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Natural gas flaring, with its harmful environmental, health, and economic effects, is common in the Nigerian oil and gas industry because of a lower tax regime for flared gases. Based on the adverse effects of flared gas, the Nigerian government has renewed and improved its efforts to reduce or eliminate gas flaring through the application of natural gas utilisation techniques. However, because the conventional approach to flare gas utilisation is heavily reliant on achieving scale, fuel, and end-product prices, not all technologies are technically and economically viable for typically capturing large and small quantities of associated gas from various flare sites or gas fields (located offshore or onshore). For these reasons, this paper reviews and compares various flare gas utilisation options to guide their proper selection for appropriate implementation in the eradication of routine gas flaring in Nigeria and to promote the Zero Routine Flaring initiative, which aims to reduce flaring levels dramatically by 2030. A qualitative assessment is used in this study to contrast the various flare gas utilisation options against key decision drivers. In this analysis, three natural gas utilisation processes—liquefied natural gas (LNG), gas to wire (GTW), and gas to methanol (GTM)—are recommended as options for Nigeria because of their economic significance, technological viability (both onshore and offshore), and environmental benefits. All these gas utilisation options have the potential to significantly reduce and prevent routine gas flaring in Nigeria and can be used separately or in combination to create synergies that could lower project costs and product market risk. This article clearly identifies the environmental benefits and the technical and economic viability of infrastructure investments to recover and repurpose flare gasses along with recommendation steps to select and optimise economies of scale for an associated natural gas utilisation option. [ABSTRACT FROM AUTHOR]

In 2019, Nigeria contributed 7, 825 million cubic meters (mln m3/yr) to global greenhouse gas emissions. A legal framework has been developed to curb gas flaring and create the incentive to utilise flare gas, which is derived in part from existing legislation, and from market-based incentives. This developed a mechanism to convert waste gas into wealth while protecting health and the environment - a winning formula. Given that the objective of the framework is to guard against waste and protect the environment, it has wasted an opportunity to convert flare emissions into wealth by creating a framework for the deployment of carbon technologies to guard against the environmental impact of gas flaring. This is pertinent because as the industry transits to low carbon, and as oil exploration is expected to continue in the immediate future, critical stakeholders are now investing in carbon technologies. The legal framework mostly channels its technologydriven approach towards utilising flare gas. However, this article finds that the mechanism for converting flare gas to wealth in the legal framework presents an opportunity to harness the potential carbon technologies to develop mechanisms for capturing and utilising carbon from flare facilities, building other industry ecosystems, and developing other environmentally sustainable value chains. As Nigeria continues to explore its petroleum resources, a framework to encourage its deployment is missing. This article analysis carbon technologies highlighting how they are deployed to tackle emissions and utilise emitted carbon. It also reviews the legal framework for curbing gas flaring in Nigeria and proposes by way of recommendation a legal framework for the deployment of carbon technologies to curb the environmental impact of gas flaring in Nigeria that paves the way for incentivising and developing other environmentally sustainable industrial ecosystems that utilise captured emissions from flare sites. [ABSTRACT FROM AUTHOR]

• Health risk assessment of BTEX emitted from gas flares of five refineries was studied in refineries sites, two cities and two camps nearby refineries. • AERMOD model coupled with WRF model have been applied for predicting concentrations of BTEX emitted from gas flares. • The relative contribution of Benzene is higher than other BTEX compounds emitted from gas flares in both noncancer and cancer risk assesment. • The contribution of BTEX emitted from gas flares in total risk of BTEX is more significant inside refineries sites than residential areas. 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 SO 2 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. [ABSTRACT FROM AUTHOR]

Gas flaring is one of the key processes used in major oil-producing countries to dispose of associated gas at oil production sites, processing plants, or refineries. It is a controversial process, which has raised global concerns, thus, generating research interests globally. Difficulties encountered in accessing official information on gas flaring prompted the development of alternative techniques for deriving vital flaring information from space. This review paper discussed the underlying principles of remote sensing of gas flares. In addition, historical developments in satellite flaring studies with various satellite imageries (AVHRR, DMSP-OLS, ATSR, Landsat, MODIS, Soumi-VIIRS and Sentinel-3 SLSTR) and recent advances were discussed. Advantages and limitations of the various techniques, as well as future directions and applications, were discussed to stimulate further research into this relatively nascent area of study. [ABSTRACT FROM AUTHOR]

The article details the case of Gbemre v. Shell Petroleum-Nigeria, in which the Nigerian Federal High Court concluded that illegal flaring of natural gas contravenes a right to dignity guaranteed by the Constitution of Nigeria. Topics discussed include adverse effects of flaring on human health and the environment, role that human dignity plays in vindicating constitutional rights around the globe, and in Nigeria in particular, and background on the Gbemre lawsuit.

