Gas Flare Site Research Articles

Gas flares contribution in total health risk assessment of BTEX in Asalouyeh, Iran

The health risk assessment of benzene, toluene, ethylbenzene and xylenes (BTEX) associated with the combustion of gas in gas flares of one of the largest gas refinery complex in Iran (South Pars gas complex in Asalouyeh, 1–10 phases) has been conducted based on Office of Environmental Health Hazard Assessment’s (OEHHA) method. In this regard, AERMOD dispersion model coupled with WRF model has been used to predict the ground level concentration of pollutants emitted from gas flares. The accuracy of the dispersion model has been verified with measured ambient SO2 data. The risk assessment results have shown that the chronic noncarcinogenic risk of BTEX emitted from gas flares is in the acceptable range in the residential area and most of refineries site. Regarding acute noncarcinogenic risk, the hazard indices (HIs) are only greater than one in refineries sites and are less than permitted level elsewhere in the study area. For carcinogenic risk, the cumulative risk of benzene and ethylbenzene are greater than 10−6 in refineries sites and two cities (Asalouyeh and Nakhl Taghi), but in two camps nearby the gas flaring sites, the value is less than the allowable limit. Besides, the relative contribution of gas flaring in health risk assessment of BTEX is accomplished by calculating the health risk parameters with the measured BTEX concentrations at 10 receptors, which reveal the cumulative effects of all potential sources of BTEX throughout the study area. The comparison of health risk parameters has shown that the health risk of BTEX associated with flaring is in average 42 %, 2.6 % and 10.8 % of the overall health risk of BTEX in industrial areas, two cities and camps, respectively. It can be concluded that the contribution of gas flaring in industrial areas is noticeable and application of emission reduction policies at gas flaring, has a major effect on industrial areas and maybe has minor effects on the air quality of the residential areas.

Retrieval of Land Surface Temperature from Earth Observation Satellites for Gas Flaring Sites in the Niger Delta, Nigeria

This research investigates the recording of Land Surface Temperature (LST) by Earth Observation (EO) Satellites for four gas flaring sites in Rivers State, Nigeria. Six Landsat 5 Thematic Mapper (TM) and Eleven Landsat 7 Enhanced Thematic Mapper Plus (ETM+) from 17 January 1986 to 08 March 2013 with < 5% cloud contamination were considered. All the sites are located within a single Landsat scene (Path 188, Row 057). Dark Object Subtraction (DOS) method and Atmospheric Correction Parameter (ATMCORR) Calculator were used to obtain atmospheric correction effects parameters for multispectral and thermal bands [Upwelling radiance (Lu), downwelling radiance (Ld) and transmittance (τ)] of Landsat data respectively. The emissivity (e) for each site is estimated by using standard values for determined land surface cover from Look Up Table (LUT). The correction obtained from DOS method was applied to the computed reflectance to get the atmospherically corrected reflectance that was used for the classification of land cover. The Lu, Ld and τ obtained were applied to the calibrated at-sensor radiance band 6 (high gain) data to compute the surface-leaving radiance (Lλ) with the evalues obtained for each site. The Planck equation was inverted using the calibration constants to derive LST. Six range of LST values were retrieved for each flaring site, with Bonny Liquefied Natural Gas (LNG) Plant recorded the highest LST (345.0 K) and Umudioga Flow Station with the lowest (293.0 K). LST retrieved from both sensors for the flare hotspots are the highest values compared to other locations within the processing sites, which was clearly shown through Geospatial Information System (GIS) spatial analysis and the transects plots. Furthermore, the closer is the distance to the flare, the higher is the temperature and vice versa. Based on these results, it can be concluded that satellite based sensors, such as Landsat TM and ETM+, have the ability to record LST at gas flaring sites in the Niger Delta.

