh) to be met by new coal-fired generators by July 1, 2015. Given the new standards and MAXIM’s commitment to reduce the environmental effects of their operations, MAXIM altered the plans for the M2 Project. Rather than building the 500 MW coal-fired power plant, MAXIM is planning to build and operate a natural gas fired plant with lower GHG emissions. The current low price in natural gas makes this a financially feasible option.”

MAXIM plans to build M2 in two phases with the construction of two 260-MW combined-cycle gas turbine (CCGT) power plants. Natural gas will be supplied to the Milner Site via an expansion of the existing natural gas pipeline currently supplying the existing M1 unit. Each phase will consist of the construction of the following:

  • Gas turbine generator;
  • Heat recovery steam generator;
  • Steam turbine generator; and
  • Ancillary systems to support these major systems.

The first phase will also include the construction of a water treatment plant, a cooling tower and an electrical substation, all of which will be used by both plants.

TransCanada Pipelines the likely gas supplier

The revamped M2 project will use natural gas as fuel for the industrial gas turbines. During times when both CCGT plants are out of service, natural gas will also be burned in auxiliary boilers to produce steam to satisfy equipment start-up and building heating needs. MAXIM said it has been indiscussions with TransCanada Pipelines Ltd. to construct, operate and own the pipeline.

Each CCGT plant will have one packaged industrial gas turbine-generator. The data in the amendment application was obtained from performance modeling based on a General Electric 7FA.04 (3-Series). A competitive bidding process will determine the actual make and model used during the initial stage of implementing the M2 Project, the application added.

Integral to the HRSG is a selective catalytic reduction (SCR) system that is used to reduce the NOx emissions further in the flue gas. The SCR consists of a ceramic catalyst located in the flue gas stream. A gaseous reductant (namely aqueous ammonia) is injected into the flue gas stream, and reacts with the catalyst to reduce the NOx emissions. External to the HRSG is the aqueous ammonia storage tank, pumping system, a vaporizer, fan, air heater and mixing chamber.

The steam turbine for M2 will be designed to handle high, intermediate and low-pressure steam supplied from its associated HRSG. Each section will have a rotor fitted with turbine blades rotating within a casing that contains static blades. Steam expanding through the turbine blades is converted to shaft energy, which drives an electric generator. When producing electricity, steam turbine rotors will rotate at a constant rate of 3,600 rpm.

The project contact is: Maxim Power Corp., Jim Pollock, Phone: (403) 263-3021, Email:

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.