The dispersion models were used to estimate or predict the concentration of air pollutants or toxins emitted from sources such as industrial plants, vehicular traffic or accidental chemical releases. In this study, the Industrial Source Complex Short Term (ISCST3) emission dispersion model was used to measure the ground level concentration of criteria air pollutants within 50 km radius of location. This model considered emissions from major point sources of pollutants in four existing and twenty-three proposed Nigeria petroleum refineries. The obtained ground level concentration for 24-hr averaging periods of the criteria air pollutants at sensitive receptor around each of the refineries was compared with the National Ambient Air Quality Standards (NAAQS) of Nigeria, World Bank and World Health Organization (WHO) to determine their level of compliance. The highest ground level concentration predicted to be 450 - 1875 μg/m 3 for 24-h averaging period was obtained at Tonwei Oil Refinery, Ekeremor Local Government, Bayelsa State, while the lowest ground level concentration predicted to be 0.0099 - 0.1 μg/m 3 for 24-h averaging period was obtained at Amakpe International Refinery, Eket Local Government, Akwa Ibom State. Percentage set limits of criteria air pollutants ranging from 0.02% to 94.5% are within the set standard limits and no health risk is associated with areas around the plant’s locations while percentage set limits of criteria pollutants ranging from 1.1 to 55.6 folds of the standards exceed the maximum permitted limits, hence affecting areas around the plants. The air quality standards guiding petroleum refinery emissions must be strictly considered, in order to ensure that the ground level concentrations do not exceed the required standard limits and prevent the adverse effects of air pollution in the Nigeria airshed.
Each year industrial facilities discharge pollutants into the environment, releasing large amounts of pollutants leading to respiratory, neurological and reproductive disorders, and cancers [
As shown in
Rivers state; Total Support Limited (12,000 bbl/day), Calabar Mnincipal local government area of Cross River state; Union Atlantic Petroleum Limited (100,000 bbl/day), Badagry local government area of Lagos state; Tonwei Oil Refinery (200,000 bbl/day), Ekeremor local government area of Bayelsa state; Ilaje Refinery and Petrochemicals (100,000 bbl/day), Ilaje local government area of Ondo state; Southwest Refinery and Petrochemical Company (100,000 bbl/day) is located in Ogun Waterside local government area of Ogun state; Owena Oil and gas Limited (100,000 bbl/day), Ilaje local government area of Ondo state [
ISCST3 model uses steady state Gaussian plume equation to model emissions from point sources, including flares, process heaters, steam boilers and fluid catalytic cracking unit. This model considered emissions from the stacks of existing refineries and proposed petroleum refineries in Nigeria. Criteria air pollutants modeled for the ground level concentration include CO, NOX, PM10, SO2 and VOC. The standards of ambient air quality as reported by NAAQS,WB and WHO is shown in
i) Control Pathway (CO): Where the modeling scenario (worst case scenario i.e. 100% operation rate), the pollutants (CO, NOX, SO2, VOC and PM) and the averaging periods (24-hr) are specified.
ii) Source Pathway (SO): Where the sources of pollutant emissions (point sources of pollutants in the refinery-process heaters, fluid catalytic cracking units, steam boilers and flares) are defined.