Abstract An understanding of the dispersion and level of emissions source of atmospheric pollutants; whether point, area or volume sources, is required to inform policies on air pollution and day-to-day predictions of pollution level. Very few studies have carried out simulations of the dispersion pattern and ground-level concentration of pollutants emitted from real-world gas flares. The limited availability of official data on gas flares from the oil and gas industries makes accurate dispersion calculations difficult. Using ADMS 5 and AERMOD, this study assessed the sensitivity of dispersion and ground-level concentration of pollutants from gas flares in the Niger Delta to prevailing meteorological condition; fuel composition; and flare size. Although, during the non-WAM (West African Monsoon) months (November and March), the simulated ground-level concentrations of pollutants from a single flare are lower, the dispersion of pollutants is towards both the inland and coastal communities. In the WAM months, the ground-level concentrations are higher and are dispersed predominantly over the inland communities. Less buoyant plumes from smaller flares (lower volume flow rates) and/or flaring of fuel with lower heat content results in higher ground-level concentrations in areas closer to the flare. Considering the huge number of flares scattered around the region, a mitigation of the acute local pollution level would be to combine short stacks flaring at lower volume flow rates to enhance the volume flow rate of a single exhaust, and hence, the buoyancy of the plume exiting the stack. Graphical abstract Image 1 Highlights • During monsoonal flow ambient ground-level concentrations are higher and inland. • There is higher individual exposure during the WAM (West African Monsoon) months. • There is greater population dose during the non-WAM months. • Flare and fuel characteristics play major roles in emissions yields from flares. • Both ADMS and AERMOD are adequate for simulating emissions from gas flares. [ABSTRACT FROM AUTHOR]

Abstract—: This paper compares features of the generation of coronal mass ejections (CMEs) with the lowest, intermediate, and highest velocities in the field of view of LASCO C2 and C3 coronagraphs found from an analysis of multi-wavelength data with high temporal and spatial resolution. The dynamics of the field characteristics in the umbra of sunspots of active regions (ARs) in which variable-velocity CMEs occur are compared based on SDO/HMI vector magnetic field measurements. It is found that there are almost no noticeable changes in field characteristics in the AR sunspots in which slow CMEs occur after the onset of the eruptive event. However, there are noticeable changes in the field intensity and inclination angles of the flux tube emerging from the umbra of the sunspot in some AR sunspots in which CMEs occur after the onset of the eruptive event. Thus, for the fast CME detected on January 7, 2014, the inclination angle of the flux tube from the umbra of one of the sunspots before the flare onset reached a maximum value of ≈4°. After the flare onset, it was less than 1°. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) as methane adsorbents are highly promising materials for applications such as methane‐powered vehicles, flare gas capture, and field natural gas separation. Pre‐ and post‐synthetic modification of MOFs have been known to help improve both the overall methane uptake as well as the working capacity. Here, a post‐synthetic modification strategy to non‐covalently modify MOF adsorbents for the enhancement of the natural gas uptake for the MOF material is introduced. In this study, PCN‐250 adsorbents were doped with C10 alkane and C14 fatty acid and their impact on the methane uptake capabilities was investigated. It was found that even trace amounts of heavy hydrocarbons could considerably enhance the raw methane uptake of the MOF while still being regenerable. The doped hydrocarbons are presumably located at the mesoporous defects of PCN‐250, thus optimizing the framework–methane interactions. These findings reveal a general approach that can be used to modify the MOF absorbents, improving their ability to be sustainable and renewable natural gas adsorption platforms. A non‐covalently modified mesoporous metal–organic framework (MOF) with long‐chain hydrocarbons could significantly increase the already high methane uptake. The long‐chain fatty acid was assumed to be coordinated to the open metal site and located at the mesoporous defects of the MOF. Through optimized partitioning of the mesoporous space of MOF by the doped hydrocarbons, more methane was packed into the pores of the MOF through hydrophobic interactions. [ABSTRACT FROM AUTHOR]

Abstract—: A combination of the syngas generation and methanol synthesis steps by pressure is considered to obtain methanol from oil- and gas-fields flare gases. The combined process is thermodynamically analyzed within 700-1100°C and 2-10 MPa for flare gas conversion into syngas. The features of the synthesis of syngas by steam, steam-oxygen, and steam-air conversion are considered. The combined steam conversion of flare gas at 900-950°C and the synthesis of methanol at 230°C together with a total pressure of 3.5-5 MPa make it possible to produce methanol with a yield of up to 1.1 tmethanol/traw and may be recommended for the qualified processing of flare gas into methanol directly on the fields. The synthesis of methanol from syngas with a high amount of CO2 is experimentally verified on copper-zinc catalysts at 230-270°C and 5-8 MPa. [ABSTRACT FROM AUTHOR]

This study describes the results of a “well-to-wheel” life cycle assessment (LCA) carried out to determine the potential greenhouse gas and criteria pollutant emission reductions that could be achieved by converting associated flare gas directly to synthetic fuels at oil wellheads in the US and globally. A Greyrock Flare Gas-to-Fuels™ conversion process at an Ohio oil well was used as the base case for this LCA. The liquid fuel produced directly from associated gas is comprised primarily of premium synthetic diesel with a small amount of synthetic gasoline. In this LCA scenario, the synthetic diesel and synthetic gasoline are blended at 20 and 10 vol% with petroleum diesel and gasoline, respectively. While the synthetic diesel fuel can be used as is (100%), the 20 vol% synthetic diesel blend (with petroleum diesel) was found to significantly improve engine performance, increase fuel economy, and reduce emissions. The direct conversion of associated gas to synthetic diesel fuels globally could reduce emissions of CO2 and CH4 by up to 356 and 5.96 million metric tons/year, respectively, resulting in the reduction of greenhouse gases (GHGs) by about 113.3 and 92.2% (20 year global warming potential) and 73.8 and 50.7% (100 year global warming potential) for synthetic diesel and gasoline fuels when compared to petroleum-derived gasoline fuels, respectively. Likewise, diesel criteria emissions could be reduced globally by up to 23.3, 0.374, 42.4, and 61.3 million metric tons/year globally for CO, particulates, NOx, and hydrocarbons, respectively. The potential economic benefit of this approach is that up to 5.30 and 71.1 billion liters of synthetic fuels could be produced each year in the US and globally from associated gas, respectively. [ABSTRACT FROM AUTHOR]

