Environmental Engineering Reference
In-Depth Information
In the following part, we will introduce the process and results of the sampling
tests of the above-mentioned typical coal-fired power plants using the Ontario
Hydro method (OH Method, U.S. Standard Mercury Sampling Method), Con-
tinuous Emission Monitor (CEM) method, and 324 method. We also discuss the
distribution of mercury speciation in flue gas from coal-fired power plants as well
as the impact of various air pollutant control devices on mercury speciation.
2.2 Mercury Measurement Method in Coal-Fired Power Plants
Many mercury measurement methods are being used in the study of mercury
emissions, but many among these are still being studied. These methods can be
divided into two kinds: the manual analysis method and the on-line analysis me-
thod, which is also called CEM. Depending on the test procedure and the measuring
method, the manual analysis methods can be further divided into the wet chemical
and the dry adsorption methods. The manual analysis requires a longer time, whe-
reas the on-line analytical technique can analyze mercury concentration and speci-
ation in real-time.
2.2.1 Manual Analysis Method
There are two kinds of wet chemical mercury testing methods: the measurement
method of total mercury (for example, the EPA 101A method and EPA 29 method,
etc.) and the measurement method of mercury speciation (for example, the OH
method, the Tris Buffer method, and the EPA 101B method, etc.). Dry sorbent
methods usually refer to the flue gas mercury sorbent speciation (FMSS) and the
quicksilver emissions monitor (QSEM).
The OH method is the choice of over 80 American coal-fired power plants for
measuring mercury concentration and speciation. However, it is very complex for
mercury sampling and analyzing in the coal-fired flue gas testing field. Many fac-
tors, such as coal type, fly ash, gas velocity, temperature, and so on, can directly
affect the accuracy and reliability of the test data. The mass balance of test results
can also reflect the reliability of the sampling analysis of mercury from coal-fired
power plants. According to Takahisa's research, it is acceptable for the mass bal-
ance to be within the range of 70% - 130% [1] .
2.2.2 Continuous Emission Monitoring
CEM is a developing technology that can conduct real-time monitoring and analy-
sis. It is based on advanced analysis technology, such as cold atomic absorption
Search WWH ::




Custom Search