Page 235 - Sustainable On-Site CHP Systems Design, Construction, and Operations

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emission control systems. Environment Canada, the Canadian equivalent of U.S. EPA,
issued NO guidelines for stationary turbines that allow credit for heat recovery and
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generally reflect the use of reasonable technology, without the use of post-combustion
emission control devices. The United Kingdom, Australia, Germany, and many other
national governments enforce minimum emission standards for gas turbines that can
be met without the use of post-combustion emissions control technology. The U.S. NSPS
for stationary gas turbines also allows one to waive the use of post-combustion emis-
sion controls. Year 2006 amendments to NSPS for power generating gas turbines rated
at 3 to 50 MW include a NO standard of 42 ppmv (parts per million by volume) at
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15 percent O or 2.3 lb/MW-h.
2
Other national and international organizations also specify minimum standards for
reciprocating internal combustion engines to qualify for funding opportunities. USAID
funds and oversees many projects in developing countries and requires that recipro-
cating internal combustion engines meet the minimum NSPS standards that would
apply to projects located in the United States. The United Nations and the World Bank
also place minimum emission and performance standards on various projects that they
sponsor.
The technology standards outlined above are only minimum standards. In many
cases, local permitting agencies may require that more stringent technology or emission
standards be met due to regional environmental conditions or project-specific circum-
stances. For example, while U.S. NSPS provides for the installation of a natural gas
lean burn engine or a natural gas turbine with no additional emissions controls, local
permitting agencies may require the installation of an SCR system to control NO
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emissions by 90 percent and an oxidization catalyst to control ROG and CO emis-
sions by 50 to 85 percent. Even the U.S. EPA requires much more stringent standards
known as best available control technology (BACT) or lowest achievable emission rate
(LAER) for certain large facilities and for projects in areas that do not meet national
ambient air quality standards.
The concept of tailoring more stringent standards to meet local environmental
challenges is not unique to the United States. Even though Environment Canada offers
gas turbine installation guidelines, local provinces also regulate the installation of gas
turbines. The Province of Alberta requires that new natural gas–fired turbines rated
below 20 MW meet a NO limit of 0.6 g/MW-h. These standards reflect newer engine
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technology than is suggested in national guidelines, but can still be met without the
use of post-combustion emission controls. The Alberta standards are applied to a
project located in the province, regardless of the guidelines that are issued by Envi-
ronment Canada.
Technology Assessment Tools and Methods
Because technology changes rapidly, it is not feasible to publish and identify current
local requirements that may apply in all situations. While minimum technology or
emission standards tend to be specified in fairly static regulations or policy statements,
more stringent standards that may be enforced as BACT or LAER, or that may other-
wise be mandated by permitting agencies, tend to be less static and therefore cannot
easily be specified in formal regulations. When initiating discussions with local permit-
ting agencies, the project engineer or developer should inquire about all emission and
technology standards that may be mandated by the agency or by other local environ-
mental agencies.