In the present study, application of catalytic membrane reactor as a novel approach for the flare gas recovery is proposed. A comprehensive two-dimensional non-isothermal model has been constructed to evaluate the performance of flare gas recovery process in the membrane reactor. The model is developed by taking into accounts the main chemical kinetics, heat and mass transfer phenomena and hydrogen permeation in the radial direction across a Pd–Ag membrane. The model predictions are validated based on different experimental results reported in literature. The impact of reactor operating conditions on the recovery process such as temperature and pressure, feed molar ratio and sweep gas ratio are investigated and discussed. The modeling results confirm that the flare gas conversion and hydrogen recovery improves with increasing the operating temperature, pressure and sweep ratio as a consequence of increasing the driving force for H 2 permeation through membrane. The environmental consideration revealed that by application of catalytic membrane reactor for the flare gas recovery of Asalouyeh gas processing plant (Iran), not only the equivalent mass of greenhouse gases emission reduces from 2179 kg/s to 36 kg/s, but also, 12.7 kg/s pure hydrogen will be produced by flare gas recovery at 750 K, 5 bar, sweep ratio of 5 and feed molar ratio of 4. [ABSTRACT FROM AUTHOR]

Flare gas recovery (FGR) is known as an option to reduce greenhouse gases (GHG) from oil and gas refineries. The major concerns about environmental impacts of GHG emission lead refineries to deploy different FGR methods, most of which requiring new equipment and high cost of design and construction. In this paper, feasibility of three methods for FGR is evaluated in a giant gas refinery in Iran. The first two methods considered liquefaction and LPG production by implementing flare gases as feed for existing LPG unit. Different parameters were studied in feed liquefaction and LPG production. The third studied option is using a three-stage compression unit to compress the flare gases. Finally, an economic evaluation was performed to find the most profitable method. Based on simulation results, the 0.75-barg pressure of flash drum leads to maximum LPG production. For FGR, the 1-barg pressure of flash drum recovered the most CO 2 -equivalent from releasing into the atmosphere, which is more than 205 ton/day. The economic evaluation shows that rate of return (ROR) for liquefaction unit and LPG production unit are more than 200% for different scenarios and are higher than compression. [ABSTRACT FROM AUTHOR]

The radiative power (MW) output of a gas flare is a useful metric from which the rate of methane combustion and carbon dioxide emission can be inferred for inventorying purposes and regular global surveys based on such assessments are now being used to keep track of global gas flare reduction efforts. Several multispectral remote sensing techniques to estimate gas flare radiative power output have been developed for use in such surveys and single band approaches similar to those long used for the estimation of landscape fire radiative power output (FRP) can also be applied. The MIR-Radiance method, now used for FRP retrieval within the MODIS active fire products, is one such single band approach--but its applicability to gas flare targets (which are significantly hotter than vegetation fires) has not yet been assessed. Here we show that the MIR-Radiance approach is in fact not immediately suitable for retrieval of gas flare FRP due to their higher combustion temperatures but that switching to use data from a SWIR (rather than MWIR) spectral channel once again enables the method to deliver unbiased FRP retrievals. Over an assumed flaring temperature range of 1600-2200 K we find a maximum FRP error of ±13.6% when using SWIR observations at 1.6 µm and ±6.3% when using observations made at 2.2 µm. Comparing these retrievals to those made by the multispectral VIIRS 'NightFire' algorithm (based on Planck Function fits to the multispectral signals) we find excellent agreement (bias = 0.5 MW, scatter = 1.6 MW). An important implication of the availability of this new SWIR radiance method for gas flare analysis is the potential to apply it to long time-series from older and/or more spectrally limited instruments, unsuited to the use of multispectral algorithms. This includes the ATSR series of sensors operating between 1991-2012 on the ERS-1, ERS-2 and ENVISAT satellites and such long-term data can be used with the SWIR-Radiance method to identify key trends in global gas flaring that have occurred over the last few decades. [ABSTRACT FROM AUTHOR]

The civilisation is in the continuous search for energy resources, either already in use or new ones, for future needs. The gas hydrates are one of the unconventional resources that have been identified, evaluated and in the future will be probably exploited. The semi-enclosed Black Sea Basin has an excellent potential for free gas and gas hydrate accumulation, on account of its anoxic water regime which favours the preservation of organic matter in the sediments (the chemocline lies at 110-140 m depth). Regions outside the stability field of gas hydrates, namely, the shelf and upper slope, show a high gas content in the sediments. The Black Sea Basin has been the focus for numerous research projects, which led to the identification of the BSR that might be associated with the gas hydrate zones. Beside the gas hydrates, numerous gas occurrences have been recognized on the seafloor of the Black Sea in different sectors and at different depths, including shelf and slope of Romanian Black Sea area, and a significant amount of data have been published. The current synthesis aims to make a review of the results published in the last 15 years describing geological structure and evolution of the Black Sea Basin, as well as bottom sediments, gas hydrates, flare and escape structures Offshore Romania. [ABSTRACT FROM AUTHOR]

In this work, a distillation system is designed to purify dimethyl ether (DME) from its reaction by-products in the conversion of flare gas into a useful energy product. The distillation equipment has a size constraint for easy transportation, making process intensification the best strategy to efficiently separate the mixture. The process intensification distillation techniques explored include the dividing wall column (DWC) and a novel semicontinuous dividing wall column (S-DWC). The DWC and the S-DWC both purify DME to fuel grade purity along with producing high purity waste streams. An economic comparison is made between the two systems. The DWC is a cheaper method of producing DME however the purity of methanol, a reaction intermediate, is not as high as the S-DWC. Overall, this research shows that it is possible to purify DME and its reaction by-products in a 40-foot distillation column at a cost that is competitive with Diesel. [ABSTRACT FROM AUTHOR]

