Emissions of volatile organic compounds during the ship-loading of petroleum products: Dispersion modelling and environmental concerns

Systematic review on benzene, toluene, ethylbenzene, and xylene (BTEX) emissions; health impact assessment; and detection techniques in oil and natural gas operations

The ONG industry emits VOC such as BTEX, which pose health risks to workers. This study analyzed peer-reviewed research articles to provide BTEX emission profiles from three primary ONG operations and their associated health risks. PRISMA (Preferred Reporting Items for Systematic Reviews) was used to choose relevant articles for this review paper. The analysis revealed that in ONG operation, upstream operations involving gas flaring (benzene: 0.115 ± 0.1 ppmv, toluene: 0.029 ± 0.001 ppmv, ethylbenzene: 0.002 ± 0.001 ppmv, xylene: 0.123 ± 0.001 ppmv) contributed to relatively lower concentration of BTEX emission. Meanwhile, midstream operation involving tanker loading (benzene: 5.391 ± 28.670 ppmv, toluene:10.376 ± 48.929 ppmv, ethylbenzene:1.583 ± 6.563 ppmv, xylene:2.067 ± 9.211 ppmv) contributed to significant BTEX emission. On the other hand, downstream operations involving refinery operation zone (benzene: 3.5 ± 1.69 ppmv, toluene: 4 ± 0.87 ppmv, ethylbenzene: 1.2 ± 0.24 ppmv, xylene: 6.6 ± 1.34 ppmv) and refueling station (benzene: 1.164 ± 0.408 ppmv, toluene: 2.394 ± 1.086 ppmv, ethylbenzene: 1.301 ± 0.779 ppmv, xylene: 1.736 ± 0.898 ppmv) exhibited higher BTEX emissions. The Lifetime Cancer Risk (LCRi) for benzene was greater than 10-6 near gasoline pump stations (1400 × 10-6) and during loading operations (160 × 10-6). Ethylbenzene also had a significant LCRi value of 1000 × 10-6 during loading operations. Other ONG activities like gas flaring, inspection operations, and gasoline station pumps have hazard ratio value of > 1. The study highlights BTEX emissions in all three ONG sectors, with significant contributions from midstream tanker loading and downstream refinery and refueling stations. E-nose techniques are promising for BTEX detection due to their real-time measurement capabilities and ease of use. Some Asian countries have reported benzene concentrations exceeding permissible limits during tanker loading and refueling operations. Overall, BTEX emissions are a cause for concern and should be addressed in ONG operations.

Utilizing a optimized method for evaluating vapor recovery equipment control efficiency and estimating evaporative VOC emissions from urban oil depots via an extensive survey

As an important intermediary between upstream refineries and downstream urban gas stations, volatile organic compound (VOC) emissions from urban oil depots were often disregarded, underestimating their environmental and health implications. An extensive investigation of urban depots' fuel composition and operational dynamics was conducted nationwide. We developed a novel approach that integrates theoretical models with easily measurable operational data from the depots to evaluate the efficiency of post-treatment devices in actual situations. Even in well-managed oil depots, the actual control efficiency of vapor recovery units fluctuates between 63 % and 85 %, depending on the concentration of hydrocarbon vapors in the intake of the device. The national emission factors for gasoline, diesel, and aviation kerosene at a national level were 6.64 ± 1.16, 2.07 ± 0.42, and 6.17 ± 1.05 tons per 10,000 tons, respectively. In 2019, China's urban oil depots emitted 165 thousand tons of VOC. Enhancing control strategies by optimizing the physical and chemical parameters of refined oil, improving storage capacity and turnover efficiency, and upgrading storage tanks had the potential to reduce emissions by more than 60 %. However, a 30 % failure rate in these systems could negate the benefits of these improved strategies.

Estimating the health and economic burden of shipping related air pollution in the Iberian Peninsula

Air pollution is the leading cause of the global burden of disease from the environment, entailing substantial economic consequences. International shipping is a significant source of NO_x, SO₂, CO and PM, which can cause known negative health impacts. Thus, this study aimed to estimate the health impacts and the associated external costs of ship-related air pollution in the Iberian Peninsula for 2015. Moreover, the impact of CAP2020 regulations on 2015 emissions was studied. Log-linear functions based on WHO-HRAPIE relative risks for PM_2.5 and NO₂ all-cause mortality and morbidity health end-points, and integrated exposure-response functions for PM_2.5 cause-specific mortality, were used to calculate the excess burden of disease. The number of deaths and years of life lost (YLL) due to NO₂ ship-related emissions was similar to those of PM_2.5 ship-related emissions. Estimated all-cause premature deaths attributable to PM_2.5 ship-related emissions represented an average increase of 7.7% for the Iberian Peninsula when compared to the scenario without shipping contribution. Costs of around 9 100 million € yr-1 (for value of statistical life approach - VSL) and 1 825 million € yr^-1 (for value of life year approach - VOLY) were estimated for PM and NO₂ all-cause burden of disease. For PM_2.5 cause-specific mortality, a cost of around 3 475 million € yr^-1 (for VSL approach) and 851 million € yr^-1 (for VOLY approach) were estimated. Costs due to PM and NO₂ all-cause burden represented around 0.72% and 0.15% of the Iberian Peninsula gross domestic product in 2015, respectively for VSL and VOLY approaches. For PM_2.5 cause-specific mortality, costs represented around 0.28% and 0.06%, respectively, for VSL and VOLY approaches. If CAP2020 regulations had been applied in 2015, around 50% and 30% respectively of PM_2.5 and NO₂ ship-related mortality would been avoided. These results show that air pollution from ships has a considerable impact on health and associated costs affecting the Iberian Peninsula.