S/N | Pollutants | Averaging Period | Maximum Concentration (µg/m3) | ||
---|---|---|---|---|---|
NAAQS | World Bank | WHO | |||
1 | CO | 24-Hr | 11,400 | - | - |
2 | NOx | 24-Hr | 75 | 150 | - |
3 | SO2 | 24-Hr | 26 | - | 20 |
4 | PM | 24-Hr | 250 | 80 | 50 |
5 | VOC | 24-Hr | 6000 | - | - |
Source: FEPA (1991) [
Plant Name | Stack | Discharge Temperature (k) | Stack Diameter (m) | Exit Velocity (m/s) | Release Height (m) | cEmission (g/s) | ||||
---|---|---|---|---|---|---|---|---|---|---|
PM10 | SO2 | NOX | VOC | CO | ||||||
Kaduna Refining & Petrochemical Company (KRPC) 110,000 BPSD | aFlare 1 | 1540 | 6.6 | 4.52 | 66 | - | - | 0.001 | 0.003 | 0.005 |
Flare 2 | 1540 | 6.6 | 4.52 | 66 | - | - | 0.001 | 0.003 | 0.005 | |
Flare 3 | 1540 | 6.6 | 4.52 | 66 | - | - | 0.001 | 0.003 | 0.005 | |
bFCCU | 330 | 2.75 | 23.47 | 67 | - | 54.5 | 7.9 | 24.3 | 1510.4 | |
bBoiler 1 | 550 | 2.18 | 9.05 | 30 | - | 304.1 | 1420.1 | - | 106 | |
Boiler 2 | 550 | 2.18 | 9.05 | 30 | - | 304.1 | 1420.1 | - | 106 | |
Boiler 3 | 550 | 2.18 | 9.05 | 30 | - | 304.1 | 1420.1 | - | 106 | |
bHeater 1 | 660 | 2.01 | 8.03 | 43 | 2.1 | 45.1 | 173.2 | 1.0 | 15.8 | |
Heater 2 | 660 | 2.01 | 8.03 | 43 | 2.1 | 45.1 | 173.2 | 1.0 | 15.8 | |
Port Harcourt Refining Company I (PHRC) 60,000 BPSD | aFlare 1 | 840 | 1.1 | 2.47 | 36 | - | - | 0.0003 | 0.0006 | 0.002 |
Flare 2 | 840 | 1.1 | 2.47 | 36 | - | - | 0.0003 | 0.0006 | 0.002 | |
bFCCU | 180 | 1.5 | 12.8 | 37 | - | 12.5 | 2.0 | 5.6 | 347.7 | |
bBoiler 1 | 300 | 1.19 | 4.94 | 16 | - | 59.6 | 278.7 | - | 20.8 | |
Boiler 2 | 300 | 1.19 | 4.94 | 16 | - | 59.6 | 278.7 | - | 20.8 | |
bHeater 1 | 360 | 1.1 | 4.38 | 24 | 0.6 | 13.4 | 51.6 | 0.3 | 4.7 | |
Heater 2 | 360 | 1.1 | 4.38 | 24 | 0.6 | 13.4 | 51.6 | 0.3 | 4.7 | |
Port Harcourt Refining Company II (PHRC) 150,000 BPSD | aFlare 1 | 2100 | 2.75 | 6.17 | 90 | - | - | 0.002 | 0.004 | 0.01 |
Flare 2 | 2100 | 2.75 | 6.17 | 90 | - | - | 0.002 | 0.004 | 0.01 | |
Flare 3 | 2100 | 2.75 | 6.17 | 90 | - | - | 0.002 | 0.004 | 0.01 | |
Flare 4 | 2100 | 2.75 | 6.17 | 90 | 0.002 | 0.004 | 0.01 | |||
bFCCU | 450 | 3.75 | 32.01 | 92 | - | 103.5 | 14.9 | 46.3 | 2877 | |
bBoiler 1 | 750 | 2.97 | 12.35 | 41 | - | 267.8 | 1250.7 | - | 93.4 | |
Boiler 2 | 750 | 2.97 | 12.35 | 41 | - | 267.8 | 1250.7 | - | 93.4 | |
bBoiler 1 | 750 | 2.97 | 12.35 | 41 | - | 267.8 | 1250.7 | - | 93.4 | |
Boiler 2 | 750 | 2.97 | 12.35 | 41 | - | 267.8 | 1250.7 | - | 93.4 | |
bHeater 1 | 900 | 2.75 | 10.95 | 59 | 3.7 | 80.2 | 308.1 | 1.7 | 28 | |
Heater 2 | 900 | 2.75 | 10.95 | 59 | 3.7 | 80.2 | 308.1 | 1.7 | 28 |
Warri Refining & Petrochemical Company (WRPC) 125,000 BPSD | aFlare 1 | 1750 | 2.29 | 5.13 | 75 | - | - | 0.001 | 0.003 | 0.007 |
---|---|---|---|---|---|---|---|---|---|---|
Flare 2 | 1750 | 2.29 | 5.13 | 75 | - | - | 0.001 | 0.003 | 0.007 | |
Flare 3 | 1750 | 2.29 | 5.13 | 75 | - | - | 0.001 | 0.003 | 0.007 | |