Flare emissions, especially start-up flare emissions, during chemical plant operations generate large amounts of ozone precursors that may cause highly localized and transient ground-level ozone increment. Such an adverse ozone impact could be aggravated by the synergies of multiple plant start-ups in an industrial zone. In this paper, a systematic study on ozone increment superposition due to chemical plant start-up emissions has been performed. It employs dynamic flaring profiles of two olefin plants’ start-ups to investigate the superposition of the regional 1-hr ozone increment. It also summaries the superposition trend by manipulating the starting time (00:00–10:00) of plant start-up operations and the plant distance (4–32 km). The study indicates that the ozone increment induced by simultaneous start-up emissions from multiple chemical plants generally does not follow the linear superposition of the ozone increment induced by individual plant start-ups. Meanwhile, the trend of such nonlinear superposition related to the temporal (starting time and operating hours of plant start-ups) and spatial (plant distance) factors is also disclosed. This paper couples dynamic simulations of chemical plant start-up operations with air-quality modeling and statistical methods to examine the regional ozone impact. It could be helpful for technical decision support for cost-effective air-quality and industrial flare emission controls. [ABSTRACT FROM AUTHOR]

Current flare and jet fire models used in the process industry are primarily based on hydrocarbon gases and have been found not to be particularly effective for low luminosity gases such as hydrogen and syngas mixtures. This article presents a new model for such gases, for low to high pressure releases in both vertical and horizontal orientations. The model, which predicts flame geometry and thermal radiation, allowing for jet momentum, buoyancy, wind and flame radiant fraction, is based on extension of established models, with the addition of several new correlations. Validation against existing published data and new previously unpublished test data collected at both pilot and full scale is presented. This article provides the complete set of equations for the model. © 2016 American Institute of Chemical Engineers Process Saf Prog 36: 237-251, 2017 [ABSTRACT FROM AUTHOR]

An optimization approach is proposed for managing flares from multiple plants. The aim of the proposed approach is to utilize flared gas during an abnormal situation to produce combined heat and power while reducing the environmental impact associated with emitting greenhouse gases (GHGs) into the atmosphere. A mixed-integer nonlinear programming model is proposed to determine the optimal size of equipment for the cogeneration system. The model takes into account the uncertainty associated with the price volatility of external fuels and the characteristics of flare streams including the Wobbe Index. Starting from historical data, several scenarios are randomly generated to emulate variations in the uncertain variables with several levels of risk. A case study is presented to show the applicability of the proposed system. The results show economic and environmental benefits emanating from reductions in operating cost and GHGs emissions. [ABSTRACT FROM AUTHOR]

Gas flaring is commonly used by industrial plants for processing oil and natural gases in the atmosphere, and hence is an important anthropogenic source for various pollutants including CO2, CO, and aerosols. This study evaluates the feasibility of using satellite data to characterize gas flaring from space by focusing on the Khanty-Mansiysk Autonomous Okrug in Russia, a region that is well known for its dominant gas flaring activities. Multiple satellite-based thermal anomaly data products at night are intercompared and analyzed, including MODIS (Moderate Resolution Imaging Spectroradiometer) Terra level 2 Thermal Anomalies product (MOD14), MODIS Aqua level 2 Thermal Anomalies product (MYD14), VIIRS (Visible Infrared Imaging Radiometer Suite) Active Fires Applications Related Product (VAFP), and VIIRS level 2 Nightfire product (VNF). The analysis compares and contrasts the efficacy of these sensor products in detecting small, hot sources like flares on the ground in extremely cold environments such as Russia. We found that the VNF algorithm recently launched by the National Oceanic and Atmospheric Administration (NOAA) has the unprecedented accuracy and efficiency in characterizing gas flares in the region owing primarily to the use of Shortwave Infrared (SWIR) bands. Reconciliation of VNF’s differences and similarities with other nighttime fire products is also conducted, indicating that MOD14/MYD14 and VAFP data are only effective in detecting those gas flaring pixels that are among the hottest in the region; incorporation of shortwave infrared (1.6 μm) band used in VNF may improve the detection of relatively cooler gas flares. The gas flaring locations from the VNF product are validated using Google Earth images. It is shown that VNF’s estimates of the area of gas flaring agree well with the Google image counterparts with a linear correlation of 0.91, highlighting its potential use for routinely monitoring emissions of gas flaring from space. [ABSTRACT FROM AUTHOR]

Today in the worldwide quest for production and economic preference, only industries will survive that have proper solutions for waste disposal and environmental pollution. In industrial applications, a blow down network of gases is used in order to control system pressure and safety instruments. At the end of this network, the excess gases are burnt in the flare tower, which have severe consequences on the environment. Different methods have been proposed and several alternatives have been introduced for reduction and recovery of flaring gases. In this paper, three methods including gas to liquid (GTL), gas turbines generation (GTG) and gas to ethylene (GTE) are introduced and compared with the best method from economic point of view being identified. For this purpose, a natural gas sample is taken from Asalloyeh Refinery Plant and the process has been simulated using Aspen HYSYS. Meanwhile, estimation of the capital and operating costs and evaluation of the processes involved were made using Aspen Capital Cost Estimator. According to the results obtained, production of the electric power from flaring gases is one of the most economical methods. GTG method, with an annual profit of about 480e+006 $, has a greater ROR percent. [ABSTRACT FROM AUTHOR]