Unburnable and Unleakable Carbon in Western Amazon: Using VIIRS Nightfire Data to Map Gas Flaring and Policy Compliance in the Yasuní Biosphere Reserve

In the Amazon Rainforest, a unique post-carbon plan to mitigate global warming and to protect the exceptional bio-cultural diversity was experimented in 2007–2013 by the Ecuadorian government. To preserve the rainforest ecosystems within the Yasuní-ITT oil block, the release of 410 million metric tons of CO2 would have been avoided. The neologism “yasunization” emerged as an Amazonian narrative on “unburnable carbon” to be replicated worldwide. Considering the unburnable carbon, petroleum-associated gas flaring represents the unleakable part. Flaring is an irrational practice that consists of burning waste gases, representing not only a leak of energy but also a pollution source. The general aim of the paper is to monitor gas flaring as a tool, revealing, at the same time, the implementation of environmental technologies in the oil sector and the compliance of sustainable policies in the Amazon region and the Yasuní Biosphere Reserve. Specific objectives are: (i) identifying and estimating gas flaring over seven years (2012–2018); (ii) mapping new flaring sites; iii) estimating potentially affected areas among ecosystems and local communities. We processed National Oceanic and Atmospheric Administration (NOAA) Nightfire annual dataset, based on the elaboration of imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) and developed a GIS-based novel simple method to identify new flaring sites from daily detections. We found that 23.5% of gas flaring sites and 18.4% of volumes of all oil industries operating in Ecuador are located within the Yasuní Biosphere Reserve (YBR). Moreover, we detected 34 additional flaring sites not included in the NOAA dataset—12 in the YBR and one in Tiputini field, a key area for biological and cultural diversity conservation. We also found that at least 10 indigenous communities, 18 populated centers and 10 schools are located in the potentially affected area. Gas flaring can be used as a policy indicator to monitor the implementation of sustainable development practices in complex territories.

Impact of gas flaring in Ubeji metropolis of Delta State Nigeria: a comparative survey of environment health effects

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The impact of gas flaring in Ubeji metropolis, relative to other communities of Delta is of interest. This study assessed the environmental impact of gas flaring in Ubeji metropolis of Delta State. The objective of this study is to study the comparative assessment of the environmental impacts of gas flaring on five communities of unequal distance from gas flaring site.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Questionnaire survey was used to evaluate three research questions that included the level of knowledge in the survey communities regarding health impact of gas flaring; prevalence level of assessed health conditions in Ubeji metropolis relative to communities farther from or nearer to Warri gas flaring site; and perceived impact of gas flaring on air quality indicated by health and environmental toxicity indices. &lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Descriptive evaluation of data shows Ubeji appears to have the highest proportion of persons suffering respiratory problems, but the figure for family members is less than some other communities. The respondents nearer flaring site show more awareness compared to those farther away. Critical evaluation showed no directional change in prevalence of disease linked to gas flaring. There is linear relationship between ‘distance to gas flare site’ and ‘toxic impact on air quality’.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; This report submits further data to the discourse that, on the basis of nearness to gas flaring site, there is significant difference between communities experience of environmental and health impact.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;

Dynamics of morpho-physiological characteristics of Cassia tora L. (Fabaceae) in oil field pollution stress environment

Flaring of natural gas is an environmental degrading phenomena and effect on texture of the atmosphere. Higher atmospheric carbon dioxide (CO2) changes plant morphological as well as biochemical composition, leading to nitrogen limitation for the plant. Cassia tora, a common weed, was selected to measure the impact of gas flaring in two group gathering stations (GGSs) of Sivasagar district of Assam, India. Epidermal peels as well as scanning electron microscopy observation revealed possible changes in leaf epidermal traits of the plant. CO2 was recorded as the dominant atmospheric gases in nearby areas of gas flaring sites. Apart from this, significant reduction in nitrogen (%), specific leaf area (SLA) (mm2 mg−1), chlorophyll (mg−g) and stomatal pore length (µm) as well as increases in leaf dry matter content (LDMC), leaf thickness (mm) and carbon percentage of C. tora were recorded under CO2 stress environment at both the GGSs. Simulation studies conducted under open-top chamber (OTC) also revealed similar trend.