Flare 4 | 1750 | 2.29 | 5.13 | 75 | 0.001 | 0.003 | 0.007 | |||
bFCCU | 375 | 3.13 | 26.68 | 76 | - | 67.3 | 9.7 | 30 | 1870.1 | |
bBoiler 1 | 625 | 2.48 | 10.29 | 34 | - | 228.8 | 1068.3 | - | 79.8 | |
Boiler 2 | 625 | 2.48 | 10.29 | 34 | - | 228.8 | 1068.3 | - | 79.8 | |
Boiler 3 | 625 | 2.48 | 10.29 | 34 | 228.8 | 1068.3 | - | 79.8 | ||
bHeater 1 | 750 | 2.29 | 9.13 | 49 | 2.9 | 61.3 | 253.3 | 1.3 | 21.4 | |
Heater 2 | 750 | 2.29 | 9.13 | 49 | 2.9 | 61.3 | 253.3 | 1.3 | 21.4 |
Source: aAbdul-Wahab et al. (2001) [
Plant Name | Stack | Discharge Temperature (k) | Stack Diameter (m) | Exit Velocity (m/s) | Release Height (m) | cEmission (g/s) | ||||
---|---|---|---|---|---|---|---|---|---|---|
PM10 | SO2 | NOX | VOC | CO | ||||||
Resource Refinery & Petrochemical, Onne 100,000BPSD | aFlare 1 | 1400 | 1.83 | 4.11 | 60 | - | - | 0.001 | 0.002 | 0.004 |
Flare 2 | 1400 | 1.83 | 4.11 | 60 | - | - | 0.001 | 0.002 | 0.004 | |
Flare 3 | 1400 | 1.83 | 4.11 | 60 | - | - | 0.001 | 0.002 | 0.004 | |
bFCCU | 300 | 2.5 | 21.34 | 61 | - | 34.7 | 5.0 | 15.6 | 965.9 | |
bBoiler 1 | 500 | 1.98 | 8.23 | 27 | - | 165.7 | 773.9 | - | 57.8 | |
Boiler 2 | 500 | 1.98 | 8.23 | 27 | - | 165.7 | 773.9 | - | 57.8 | |
bHeater 1 | 600 | 1.83 | 7.3 | 39 | 1.7 | 37.3 | 143.2 | 0.8 | 13 | |
Heater 2 | 600 | 1.83 | 7.3 | 39 | 1.7 | 37.3 | 143.2 | 0.8 | 13 | |
NSP Refineries & Oil services Limited, Andoni 120,000BPSD | aFlare 1 | 1680 | 2.2 | 4.93 | 72 | - | - | 0.001 | 0.003 | 0.006 |
Flare 2 | 1680 | 2.2 | 4.93 | 72 | - | - | 0.001 | 0.003 | 0.006 | |
Flare 3 | 1680 | 2.2 | 4.93 | 72 | - | - | 0.001 | 0.003 | 0.006 | |
Flare 4 | 1680 | 2.2 | 4.93 | 72 | 0.001 | 0.003 | 0.006 | |||
bFCCU | 360 | 3.0 | 25.61 | 73 | - | 50.1 | 7.1 | 22.3 | 1390.9 | |
bBoiler 1 | 600 | 2.38 | 10.0 | 33 | - | 238.6 | 1114.4 | - | 83.2 | |
Boiler 2 | 600 | 2.38 | 10.0 | 33 | - | 238.6 | 1114.4 | - | 83.2 | |
bHeater 1 | 720 | 2.2 | 8.76 | 47 | 2.5 | 53.7 | 206.1 | 1.1 | 18.7 | |
Heater 2 | 720 | 2.2 | 8.76 | 47 | 2.5 | 53.7 | 206.1 | 1.1 | 18.7 | |
Clean Water Refinery, Eleme (60,000BPSD | aFlare 1 | 840 | 1.1 | 2.47 | 36 | - | - | 0.0003 | 0.0006 | 0.002 |
Flare 2 | 840 | 1.1 | 2.47 | 36 | - | - | 0.0003 | 0.0006 | 0.002 | |
bFCCU | 180 | 1.5 | 12.8 | 37 | - | 12.5 | 2.0 | 5.6 | 347.7 | |
bBoiler 1 | 300 | 1.19 | 4.94 | 16 | - | 59.6 | 278.7 | - | 20.8 | |
Boiler 2 | 300 | 1.19 | 4.94 | 16 | - | 59.6 | 278.7 | - | 20.8 | |
bHeater 1 | 360 | 1.1 | 4.38 | 24 | 0.6 | 13.4 | 51.6 | 0.3 | 4.7 | |
Heater 2 | 360 | 1.1 | 4.38 | 24 | 0.6 | 13.4 | 51.6 | 0.3 | 4.7 |
RIVGAS Petroleum & Energy Limited, Port Harcourt (30,000BPSD) | aFlare 1 | 420 | 0.55 | 1.23 | 18 | - | - | 0.00007 | 0.00002 | 0.0004 | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Flare 2 | 420 | 0.55 | 1.23 | 18 | - | - | 0.00007 | 0.00002 | 0.0004 | |||
bFCCU | 90 | 0.75 | 6.4 | 18 | - | 3.1 | 0.4 | 1.4 | 87 | |||
bBoiler 1 | 150 | 0.59 | 2.47 | 8 | - | 14.9 | 69.6 | - | 5.2 | |||