The world today recognizes the significance of environmental sustainability to the development of nations. Hence, the role oil and gas industry plays in environmental degrading activities such as gas flaring is of global concern. This study presents material balance equations and predicts results for non-hydrocarbon emissions such as CO 2 , CO, NO, NO 2 , and SO 2 etc. from flaring (combustion) of 12 natural gas samples representing composition of natural gas of global origin. Gaseous emission estimates and pattern were modelled by coding material balance equations for six reaction types and combustion conditions with a computer program. On the average, anticipated gaseous emissions from flaring natural gas with an average annual global flaring rate 126 bcm per year (between 2000 and 2011) in million metric tonnes (mmt) are 560 mmt, 48 mmt, 91 mmt, 93 mmt and 50 mmt for CO 2 , CO, NO, NO 2 and SO 2 respectively. This model predicted gaseous emissions based on the possible individual combustion types and conditions anticipated in gas flaring operation. It will assist in the effort by environmental agencies and all concerned to track and measure the extent of environmental pollution caused by gas flaring operations in the oil and gas industry. [ABSTRACT FROM AUTHOR]

Upset emissions occur during plant startup, shutdown, maintenance, malfunction, and flaring incidents. A wide range of these upsets cannot be managed by standalone control systems; plant personnel intervention is necessary sometimes. The methods needed to assist plant personnel to control and prevent abnormal process operations are gathered under abnormal situation management. Abnormal operations that lead to flare have significant economic, environmental, and safety impacts. Flaring is necessary for managing process upsets, however, it leads to the emission of greenhouse gases (GHG) and volatile organic compounds (VOCs), causing negative social impacts and local transient air pollution. In addition, excessive flaring results in energy and raw material losses. These are valuable commodities that must be sustained. Therefore, flare minimization during normal and abnormal operational situations has great environmental, industrial, and societal benefits. It is not possible to quantify the impacts without understanding the properties and magnitude of these upsets. Such analysis requires extensive amount of historical data. There are large sets of design, operational, and flaring data readily available; however, the challenge when it comes to flare mitigation is in using them effectively and in a timely manner. In this Article, a systematic approach to collect, analyze and utilize historical flaring data based on current industrial practices is presented. An ethylene base case study along with its historical process and flaring incidents data is used to demonstrate the significance of using and integrating data within developed flare management strategies. In the presented case, design and historical process data are used to assess the environmental impacts of abnormal incidents and to identify underlying causes and indicators that lead to process upset, that is, abnormal situations. The data sets are utilized within an optimization algorithm to identify design alternatives to mitigate process incidents and reduce its root causes. The paper highlights the challenges that are faced by environmental agencies in terms of data utilization and documentation. [ABSTRACT FROM AUTHOR]

Recent emphasis on Recognized and Generally Accepted Good Engineering Practices (RAGAGEP) increased the scope of relief systems risk factors that require evaluation to develop complete and compliant Pressure Relief and Flare Systems documentation. Failure to comply with RAGAGEP ((d)(3)(ii)) is the most cited element of the Process Safety Management requirements. This paper discusses how RAGAGEP considerations now require evaluation and proper documentation of risk factors that are often overlooked including but not limited to: dispersion analysis, thermal radiation, noise, vibration risk, reaction forces and structural supports, metal cold temperatures due to expansion cooling and two phase flow, hot temperatures due to fire exposure and/or runaway reactions, PRV stability, chemical reaction systems, and loss of high pressure/low pressure interface. Important RAGAGEP considerations for these additional risk factors are highlighted and discussed. Recommendations are provided on how to best address these factors in the evaluation and documentation of design basis. © 2016 American Institute of Chemical Engineers Process Saf Prog 36: 18-23, 2017 [ABSTRACT FROM AUTHOR]

FLARES is an innovative project in the field of rare events searches, such as the search for the neutrinoless double beta decay. It aims at demonstrating the high potential of a technique that combines ultra-pure scintillating crystals with arrays of high performance silicon drift detectors, operated at about 120 K, to reach a 1% level energy resolution. The proposed technique will combine in a single device all the demanding features needed by an ideal experiment looking for rare events. The performance of a first production of matrices of silicon drift detectors as well as first measurements of the low temperature light yield of a selection of high purity scintillating crystals will be presented and discussed. [ABSTRACT FROM AUTHOR]