Assessment of rock slope stability by slope mass rating (SMR): A case study for the gas flare site in Assalouyeh, South of Iran

Slope mass rating (SMR) is commonly used for the geomechanical classification of rock masses in an attempt to evaluate the stability of slopes. SMR is calculated from the RMR89-basic (basic rock mass rating) and from the characteristic features of discontinuities, and may be applied to slope stability analysis as well as to slope support recommendations. This study attempts to utilize the SMR classification system for slope stability analysis and to investigate the engineering geological conditions of the slopes and the slope stability analysis of the Gas Flare site in phases 6, 7 and 8 of the South Pars Gas Complex in Assalouyeh, south of Iran. After studying a total of twelve slopes, the results of the SMR classification system indicated that three slope failure modes, namely, wedge, plane and mass failure were possible along the slopes. In addition, the stability analyses conducted by a number of computer programs indicated that three of the slopes were stable, three of the slopes were unstable and the remaining six slopes were categorized as \'needs attention\' classes.

Assessment of discontinuous rock slope stability with block theory and numerical modeling: a case study for the South Pars Gas Complex, Assalouyeh, Iran

In this study, a geotechnical model has been used to analyze the stability of a discontinuous rock slope. The main idea behind block theory is that it disregards many different combinations of discontinuities and directly identifies and considers critical rock blocks known as “key blocks”. The rock slope used as a case study herein is situated in the sixth phase of the gas flare site of the South Pars Gas Complex, Assalouyeh, Iran. In order to analyze the stability of discontinuous rock slopes, geotechnical modeling which was divided into geometrical sub-modeling and mechanical sub-modeling has been utilized. This model has been established upon the KGM (key-group method) algorithm which was based on the limit equilibrium method and block theory and prepared and coded by the Mathematica software. According to the results of the stability analysis, the analyzed slope was determined to be in the category of “needs attention,” and the security level, calculated through the FORM (first-order reliability method) analysis, was estimated to be 1.16. In order to verify the model, the results obtained from the model were compared with those of the UDEC software, which is a numerical method based on distinct components. As a conclusion, it was determined that the results of the model agreed well with those of the numerical method.

Leaf epidermal changes in three common crop plants found in a gas-flared community in Oben Village, Edo State Nigeria

The study investigated the impact of gas flaring on soil and air quality, as well as quantitative and qualitative anatomical characters of three selected plants Musa paradisiaca , Carica papaya and Talinum triangulare in and around Oben Flow Station. Most of these test crop plants located around the gas flare site showed signs of chlorosis, wilting and stunted growth. The interrelationship between the morphological characters of polluted and non-polluted plants was compared. The epidermal cell shape identified on adaxial and abaxial side of all the study plants varied from polygonal, elongated to wavy/sinous cell shape. Anticlinal wall varied from curved, undulated to straight in all test plants. Stomata number was more on the abaxial surface than adaxial surface in all the plants. In this study hypo-stomatic and amphi-stomatic were identified, among the species where anomocytic stomata is found in abaxial layers of all the three species Hemiparacytic in adaxial of T. triangulare and Anomocytic with cell inclusion distributed all around the cell layers of the Plants. The leaves of non-polluted plants grew normally while the polluted plants suffered anatomical aberration; Cell disruption in leaves was eminent. Keywords: Flaring, pollution, plant anatomy, Musa paradisiaca , Carica papaya and Talinum triangulare

Numerical modeling of discontinuous rock slopes utilizing the 3DDGM (three-dimensional discontinuity geometrical modeling) method

