Applications -> Stationary Source -> North America -> Gas Turbine & Boiler Industries

Gas Turbines (GT) are simply IC engines operating with rotary - rather than reciprocating – motion, comprising a compressor, combustor and power turbine. GTs are used in a wide variety of applications including electric power generation, cogeneration, natural gas transmission and various process applications. GTs using staged combustion are known as Dry Low NOx (DLN) combustors. The primary fuels used are natural gas and distillate (No.2) fuel oil.

Simple Cycle (SC)
Here the heat content of the exhaust gases exiting the GT is discarded without heat recovery, giving electrical power efficiencies of up to 58%.

Combined Cycle (CC)
Here, the GT is combined with a heat recovery steam generator (HRSG) or a steam turbine to increase the cogeneration or electrical generation efficiency respectively. In this case, efficiency increases to about 85%.

GTs used in simple cycle or combined cycle configuration have become commonplace for mid-size power generation. A popular choice of non-utility generators (NUG) and independent power producers (IPP) for cogeneration in the 1970s and 1980s, GT were dramatically embraced by US electric generating utilities in the 1990s as a more efficient, economical and practical way of generating baseload distributed power, spurred on by relatively low natural gas prices during that period. This fuel switching activity, however, saw an equally dramatic decline in the early 2000s driven by a rising natural gas price and return to more steady power demand.

The power generation industry has also had to face major structural changes following privatisation and this new business environment has led to significant investment in gas-fired combined cycle plant. In the future, lower natural gas prices and/or increased demand for power are expected to trigger a resurgence in GT use with more and more combined cycle plants brought into service. As the generating companies come under increasing competitive pressures, optimisation of plant emissions and transient/peak-shaving efficiencies in addition to base load duties will become paramount.

North America has lead the way in this field for some time now, with stringent NOx controls forcing the introduction of catalytic techniques such as CO oxidation and the selective catalytic reduction (SCR) of NOx.
As more stringent NOx regulations are introduced elsewhere across the globe, Johnson Matthey is well placed to offer unique and economical catalyst solutions to ensure emissions compliance.

Furthermore, the advent of GTs using fuel gas generated from coal gasification in Integrated Gasification Combined Cycle (IGCC) systems look set to provide a sustained market opportunity for SCR and oxidation catalyst technologies for many years to come.

Johnson Matthey SSEC offers the following catalytic technologies to control emissions from gas turbines:

For further information on IC Engine emissions control, please contact us.