Flaring reduction has high priority as it meets both environmental and economic efficiency objectives. Flare Gas Recovery system (FGRs) reduce greenhouse gas emissions and air pollutant by recovering low pressure off gases that be flared. In the present study, the impact of FGRS include GHGs and Air pollutants emission for three different cases of flare gas system investigated. A feasibility study has been performed on implementing 3 FGRs, namley, A, B and C based on tree scenarios. Scenario 1 and 2 recommend the use of recovered gas as low and high pressure fuel gas respectively. In the scenario 3 the gas recoveried is injected to the feedstock line. For all scenarios (9 FGRs), a simulation has been conducted and the electrical consumption are determined. Then the quantitative values of the flare gas recovery, GHG emissions and air pollutants reduction of each case are calculated. Moreover, cost estimation for each scenario carried out based on the economic data extracted from Clean Development Mechanism projects. The results showed that the FGRs A, B and C seems to be able to provide 29, 16.7 and 5.3 MMSm³ each year in scenario 1 respectively, while they are slightly lower for scenario 2 and 3. Implementation of FGRs for flare A, B and C in scenario 1 consumed 2252.2, 1291.8 and 415.9 MWh/y electrical energy and other scenarios consumption is higher. The net GHG emission and air pollutants reduction of FGRs A, B and C in scenario 1 is 66479, 38175, 12315 ton CO2/y and 197, 113, 36 ton/y respectively. The best result of emission reduction is related to scenario 1, and scenario 3 has lowest emission reduction. Installing FGRs A, B and C with scenario 1can save about 2.4, 1.3 and 0.4 milion dollars each year for operation and the IRR index is about %45, %35, %19 respectively. The net present values of investment and the internal rate of return suggest that the use of FGRs in scenario 1 is economically suitable. FGRs A, B in scenario 2 have IRR index %35 and %26 which these amount are higher than interst rate. FGRs C in scenario 2 has IRR lower %15. The payback time is less than 6 year in both scenario 1 and 2 and the IRR for them is more than intrest rate 15 percent. The third scenario possesses minus IRR index and this scenarion rejected. Economic analysis showed that FGRs A, B in scenario 1 and FGRs A in scenario 2 are economic in every state certainly and even in the worst state the minimum IRR is higher than discount rate (%15). Application of FGRs C has some risk. Thus, all FGRs in the scenarios 1 and FGRs A and B in scenario 2 are economical and the highest emission reduction is related to scenario 1, but all FGRs in scenario 3 are not economic surely and dismissed. [ABSTRACT FROM AUTHOR]

Phenomenological studies relating to the oscillation of buoyant diffusion flames are very important to design flare systems in the energy and petrochemical industry or develop an image recognition algorithm for wind-aided fire detection. In this work, the oscillation frequency for the “down-wash mode” buoyant diffusion propane flames (momentum flux ratio of jet to cross-wind < 0.1, 6 × 10 −5 < Froude number of the fuel flow < 2 × 10 −2 , 10 2 < Richardson number < 10 4 ) were investigated. The experiments were conducted in a wind tunnel, and a kinematic model of the global oscillation frequency was established. The results show that: With the increasing cross-wind velocity, the flames bases are augmented by the “friction force” to cover more area of the near wake of the nozzle, with more length and area of the continuous regions of the flame. Coupling the influences of buoyancy acceleration, entrainment deceleration and “friction force” on the axial fuel velocity, the formula of the puffing frequency was deduced through introducing a buoyancy and friction force related coefficient and a decay coefficient that employs the entrainment deceleration of the axial velocity. This model was validated by the experimental results with good agreements. The flame frequency increases with increasing velocity ratio of cross-wind to jet flow. The decay coefficient is less than unity, ensuring longer flow times, enabling the theoretical model to have a good predictive capability. [ABSTRACT FROM AUTHOR]

This article analyzed the potential energy recovery from rather small quantities of associated gas (<2000 m3/h), where the on-site electricity generation within the oil extraction field may represent a cost-effective solution as an alternative to flare combustion. Various power plant technologies were considered and compared from both the economic and avoided CO2emissions points of view. It turned out that adopting a scheme with non-derated internal-combustion engines (ICE) fed by treated gas, and partial gas flaring, the most cost-effective result was obtained, showing a payback time of about 5 years and an internal rate of return (IRR) of 42.2%. [ABSTRACT FROM PUBLISHER]

This review paper summarizes process safety aspects of abnormal situations and incidents in industrial facilities. Major accidents and their negative impacts on health, safety and environment have shown the importance of enhancing safety culture, understanding causes of abnormal situations and determine effective management strategies. Flaring is a safety industry practice to control and manage processes during normal and abnormal operations. This paper identifies current efforts made by industry and researchers toward better management of abnormal situation for flare reductions. These efforts came about because of current and impending environmental legislation. The paper finds that future strategies developed for ASM must consider safety as well as environmental and economic implications; and it highlights the challenges and future guidelines for safer abnormal situation management. [ABSTRACT FROM AUTHOR]

Flare minimization (FM) in chemical process industry (CPI) under abnormal operating conditions such as plant start-ups, shut-downs, and process upsets can significantly reduce plant emissions, which suggests tremendous raw material and energy savings for plant, as well as substantial environmental and societal benefits. In this paper, a systematic methodology based on plant-wide dynamic simulation is presented for safety-oriented CPI FMs under abnormal operating conditions. Since off-specification emission sources are inevitable during abnormal operating conditions, to significantly reduce flaring emission in a chemical plant, they must be either recycled to the upstream process for online reuse, or stored somewhere temporarily for future reprocessing. Thus, the off-spec products could be reused instead of being flared. Together with the new development of FM operating strategies, rigorous dynamic simulation based safety checks are also highlighted in the presented methodology. Two case studies on FMs for start-up and shut-down operations of an ethylene plant have been employed to demonstrate the efficacy of the proposed study. [ABSTRACT FROM AUTHOR]

Gas flaring accelerates climate change with greenhouse gases but also harms the environment with other pollutants such as H 2 S, carbon sulfides, NO x and metals. Methane is a valuable energy vector and converting the associated gas from thousands of wells to liquid fuels would reduce the environmental footprint of oil field operations. Micro-gas-to-liquids technology (GtL) reduces flared natural gas and emissions while producing valuable diesel. Integrating a high pressure syngas step with Fischer–Tropsch (FT) in a single vessel reduces investment and operating costs, which is now an insurmountable hurdle that face producers exploiting wells far from gas pipeline infrastructure. We have demonstrated that coupling these two technologies produces C 7+ liquid. Furthermore, the high pressure POX reactor can convert 96% of the methane while producing a H 2 /CO ratio of 2, which is ideal for FT, at 900 °C. With a capacity of 100 MCF d −1 , one micro-refinery unit can reduce CO 2 emissions by1.2 kt y −1 . [ABSTRACT FROM AUTHOR]