The geometry of discontinuities in a rock mass is one of the most important influences on the behavior and characteristics of that rock mass. The geometry of discontinuities largely determines the stability of the rock mass, as well as appropriate methods for reinforcing and stabilizing that mass. This study introduces the 3DDGM (three-dimensional discontinuity geometrical modeling) method, which is based on the 3DGM (three-dimensional geometrical modeling) algorithm that was developed using the Mathematica software package. The 3DDGM method provides essential input data for the stability analysis of a discontinuous rock mass using block stability assessment techniques or block modeling codes. The 3DDGM method developed in the present work was designed to model discontinuities in rock masses and to provide accurate values for discontinuity parameters (i.e., location, spacing, separation, system, orientation, etc.). This algorithm was developed to increase the accuracy of the discontinuity model based on the Heliot algorithm. The 3DDGM algorithm was tested by applying it to a real case, the sloping discontinuous rock mass at the phase 7 gas flare site in the South Pars Gas Complex in Assalouyeh, Iran, and the algorithm was successful in providing a three-dimensional model of the discontinuities in the rock mass at the site.

Impact of Crude Oil Storage Tank Emissions and Gas Flaring on Air/Rainwater Quality and Weather Conditions in Bonny Industrial Island, Nigeria

This study investigated the effects of gaseous emissions from crude storage tank and gas flaring on air and rainwater quality in Bonny Industrial Island. Ambient air quality parameters, rainwater and weather parameters were collected at 60 m, 80 m, 100 m, 200 m and control plot for 4 weeks at the Bonny. Rainwater parameters were investigated using standard laboratory tests. Data analyses were done using Analysis of variance, pairwise t-test and Pearson’s correlation statistical tools. Results show that emission rates, volatile organic compound (VOC) noise and flare temperature decreased with increasing distance from flare points and crude oil storage tanks. Findings further revealed the emission rates varied significantly with distance away from the gas flaring point (F = 6.196; p = 0.004). The mean concentration of pollutants between gas flare site and crude oil storage tank showed that CO (0.02 ± 0.001 - 0.002 ±0.001), SPM (0.011 ± 0.001 - 0.01 ± 0.001), VOC (0.005 ± 0.001 - 0.01 ± 0.001) and NO2 (0.04 ± 0.001 - 0.005 ± 0.000) had significant variations (p > 0.05) with CO, O3 and NO2 having higher concentrations at the gas flare site while SPM, and VOC were higher around the crude oil storage tank site. Wind turbulence was higher around the gas flaring point (4.93 TKE) than the crude oil storage tank (4.55 TKE). Similarly, there was significant variation in the sun radiation, precipitation, and wind speed caused by gas flaring (1582.25 w/m2, 436.25 mm, 0.53 m/s) and crude oil storage tank (1536.25 w/m2, 3.91.41 mm, 0.51 m/s). There were also significant variations in flared temperature (F = 22.144; p = 0.001); NO2 (F = 8.250; p = 0.001), CO (F = 6.000; p = 0.004) and VOC (F = 5.574; p = 0.006) with distance from the gas flaring point. The variation in the rainwater parameters with distance from the gas flaring indicated significant variations in pH (F = 5.594; p = 0.006). The study showed that the concentration of VOC and particulates were high in the supposedly control area which is perceived to be safe for human habitation. Significant variations exist in emission rate (p = 0.015), flare temperature (p = 0.001), NO2 (p = 0.003), VOC (p = 0.001), noise (p = 0.041), hydrogen carbonate (p = 0.037) and chromium (p = 0.032) between the gas flaring and crude oil storage tank. Regular monitoring is advocated to mitigate the harmful effects of the pollutants.