Analysis of Influence of Floating-Deck Height on Oil-Vapor Migration and Emission of Internal Floating-Roof Tank Based on Numerical Simulation and Wind-Tunnel Experiment

Internal floating-roof tanks (IFRTs) are widely used to store light oil and chemical products. However, if the annular-rim gap around the floating deck becomes wider due to abrasion and aging of the sealing arrangement, the static breathing loss from the rim gap will be correspondingly aggravated. To investigate the oil-vapor migration and emissions from an IFRT, the effects of varying both the floating-deck height and wind speed on the oil-vapor diffusion were analyzed by performing numerical simulations and wind-tunnel experiments. The results demonstrate that the gas space volume and the wind speed of an IFRT greatly influence the vapor-loss rate of the IFRT. The larger the gas space volume, the weaker the airflow exchange between the inside and outside of the tank, thereby facilitating oil-vapor accumulation in the gas space of the tank. Furthermore, the loss rate of the IFRT is positively correlated with wind speed. Meanwhile, negative pressures and the vortexes formed on the leeward side of the tank. In addition, the higher concentration areas were mainly on the three vents on the downwind side of the IFRT. The results can provide important theoretical support for the design, management, and improvement of IFRTs.

Emissions of volatile organic compounds from crude oil processing - Global emission inventory and environmental release

Airborne Volatile organic compounds (VOCs) are known to have strong and adverse impacts on human health and the environment by contributing to the formation of tropospheric ozone. VOCs can escape during various stages of crude oil processing, from extraction to refinery, hence the crude oil industry is recognised as one of the major sources of VOC release into the environment. In the last few decades, volatile emissions from crude oil have been investigated either directly by means of laboratory and field-based analyses, or indirectly via emission inventories (EIs) which have been used to develop regulatory and controlling measures in the petroleum industry. There is a vast amount of scattered data in the literature for both regional emissions from crude oil processing and scientific measurements of VOC releases. This paper aims to provide a critical analysis of the overall scale of global emissions of VOCs from all stages of oil processing based on data reported in the literature. The volatile compounds, identified via EIs of the crude oil industry or through direct emissions from oil mass, are collected and analysed to present a global-scale evaluation of type, average concentration and detection frequency of the most prevalent VOCs. We provide a critical analysis on the total averages of VOCs and key pieces of evidence which highlights the necessity of implementing control measures to regulate crude oil volatile emissions (CVEs) in primary steps of extraction-to-refinery pathways of crude oil processing. We have identified knowledge gaps in this field which are of importance to control the release of VOCs from crude oil, independent of oil type, location, operating conditions and metrological parameters.

Emissions of intermediate volatility organic compound from waste cooking oil biodiesel and marine gas oil on a ship auxiliary engine

Ship auxiliary engines contribute large amounts of air pollutants when at berth. Biodiesel, including that from waste cooking oil (WCO), can favor a reduction in the emission of primary pollutant when used with internal combustion engines. This study investigated the emissions of gaseous intermediate-volatile organic compounds (IVOCs) between WCO biodiesel and marine gas oil (MGO) to further understand the differences in secondary organic aerosol (SOA) production of exhausts. Results revealed that WCO exhaust exhibited similar IVOC composition and volatility distribution to MGO exhaust, despite the differences between fuel contents. While WCO biodiesel could reduce IVOC emissions by 50% as compared to MGO, and thus reduced the SOA production from IVOCs. The compositions and volatility distributions of exhaust IVOCs varied to those of their fuels, implying that fuel-component-based SOA predicting model should be used with more cautions when assessing SOA production of WCO and MGO exhausts. WCO biodiesel is a cleaner fuel comparing to conventional MGO on ship auxiliary engines with regard to the reductions in gaseous IVOC emissions and corresponding SOA productions. Although the tests were conducted on test bench, the results could be considered as representative due to the widely applications of the test engine and MGO fuel on real-world ships.