Boiler 2 | 150 | 0.59 | 2.47 | 8 | - | 14.9 | 69.6 | - | 5.2 | |||
bHeater 1 | 180 | 0.55 | 2.19 | 12 | 0.2 | 3.4 | 12.9 | 0.07 | 1.2 | |||
Heater 2 | 180 | 0.55 | 2.19 | 12 | 0.2 | 3.4 | 12.9 | 0.07 | 1.2 | |||
Towei Oil Refinery 200,000 BPSD | aFlare 1 | 2800 | 3.66 | 8.22 | 120 | - | - | 0.11 | 0.20 | 0.70 | ||
Flare 2 | 2800 | 3.66 | 8.22 | 120 | - | - | 0.11 | 0.20 | 0.70 | |||
Flare 3 | 2800 | 3.66 | 8.22 | 120 | - | - | 0.11 | 0.20 | 0.70 | |||
Flare 4 | 2800 | 3.66 | 8.22 | 120 | - | 0.11 | 0.20 | 0.70 | ||||
bFCCU | 600 | 5.0 | 42.68 | 122 | - | 2158.7 | 312.85 | 962.9 | 60,006 | |||
bBoiler 1 | 1000 | 3.96 | 16.46 | 54.3 | - | 23,040 | 107605.4 | - | 8,033.4 | |||
Boiler 2 | 1000 | 3.96 | 16.46 | 54.3 | - | 23,040 | 107605.4 | - | 8,033.4 | |||
Boiler 3 | 1000 | 3.96 | 16.46 | 54.3 | - | 23,040 | 107605.4 | - | 8,033.4 | |||
Boiler 4 | 1000 | 3.96 | 16.46 | 54.3 | - | 23,040 | 107605.4 | - | 8,033.4 | |||
bHeater 1 | 1200 | 3.66 | 14.6 | 78.6 | 229.86 | 5183.0 | 19904.66 | 107.7 | 1,811.1 | |||
Heater 2 | 1200 | 3.66 | 14.6 | 78.6 | 229.86 | 5183.0 | 19904.66 | 107.7 | 1,811.1 | |||
Orient Petroleum Resource Limited 55,000 BPSD | aFlare 1 | 770 | 1.01 | 2.26 | 33 | - | - | 0.001 | 0.03 | 0.04 | ||
Flare 2 | 770 | 1.01 | 2.26 | 33 | - | - | 0.001 | 0.03 | 0.04 | |||
bFCCU | 165 | 1.38 | 11.74 | 34 | - | 368.48 | 55.62 | 163.3 | 10,167 | |||
bBoiler 1 | 275 | 1.09 | 4.53 | 15 | - | 1741.5 | 8137.76 | - | 608.33 | |||
Boiler 2 | 275 | 1.09 | 4.53 | 15 | - | 1741.5 | 8137.76 | - | 608.33 | |||
bHeater 1 | 330 | 1.01 | 4.02 | 22 | 17.38 | 392.81 | 1505.19 | 10.43 | 139.05 | |||
Heater 2 | 330 | 1.01 | 4.02 | 22 | 17.38 | 392.81 | 1505.19 | 10.43 | 139.05 | |||
Amakpe Internatna Refinery 12,000 BPSD | aFlare 1 | 168 | 0.22 | 0.49 | 7 | - | - | 0.0004 | 0.001 | 0.003 | ||
Flare 2 | 168 | 0.22 | 0.49 | 7 | - | - | 0.0004 | 0.001 | 0.003 | |||
bFCCU | 36 | 0.3 | 2.56 | 7 | - | 13.70 | 2.43 | 10.43 | 483.19 | |||
bBoiler 1 | 60 | 0.24 | 0.98 | 3 | - | 560.05 | 2602.24 | - | 209.24 | |||
Boiler 2 | 60 | 0.24 | 0.98 | 3 | - | 560.05 | 2602.24 | - | 209.24 | |||
bHeater 1 | 72 | 0.22 | 0.88 | 5 | 1.05 | 1.05 | 73.00 | 0.35 | 0.69 | |||
Heater 2 | 72 | 0.22 | 0.88 | 5 | 1.05 | 1.05 | 73.00 | 0.35 | 0.69 | |||
Chase wood Consortiu Nigeria Limited 70,000 BPSD | aFlare 1 | 980 | 1.28 | 2.88 | 42 | - | - | 0.01 | 0.03 | 0.07 | ||
Flare 2 | 980 | 1.28 | 2.88 | 42 | - | - | 0.01 | 0.03 | 0.07 | |||
bFCCU | 210 | 1.75 | 14.94 | 43 | - | 590.95 | 83.42 | 264.1 | 13.90 | |||
bBoiler 1 | 19 | 350 | 1.39 | 19 | - | 2930.4 | 13678.8 | - | 983.8 | |||
Boiler 2 | 19 | 350 | 1.39 | 19 | - | 2930.4 | 13678.8 | - | 983.8 | |||
bHeater 1 | 420 | 1.28 | 5.11 | 28 | 31.28 | 636.14 | 2436.81 | 13.90 | 222.48 | |||
Heater 2 | 420 | 1.28 | 5.11 | 28 | 31.28 | 636.14 | 2436.81 | 13.90 | 222.48 | |||
Source: aAbdul-Wahab et al. (2001); bStell (2000); cUSEPA (1989).