Effect of Gas Flaring on Soil and Cassava Productivity in Ebedei, Ukwuani Local Government Area, Delta State, Nigeria

The threat to human, fauna and flora life posed by pollution due to gas flaring cannot be over-emphasized. Gas flared often resulted in some environmental degradation, one of such influence is soil pollution and poor crop yield. This study examined the effect of gas flaring on soil and cassava productivity in Ebedei, Ukwuani LGA, Delta State. For the purpose of data collection, five (5) experimental sites were systematically selected around the flare site in Ebedei and a control site at Obiaruku. Soil samples were collected at surface 0 - 10 cm and 10 - 20 cm at distance of 50 m, 100 m, 150 m, 200 m and 250 m apart respectively away from the bund wall of the flare. The data generated were analysed using multiple regression and paired t-test analyses. The study revealed that the soils found in Ebedei have high composition of sand and soil temperature and are acidic. The soil electrical conductivity, Phosphorous, Nitrogen, Potassium and Sodium were very low. More so, the yield of cassava increases with a corresponding increase in distances from flare site. The first hypothesis revealed that there is significant variation in soil nutrients as distance increases from gas flare sites. This is evident from F value of 234.99 which is greater than the critical table value of 4.39. Furthermore, as flare distance increases, so also the organic carbon, electrical conductivity and Nitrogen increase. The second hypothesis revealed that there is a significant difference in cassava yield at gas-flared area and the non-flared area which is evident at t (6.032) is greater than the critical table (1.895) at P 0.05. It is therefore recommended that Government and FEPA should enact environmental Policies and revisit and review existing environmental and oil drilling laws in Nigeria with a view of updating them to international and environmental friendly standards.

Investigation of the Effects of Using Gas Flare to Dry Tapioca (Kpokpo-Garri) at Gana Flow-Station in Agbarha,Delta State, Nigeria

Local women in the Niger Delta use oil companies' gas flare sites to dry a popular cassava base food, kpokpo-garri (tapioca).This work is on the investigation of the effects of using gas flare to dry tapioca in the Niger Delta region of Nigeria. Two samples of tapioca dried with gas flare at Gana flow station, Agbarha were analyzed using a Unican 929 atomic absorption spectrophotometer for the presence of hazardous heavy metals. Fe, Mn, Pb, Cd, Ni and Zn were found in the dried tapioca in quantities above WHO safe limits. These make the dried tapioca unsafe for consumption. There is therefore the need for alternative means such as sun or oven to dry tapioca.

Economic Evaluation of Crop Farms Acquired for Crude Oil Production Activities in Rivers State of Nigeria

This study focused on the economic evaluation of crop farms acquired forcrude oil production activities in Rivers State, Nigeria. The objectivesinclude estimating the areas of crop farms acquired and economic evaluation of crops lost due to the various crude oil production activities in the state. A multistage sampling technique was used to collect data from 169 crop farmers whose farmland were affected with different crude oil exploration activities via questionnaires. The results showed that a total of 682.91ha of crop farms were acquired for crude oil exploration purposes out of which pipelines laying (25.21%), flow stations (21.51%) and oil well sites (20.34%) topped the list. The results further showed that the total value of economic loss due to crude oil production activities was $165,287.10 out of which pipelines laying accounted for $43,741.25, flow stations ($36,387.92), oil well sites ($31,334.67), gas flaring sites ($10,485.63). The study showed that large areas of crop farms in the state were acquired for crude oil production activities. Due to the small scale nature of farms in Nigeria, a lot of crop farmers in Rivers State were negatively affected which had resulted into agitation for resource control, continuous violence, conflicts, protests and impoverishment. Keywords: Crude oil production activities, crop farms, areas acquired,economic evaluation, Rivers State Nigeria.

Spatial variation in acid and some heavy metal composition of rainwater harvesting in the oil-producing region of Nigeria