The high price of crude oil, strict environmental regulations and ever-increasing demand for energy have made refineries adopt a more holistic approach to integrating energy, economics and environment in their design and operation. Gas flaring is a major factor for the wastage of energy in oil and gas industries that could be better utilized and even generates revenue. Integration and use of wasted and flared gases with fuel gas network (FGN) is an effective approach for reducing GHG emissions as well as conserving energy in refineries. In this paper, current FGN model introduced by Hassan et al. was modified and also a novel methodology was presented for grass-root and retrofit design of FGNs using integration of flare gas streams. GHG emission concept is added to the base model as new constraint to control and minimize the flaring. A FGN proposed for a refinery case study with integration of flare gas streams indicated a 12% reduction in natural gas consumption compared to the non-integrated flare gas stream case and a 27.7% reduction compared to the base case with no FGN. In the retrofit case, results suggested that the maximum utilization of flare gas streams can be the most profitable solution. [ABSTRACT FROM AUTHOR]

Flare gas recovery is one of the most attractive methods to improve energy efficiency in oil refineries to decrease greenhouse gas emissions. The recovered gas is used to feed refinery processes, granting advantages in terms of fuel economy and flare stress. This paper presents the results obtained by a feasibility study of a flare gas recovery system in a real refinery; the work focused on: i) the choice and the design of the flare gas recovery system; ii) the gas treatment and reuse; iii) the economic feasibility, and the payback period. An experimental campaign has been performed to evaluate both the composition and the flow rate of the flare gas. Results showed that the flare gas had a strongly variable flow rate and composition due to the different gas species processed in refinery. A methodology for the system selection is presented: a 400 kg/h liquid ring compression device is chosen; its basic design is described as well as the chemical treatments of inert gases and hydrogen sulphide (H 2 S). The yearly energy recovery was estimated to be 2900 TOE, corresponding to 6600 tons of CDE (Carbon Dioxide Equivalent). Finally, an economic evaluation was carried out, showing a payback period of about 2.5 years. [ABSTRACT FROM AUTHOR]

Critical operations of chemical process industry (CPI) plants such as ethylene plant shutdowns could emit a huge amount of VOCs and NOx, which may result in localized and transient ozone pollution events. In this paper, a general methodology for studying dynamic ozone impacts associated with flare emissions from ethylene plant shutdowns has been developed. This multi-scale simulation study integrates process knowledge of plant shutdown emissions in terms of flow rate and speciation together with regional air-quality modeling to quantitatively investigate the sensitivity of ground-level ozone change due to an ethylene plant shutdown. The study shows the maximum hourly ozone increments can vary significantly by different plant locations and temporal factors including background ozone data and solar radiation intensity. It helps provide a cost-effective air-quality control strategy for industries by choosing the optimal starting time of plant shutdown operations in terms of minimizing the induced ozone impact (reduced from 34.1 ppb to 1.2 ppb in the performed case studies). This study provides valuable technical supports for both CPI and environmental policy makers on cost-effective air-quality controls in the future. [ABSTRACT FROM AUTHOR]

The amount of heat radiated by flares is important for designing and locating flare systems. No methods are described in the literature for predicting radiation of enclosed ground flares. To investigate radiation of enclosed ground flares, a series of gas flares were simulated in this work by computational fluid dynamics (CFD). The radiation values derived by CFD simulation match the experimental data. For methane, propane, and butane flaring, the radiation flux of 15.77 kW/m was attained only above the flare system, so radiation will not affect the integrity of the structures. The radiation flux at the ground level was below 1.58 kW/m, so this area is safe for personnel. For hydrogen, the radius of isopleth of radiation flux of 15.77 kW/m can reach 33 m, so towers and elevated structures should not be located in these areas. The radius of isopleth of radiation flux of 6.31 kW/m can reach 70 m, and on the ground the radius of isopleth of 1.58 kW/m radiation flux can reach 120 m. Radiation decreases with increase in enclosed ground flare height, so the safe distance of enclosed ground flare can be reduced by increasing the ground flare height. [ABSTRACT FROM AUTHOR]

A new gas flaring emission parameterization has been developed which combines remote sensing observations using VIIRS nighttime data with combustion equations. The parameterization has been applied to southern West Africa, including the Niger Delta as a region which is highly exposed to gas flaring. Two two-month datasets for June–July 2014 and 2015 were created. The parameterization delivers emissions of CO, CO2, NO and NO2. A flaring climatology for both time periods has been derived. The uncertainties owing to cloud cover, parameter selection, natural gas composition and the interannual differences are assessed. Largest uncertainties in the emission estimation are linked to the parameter selection. By using remote sensing cloud cover observations, a correction factor for the climatology was established to consider the effect of flares masked by clouds. It can be shown that the flaring emissions in SWA have significantly decreased by 30 % from 2014 to 2015. Existing emission inventories were used for validation. CO2 emissions with the estimated uncertainty in brackets of 8 (12/2) Tg y−1 for 2014 and 5 (7/1) Tg y−1 for 2015 are derived. The flaring emission estimation within this study for June–July 2014 is in the same order of magnitude compared to existing emission inventories. For the same period in 2015 the emission estimation is one order of magnitude smaller in comparison to existing inventories. The deviations might be attributed to uncertainties in the derived flare gas flow rate, the decreasing trend in gas flaring or inconsistent emission sector definitions. The parameterization source code is available as a package of R scripts. [ABSTRACT FROM AUTHOR]