iii) Receptor Pathway (RE): where the receptors which determine the air quality impact at specific locations. Specifically, 50 km radius within each refinery was given adequate attention.
iv) Meteorological Pathway (ME): Where the atmospheric condition of the areas being modeled is defined, so it can be taken into account when determining the distribution of air pollution impacts for the area. Due to lack of upper air observations in Nigeria airport, meteorological database for the project location was combined using data from Cotonou meteorological observations. Cotonou has winds having prevalence for a southwesterly direction which is consistent with the winds observed in the refineries.
v) Terrain Grid Pathway (TG): Where the option of gridded terrain data to be used in calculating dry depletion in elevated or complex terrain is specified. Elevated terrain is relevant to this study.
(vi) Output Pathway (OU): Where you define which output results are necessary to meet the needs of the air quality modeling analysis. The resultant output is the ground level concentration of pollutants as shown in
From the existing and proposed refineries, the ground level concentration (glc) of the criteria air pollutant were computed and compared with the standards of ambient air quality derived from National Ambient Air Quality Standards (NAAQS) of Federal Ministry of Environment (FMENV), that of the World Bank environmental guidelines and World Health Organization (WHO) standards to determine their level of compliance (
An air quality impact on refineries is important to assess the impacts of emissions from petroleum refinery operations on their environment.
S/N | Refinery | Air Pollutant | Maximum glc (µg/m3) | Maximum Impact Local Government Area | % Set Limit of FMENV, WB, WHO |
---|---|---|---|---|---|
1 | Kaduna Refining & Petrochemical Company (KRPC) 110,000 BPSD | PM10 | 0.4 | Chikun | 0.2 |
SO2 | 82.7 | Chikun | 3.2a | ||
NOx | 404.9 | Chikun | 5.4a | ||
CO | 164.1 | Chikun | 1.4 | ||
VOC | 2..3 | Chikun | 0.04 | ||
2 | Port Harcourt Refining Company I (PHRC) 60,000 BPSD | PM10 | 0.2 | Eleme | 0.08 |
SO2 | 26.3 | Eleme | 1.02a | ||
NOx | 121.4 | Eleme | 1.6a | ||
CO | 73.0 | Eleme | 0.6 | ||
VOC | 1.0 | Eleme | 0.02 | ||
3 | Port Harcourt Refining Company II (PHRC) 150,000 BPS | PM10 | 0.7 | Eleme | 0.3 |
SO2 | 111.9 | Eleme | 4.3a | ||
NOx | 3,589.1 | Eleme | 4.7a | ||
CO | 214.9 | Eleme | 1.9 | ||
VOC | 17.6 | Eleme | 0.3 | ||
4 | Warri Refining & Petrochemical Company (WRPC) 125,000 BPSD | PM10 | 1.7 | Warri S/W | 0.7 |
SO2 | 444.4 | Warri S/W | 1.7a | ||
NOx | 2,145.8 | Warri S/W | 2.9a | ||
CO | 479.2 | Warri S/W | 4.2 | ||
VOC | 0.9 | Warri S/W | 0.1 |
afolds of % set limits of the standard i.e. above the set standard limits.