The study adopted the experimental research design and field survey of the oil-producing region of Nigeria for the past 10 years. A total of 100 sterilized rain gauges were randomly distributed on the basis of 50 each to the eastern and western division of the oil company operating in the region. The rainwater samples harvested through this process were transferred into sterilized plastic containers and kept in coolers and taken immediately to the laboratory for analysis soon after every rain event. The rainwater samples were analysed in the laboratory with the most appropriate techniques. The physicochemical characteristics of rainwater harvested were subjected to paired t test and 3-year moving average statistical analysis. The following are the results: There is widespread acid rain in the region, this is evident from pH values that span 4.98–5.15 and 5.06 mean values. The result also revealed that acid rain (pH) varied significantly (P > 0.05), and it decreases with increasing distance from gas flare sites throughout the period of study. Other physicochemical characteristics of rainwater resources conform to safe limit with the exception of turbidity, TSS, Pb and NO3, which is also significant at P > 0.05 with increasing distance from the gas flare sites, as such they decreases with increasing distance. This certainly has serious environmental effects on the human and other species, soil, water and vegetation resources and calls for the extinction of gas flaring, in this region. Sources of water that are acidified should be periodically limed to reduce the acid concentration in such water.

Socio-demographic factors of adult malignant lymphomas in Benin City, Nigeria

The aim of this study is to determine the incidence and sociodemographic factors associated with adult malignant lymphoma in Benin City, Niger Delta region of Nigeria. A retrospective study of 205 patients with a diagnosis of lymphoma seen over a 13-year period (1990-2003) at the University of Benin Teaching Hospital, Nigeria. They were analyzed in the context of gender, marital status, geographical abode, educational and occupational status. The patients had sufficient data recorded at diagnosis to allow retrospective assignment into the various subtypes. There were 70 males and 135 females with a male-to-female ratio of 1:1:9. Non-Hodgkin's lymphoma (NHL) was more frequent (83%) while Hodgkin's lymphoma had incidence of 17%. Marital status (P = 0.0002), geographical abode (p = 0.0046), educational (P = 0.0045) and occupational status (p = 0.0001) were significantly associated with the malignant lymphoma at presentation. All the lymphoma subtypes were most common in patients who resided in Delta state, a major oil producer. The majority of the lymphoma patients (46.3%) had tertiary form of education. The highest and lowest social classes were most likely to have lymphoma, which may have been related to age and industrial exposure. Poverty and illiteracy are additional problems with patients with malignant lymphomas. Living in Delta State where the petrochemical industries and gas flare sites are located may be a risk factor for the development of lymphoma.

Adult lymphomas in Edo state, Niger Delta region of Nigeria - clinicopathological profile of 205 cases

The clinicopathologic features of malignant lymphomas had not been documented in the Niger Delta region of Nigeria, which is known for its petrochemical industries and gas flare sites. Cases of lymphomas that presented to the University of Benin Teaching Hospital (UBTH), a major referral centre in the region, from January 1990 to December 2003 were reviewed. Demographic and clinical information were obtained from the case files. Diagnosis was established based on the histological examination of an accessible biopsy lymph node and classified according to the Working Formulation (WF). Haematological parameters were done using an automated Coulter counter. Non-Hodgkin's lymphoma (NHL) occurred predominantly in young adults (20-39 years). A majority of the patients presented in the advanced stage of the disease (Stages III-IV) according to the Ann Arbor system and a performance status (PS) scale of 2-4. The intermediate grade NHL (41.2%) formed the largest group of which diffuse large cell lymphoma (DLCL) was the most commonly observed histopathologic type followed by the large cell immunoblastic type.

Thermal tolerance of the West African fiddler crab (&lt;i&gt;Uca tangeri&lt;/i&gt;) to heated effluents from gas flare sites

Experiments were conducted both at the heated effluents discharge point of a gas flare station in the Niger Delta region and in the laboratory to determine the thermal tolerance of the West African fiddler crab (Uca tangeri). The critical thermal maxima (CTM) was 38oC. Time required for 100% recovery vary from 3 minutes - 50 minutes at temperature ranging 33oC - 37oC after 30 mins exposure. Mortality were observed from 38oC. Elevated temperature could therefore be a lethal factor which determines the distribution of Uca tangeri around heated effluents discharge point of a gas flare station. Keywords: Thermal tolerance Uca tangeri Niger Delta [Global Jnl Environ Sci Vol.2(1) 2003: 41-45]