After a brief review of the global gas flaring and venting in oil industries including the emission of air pollutants and greenhouse gases and the amount of energy resources wasted, the focus is on Iran as a major oil producing and the world's third largest gas flaring country. Gas flaring is also practiced in natural gas industries, petroleum refining and petrochemical plants, although the level of emission is very low compared with emissions from oil production. The historical emission of these gases globally and Iran specifically, geographic location of emission sources, composition of gases, environmental impacts of gas flaring and the current and future projects to mitigate emissions are evaluated and discussed. Emission factor, an indication of efficiency in oil production, varies widely among oil production sites around the world, from near zero to more than 50 standard cubic meters of flare gas per barrel of oil produced with an average value of about 5. Iran's emission factor has fluctuated from around 1 to more than 16 according to the data of 1980–2012 with higher emission factors for offshore oil production. Data also show an increasing trend during 2010–2012 which could be due to the several technical reasons in oil productions as well as economic sanctions imposed on Iran. In addition, there is a great amount of uncertainty and discrepancies among various data sources in the emission factors due to the lack of actual measurements of the volume and composition of flare gas and the uncertainties in the data sources. This requires regulatory measures, investment by oil companies and international collaboration. The economic and technological constraints in implementing or delaying the gas flare reduction projects are evaluated and addressed, with successful case studies and best practices reviewed. In particular, the techno-economic constraints in implementing gas flaring reduction projects caused by international sanctions on Iran are analyzed. It is shown that despite the great loss of energy resources due to gas flaring, its adverse impacts on the local and global environment and the availability of the technologies to reduce emissions, flaring is still practiced in many parts of the world, which can be avoided if the necessary regulatory policies and measures are established at national levels and international collaboration can facilitate the investment by providing the required finance and technologies. At present the international activities to implement gas flaring project activities under the Clean Development Mechanism (CDM) of the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC) are very limited, but could be very effective in reducing emissions, if implemented. Due to the global demand and continued use of oil and gas in the next decades, there is an urgent need for reducing gas flaring emissions. This is not only the responsibility of the oil and gas companies, but also the responsibility of the national governments and the global community. [ABSTRACT FROM AUTHOR]

Women have played a prominent role in environmental preservation in all societies, including societies facing serious environmental problems. Women in places like Nigeria's Niger Delta carry out tasks such as farming, fetching of firewood for domestic use, fetching of water, and the like. These activities involve the use of natural resources and thus make women more vulnerable when there are problems such as oil pollution, gas flaring, and other related activities that endanger the environment. In the Niger Delta women have protested against oil related activities that damage their environment. They have also participated in other events to conserve their environment. The paper adopts an ecofeminist perspective in critiquing environmental mismanagement in the Niger Delta. It highlights the fact that women are prominent in campaigning for a sustainable Niger Delta. There is need for writers from academic and social circles writing on the Niger Delta not to ignore the women's voices. [ABSTRACT FROM AUTHOR]

Emissions released into the atmosphere from gas flaring in the Niger Delta Region (NDR) of Nigeria have adversely affected the environment and well-being of the inhabitants. This present study aimed at employing the emission inventory of flared gas in this region to assess the level of achievement of Millennium development goal (MDG) 7 with respect to sustainable environment. Greenhouse gas (GHG) and black carbon (BC) inventory of the region was estimated from gas flared data sourced from Nigeria National Petroleum Corporation using empirical formula and emission factors obtained from literature. For the period in view (1990-2014), a total estimate of 1.80 x 109 tons of CO2 equivalent (tCO2 e) was released into the atmosphere from the flaring of 555.74 Bcm of gas. Relative uncertainty of the emission was between -92.2% and 51.16%. It was observed that the present (2014) quantity of emissions has reduced by 49.71% (3.61 x 107tCO2 e) compared to the emissions (7.26 x 107tCO2 e) for the year 1990. The results showed that MDG-7 on environmental sustainability in the NDR is progressing well with considerable emission reduction achieved through increased utilization of gas in the country to reduce the volume of gas flared. [ABSTRACT FROM AUTHOR]

A new method has been developed for a direct and remote measurement of industrial flare combustion efficiency (CE). The method is based on a unique hyper-spectral or multi-spectral Infrared (IR) imager which provides a high frame rate, high spectral selectivity and high spatial resolution. The method can be deployed for short-term flare studies or for permanent installation providing real-time continuous flare CE monitoring. In addition to the measurement of CE, the method also provides a measurement for level of smoke in the flare flame regardless of day or night. The measurements of both CE and smoke level provide the flare operator with a real-time tool to achieve “incipient smoke point” and optimize flare performance. The feasibility of this method was first demonstrated in a bench scale test. The method was recently tested on full scale flares along with extractive sampling methods to validate the method. The full scale test included three types of flares – steam assisted, air assisted, and pressure assisted. Thirty-nine test runs were performed covering a CE range of approximately 60-100%. The results from the new method showed a strong agreement with the extractive methods (r2=0.9856 and average difference in CE measurement=0.5%). Implications: Because industrial flares are operated in the open atmosphere, direct measurement of flare combustion efficiency (CE) has been a long-standing technological challenge. Currently flare operators do not have feedback in terms of flare CE and smoke level, and it is extremely difficult for them to optimize flare performance and reduce emissions. The new method reported in this paper could provide flare operators with real-time data for CE and smoke level so that flare operations can be optimized. In light of EPA’s focus on flare emissions and its new rules to reduce emissions from flares, this policy-relevant development in flare CE monitoring is brought to the attention of both the regulating and regulated communities. [ABSTRACT FROM PUBLISHER]