(surface plots available on request) while the Tables showing the results of maximum ground Level Concentration of air pollutant within 50 km from each of the refineries are shown in
The ISCST3 dispersion model has been used in this study to evaluate the ground level concentrations from the
S/N | Refinery | Air Pollutant | Maximum glc (µg/m3) | Maximum Impact Local Government Area | % Set Limit of FMENV, WB, WHO |
---|---|---|---|---|---|
1 | Amakpe International Refinery (12,000 bpsd) | PM10 | 0.04 | Ikot Ekpene | 0.02 |
SO2 | 4.4 | Ikot Ekpene | 16.9 | ||
NOx | 22.6 | Ikot Ekpene | 30.1 | ||
CO | 10.7 | Ikot Ekpene | 0.04 | ||
VOC | 0.2 | Ikot Ekpene | 0.002 | ||
2 | Amexum Corporation (100,000 bpsd) | PM10 | 0.5 | Akpabuyo | 0.2 |
SO2 | 6.7 | Akpabuyo | 0.4 | ||
NOx | 314 | Akpabuyo | 0.4a | ||
CO | 215 | Akpabuyo | 1.9 | ||
VOC | 4.1 | Akpabuyo | 0.1 | ||
3 | Antonio Oil (27,000 bpsd) | PM10 | 0.5 | Ipokia | 0.2 |
SO2 | 99.4 | Ipokia | 3.8a | ||
NOx | 413 | Ipokia | 1.5 | ||
CO | 37.5 | Ipokia | 0.3 | ||
VOC | 1.8 | Ipokia | 0.03 | ||
4 | Chase Wood Consortium Nigeria Limited (70,000 bpsd) | PM10 | 0.5 | Eket | 0.2 |
SO2 | 210 | Eket | 0.8a | ||
NOx | 1500 | Eket | 2.0a | ||
CO | 170 | Eket | 0.01 | ||
VOC | 26 | Eket | 0.4 | ||
5 | Clean Water Refinery (60,000 bpsd) | PM10 | 0.5 | Eleme | 0.2 |
SO2 | 39.5 | Eleme | 1.3a | ||
NOx | 185.5 | Eleme | 2.0a | ||
CO | 102.4 | Eleme | 0.9 | ||
VOC | 1.6 | Eleme | 0.02 | ||
6 | Gasoline Associate & International Limited Refinery (100,000 bpsd | PM10 | 0.5 | Ipokia | 0.2 |
SO2 | 58.6 | Ipokia | 2.3a | ||
NOx | 281.5 | Ipokia | 3.8a | ||
CO | 139.8 | Ipokia | 1.2 | ||
VOC | 2.1 | Ipokia | 0.04 | ||
7 | Ilaje Refinery & Petrochemicals (100,000 bpsd) | PM10 | 0.8 | Ilaje | 0.3 |
SO2 | 61 | Ilaje | 0.2a | ||
NOx | 298 | Ilaje | 3.9a | ||
CO | 192 | Ilaje | 1,7 | ||
VOC | 3.0 | Ilaje | 0.05 |
8 | Niger Delta Refinery & Petrochemical Limited (100,000 bpsd) | PM10 | 0.5 | Warri South | 0.2 |
---|---|---|---|---|---|
SO2 | 72.7 | Warri South | 2.8a | ||
NOx | 347.3 | Warri South | 4.6a | ||
CO | 417.1 | Warri South | 3.7 | ||
VOC | 6.7 | Warri South | 0.1 | ||
9 | NSP Refineries and Oil Services Limited (120,000 bpsd) | PM10 | 0.9 | Andoni | 0.4 |
SO2 | 395.0 | Andoni | 1.5a | ||
NOx | 1903.0 | Andoni | 1.3a | ||
CO | 375.0 | Andoni | 3.3 | ||
VOC | 6.0 | Andoni | 0.1 |
10 | Ode Aye Refinery Limited (100,000 bpsd) | PM10 SO2 | 0.4 83.5 | Okiti pupa Okiti pupa | 0.2 32.1a |
---|---|---|---|---|---|
NOx | 440 | Okiti pupa | 5.9a | ||
CO | 113.8 | Okiti pupa | 1.0 | ||
VOC | 2.0 | Okiti pupa | 0.03 | ||
11 | Ologbo Refinery Company Nigeria Limited (12,000 bpsd) | PM10 | 0.05 | Ikpoba-oha | 0.02 |
SO2 | 0.9 | Ikpoba-oha | 3.5a | ||
NOx | 8.9 | Ikpoba-oha | 11.8 | ||
CO | 5.0 | Ikpoba-oha | 0.04 | ||
