Azura-Edo Independent Power Plant Environmental Impact ... - IFC

With regard to coal-fired generating power, there are few reliable projections
of the potential capacity that could be (economically) extracted from this fuel
source. Having reached a peak of just 730,183 tonnes per annum in 1965, the
country’s coal production declined in the subsequent decades until, by the
early 1990s, coal production had declined to less than 100,000 tonnes per
annum. For several years, the Federal Bureau of Public Enterprises has been
trying to privatise some of the coal mines owned by the Nigerian Coal
Corporation; but it appears to have met with little success (Azura Power,
2011).
The results in Table 3.7 demonstrate that emissions from a coal-fired power
plant in comparison to an OCGT or CCGT power plant are significantly
higher for all pollutants with the exception of greenhouse gases. Based on
this; coal firing is considered the least favourable option from an air quality
perspective. Whilst the emissions from the oil-fired station are not as high as a
coal-fired station, they are significantly higher for both NO x and SO 2 than the
gas-fired options. The oil-fired scenario is also the highest emitter of
greenhouse gases, due to the higher emissions of N 2O.
Table 3.7
Fuel Alternatives Analysis
Emissions (tonnes/yr) 1,2,3,4
Base Case:
Open Cycle
Gas Turbine
(OCGT)
Power Plant
Combined
Cycle Gas
Turbine
(CCGT)
Power
Plant
Coal fired
station 5
Oil fired
station 6
Standard Pollutants
NO x 1154 697 19602 9693
CO 1577 952 5201 516
SO 2 34 20 35492 3753
Particulate Matter (PM 10/PM 2.5) 119 72 12329 132
Non-Methane Volatile Organic
Compounds (NMVOC) 136 82 2149 129
Greenhouse Gases (GHG)
CO 2 2329 1406 4071 3138
CH 4 1017 614 30 301
N 2O 65 39 34 602
CO 2(e) 43856 26470 15363 196018
1
For NOx, CO, NMVOCs, CO2, CH4, N2O emission factors from EMEP/CORINAIR Emission Inventory
Guidebook, European Environment Agency, 2007 were used.
2
For SO2 and Particulate Matter, emission factors from AP-42, Compilation of Air Pollutant Emission
Factors, US EPA, Sections 1.1 and 1.3 (updated 1998 and 2010) were used.
3
For the gas turbines, the ratio of the actual manufacturer emissions of NOx and CO for the base case were
used to scale the emissions predicted using the general emission factors.
4
To apply the emission factors, the following indicative efficiencies were assumed: 56% CCGT and 33%
coal-fired / oil-fired
5
To convert the emission factors for SO2 and Particulate Matter, a calorific value of coal was assumed of
5500 cal/g.
6
To convert the emission factors for SO2 and Particulate Matter, a calorific value of oil was assumed of 140
MMBTU/1000 US gal.
Apart from hydropower and coal-fired power, the only other major source of
base-load fuel consists of the country’s natural gas reserves. These are
currently estimated at 187 Tcf and the general industry expectation is that, for
AZURA EDO IPP
3-27
DRAFT EIA REPORT