VOC | 0.1 | Ikpoba-oha | 0.002 | ||
12 | Orient Petroleum Resources Limited (55,000 bpsd) | PM10 | 0.7 | Anambra West | 0.3 |
SO2 | 0.9 | Anambra West | 3.5 | ||
NOx | 8.5 | Anambra West | 11.3 | ||
CO | 219.6 | Anambra West | 1.9 | ||
VOC | 3.0 | Anambra West | 0.01 | ||
13 | Owena Oil & Gas Limited (60,000 bpsd) | PM10 | 0.2 | Ilaje | 0.08 |
SO2 | 34.5 | Ilaje | 13.3a | ||
NOx | 159.4 | Ilaje | 2.2a | ||
CO | 78 | Ilaje | 0.7 | ||
VOC | 1.2 | Ilaje | 0.02 | ||
14 | Qua Petroleum Refinery Limited (100,000 bpsd) | PM10 | 1.0 | Ibeno | 0.4 |
SO2 | 142.5 | Ibeno | 24.0a | ||
NOx | 623 | Ibeno | 8.3a | ||
CO | 423 | Ibeno | 3.7 | ||
VOC | 6.5 | Ibeno | 0.1 |
15 | Rehoboth Natural Resources Limited (12,000 bpsd | PM10 | 0.05 | Yenegoa | 0.02 |
---|---|---|---|---|---|
SO2 | 2.4 | Yenegoa | 92.3 | ||
NOx | 12.1 | Yenegoa | 16.1 | ||
CO | 9.7 | Yenegoa | 0.1 | ||
VOC | 0.2 | Yenegoa | 0.003 | ||
16 | Resources Refinery & Petrochemical Limited (100,000 bpsd) | PM10 | 1.3 | Ikot Abasi | 0.7 |
SO2 | 191.2 | Ikot Abasi | 8.6a | ||
NOx | 897.3 | Ikot Abasi | 14.8a | ||
CO | 399.4 | Ikot Abasi | 5.8 | ||
VOC | 6.0 | Ikot Abasi | 0.2 | ||
17 | RIVGAS Petroleum & Energy Limited (30,000 bpsd) | PM10 | 0.3 | Port Harcourt | 0.1 |
SO2 | 0.4 | Port Harcourt | 1.5 | ||
NOx | 112.3 | Port Harcourt | 1.5a | ||
CO | 3.9 | Port Harcourt | 0.03 | ||
VOC | 1.8 | Port Harcourt | 0.02 | ||
18 | Sapele Refinery Limited (100,000 bpsd) | PM10 | 0.3 | Sapele | 0.1 |
SO2 | 48.9 | Sapele | 18.8a | ||
NOx | 255.2 | Sapele | 3.4a | ||
CO | 48.9 | Sapele | 0.4 | ||
VOC | 1.6 | Sapele | 0.03 |
19 | South West Refinery & Petrochemical Company (100,000 bpsd) | PM10 SO2 | 0.7 59.4 | Ogun water side Ogun water side | 0.3 22.8a |
---|---|---|---|---|---|
NOx | 270 | Ogun water side | 3.6a | ||
CO | 149.8 | Ogun water side | 1.3 | ||
VOC | 2.4 | Ogun water side | 0.04 | ||
20 | Starrex Petroleum Refinery (100,000 bpsd) | PM10 | 1.0 | Eleme | 0.4 |
SO2 | 0.4 | Eleme | 1.5 | ||
NOx | 112.3 | Eleme | 1.5a | ||
CO | 3.9 | Eleme | 0.03 | ||
VOC | 1.8 | Eleme | 0.03 | ||
21 | Towei Oil Refinery (200,000 bpsd) | PM10 | 1.5 | Ekeremor | 0.6 |
SO2 | 376 | Ekeremor | 1.0a | ||
NOx | 1875.4 | Ekeremor | 2.5a | ||
CO | 168.9 | Ekeremor | 1.5 | ||
VOC | 1.6 | Ekeremor | 0.03 |
22 | Total Support Limited (12,000 bpsd) | PM10 | 0.7 | Calabar Municipal | 0.3 |
---|---|---|---|---|---|
SO2 | 2.9 | Calabar Municipal | 6.2a | ||
NOx | 16 | Calabar Municipal | 21.3 | ||
CO | 22 | Calabar Municipal | 0.2 | ||
VOC | 0.5 | Calabar Municipal | 0.01 | ||
23 | Union Atlantic Petroleum Refinery (100,000 bpsd) | PM10 | 1.8 | Badagry | 0.7 |
SO2 | 224 | Badagry | 86.2a | ||
NOx | 116.8 | Badagry | 1.6a | ||
CO | 658 | Badagry | 5.8 | ||
VOC | 10.3 | Badagry | 0.2 |
afolds of % set limits of the standard (above the set standard limit).
S/N | Refinery | Air Pollutant | Cumulative Maximum glc (µg/m3) | % Set Limit of FMENV, WB, WHO |
---|---|---|---|---|
1 | Rehoboth Natural Resources Limited & Towei Oil Refinery Bayelsa State | PM10 | 1.5 | 0.6 |
SO2 | 376 | 14.5a | ||
NOx | 1875.4 | 25.0a | ||
CO | 168.9 | 1.5 | ||
VOC | 1.6 | 0.03 | ||
2 | Total Support Limited & Amexum Corporation Cross River State | PM10 | 0.5 | 0.2 |
SO2 | 7.0 | 2.7a | ||
NOx | 314.4 | 4.2a | ||
CO | 215 | 1.9 | ||
VOC | 2.3 | 0.1 | ||
3 | Antonio Oil, South West Refinery & Gasoline International Limited Refinery Ogun State | PM10 | 4.6 | 1.8 |
SO2 | 107.4 | 4.1a | ||
NOx | 426.4 | 5.7a | ||
CO | 149.8 | 1.7a | ||
VOC | 2.6 | 0.04 | ||
4 | Ode Aye Refinery Limited, Ilaje Refinery & Petrochemicals & Owena Oil & Gas Limited Ondo state | PM10 | 0.8 | 0.3 |
SO2 | 84.5 | 3.3a | ||
NOx | 444.5 | 5.9a | ||
CO | 199.5 | 1.8 | ||
VOC | 3.0 | 0.05 | ||
5 | Warri Refining, Niger Delta Refinery & Sapele Refinery Limited Delta State | PM10 | 1.7 | 0.7 |
SO2 | 443.3 | 17.1a | ||
NOx | 2145.8 | 28.6a | ||
CO | 480.3 | 4.2 | ||
VOC | 7.0 | 0.1 |
6 | Amakpe International Refinery, Chase Wood Consortium Nigeria Limited, Resources Refinery & Qua Petroleum Refinery Limited Akwa Ibom State | PM10 | 8.0 | 3.2 |
---|---|---|---|---|
SO2 | 501 | 19.3a | ||
NOx | 2214 | 29.5a | ||
CO | 480.3 | 3.7 | ||
VOC | 7.0 | 0.4 | ||
7 | Clean Water Refinery, NSP Refineries and Oil Services Limited, RIVGAS Petroleum & Energy Limited, Starrex Petroleum Refinery, Port Harcourt Refining Company I & Port Harcourt Refining Company II River state | PM10 | 0.2 | 0.4 |
SO2 | 204 | 7.8a | ||
NOx | 957 | 12.8a | ||
CO | 1.6 | 3.5 | ||
VOC | 0.1 | 0.1 |
a folds of % set limits of the standard i.e. above the set standard limit.
four existing refineries and twenty-three proposed refineries in Nigeria for the purpose of predicting the air quality impact. Emissions from minimum of seven and maximum of eleven elevated point sources of criteria pollutants with “worst case” scenario were considered. The 24-hr averaging period of ground level concentration was measured and compared with the Nigeria’s ambient quality air set limits as set by National Ambient Air Quality Standard (NAAQS), World Bank and World Health Organization (WHO) within 50 km receptor locations.
From the modeling outputs, NOx and SO2 are the major pollutants that exceed the set limit, hereby causing harmful effects to the environment while PM, NOx and VOCs are within the set standard and have no effect on the environment. The highest ground level concentration predicted to be 450 - 1875 µg/m3 for 24-h averaging period was obtained at Tonwei Oil Refinery, Ekeremor Local Government, Bayelsa State, proposed to operate at installed capacity 200,000 barrels/day capacity while the lowest ground level concentration predicted to be 0.0099 - 0.1 µg/m3 for 24-h averaging period was obtained at Amakpe International Refinery, Eket Local Government, Akwa Ibom State, proposed to operate at installed capacity 12,000 barrels/day. According to Ambient Air Quality Standards (AAQS), percentage set limits of criteria air pollutants ranging from 0.02% - 94.5% are within the set standard limits and no health risk is associated with areas around the plant locations while percentage set limits of criteria pollutants ranging from 1.1 - 55.6 folds of the standards exceed the maximum permitted limits and health risk is associated with areas around the plant locations as stipulated by the National Ambient Air Quality Standard (NAAQS), World Bank and World Health Organization (WHO) emission set standards.
The study reveals that the contribution of emissions from criteria pollutant to its ambient air is significant. Possible impacts of anticipated emissions of criteria pollutants on humans [