The rapid decrease in Arctic sea ice is motivating development and increasing oil and gas extraction activities. However, few observations of these local Arctic emissions exist, limiting the understanding of impacts on atmospheric composition and climate. To address this knowledge gap, the chemical composition of atmospheric aerosols was measured within the North Slope of Alaska oil fields during August and September 2016 using an aerosol time-of-flight mass spectrometer (ATOFMS) and a time-of-flight aerosol chemical speciation monitor (ToF-ACSM). Plumes from oil and gas extraction activities were characterized by soot internally mixed with sulfate (matching diesel soot) and organic carbon particles containing aminium sulfate salts. Sea spray aerosol at the coastal site was frequently internally mixed with sulfate and nitrate, from multiphase chemical processing from elevated NOx and SO2 within the oil field. Background (nonplume) air masses were characterized by aged combustion aerosol. No periods of 'clean' (nonpolluted) Arctic air were observed. The composition of the nonrefractory aerosol measured with the ACSM was similar during plume and background periods and was consistent with the mass concentrations of nonrefractory particles measured by ATOFMS. Two ultrafine aerosol growth events were observed during oil field background periods and were correlated with fine mode amine- containing particles.

Guo, D., Ou, W., Ning, F., Fang, B., Liu, Z., Fang, X., Lu, W., Zhang, L., Ud Din, S., He, Z., 2020. The effects of hydrate formation and dissociation on the water-oil interface: Insight into the stability of an emulsion. Fuel 266, 116980.

http://www.sciencedirect.com/science/article/pii/S0016236119323737 Understanding of the stability of oil-dominated emulsion, such as the oil-based drilling fluids and crude oils, is of great importance to control the gas hydrate risk management when gas hydrates formation and dissociation occurs in the emulsion. Here, a high-pressure optical capillary cell with micro-Raman spectroscopy is utilized to investigate the effects of hydrate formation and dissociation on the stability of a simulated oil-water emulsion and the micro kinetics near the oil/water interface. Both the hydrate formation and dissociation processes are stimulated in water phase near the oil-water interface. The results show that the oil can enter the water phase from the oil phase with the oil-water interface failure when hydrates rapidly growth very close to the water-oil interface, even resulting in a series of oil droplets in the water phase (oil-droplet trajectory). The interesting phenomenon are mainly caused by the concentration gradient of methane and the Marangoni effect. Subsequently, the hydrate phase dissociates, a new stable water-oil interface presents when the system becomes rebalanced. The methane diffusion behavior induced by the chemical potential gradient in hydrate formation and dissociation processes could affect the stability of the emulsion. In addition, a more profound conceptual hydrate-induced destabilization model for different types of oil-water emulsions is proposed. This study can provide a theoretical and experimental basis for the safe implementation for deep-water oil and gas drilling, hydrate drilling in permafrost and multiphase mixing transportation in pipelines.

Guo, H., Chen, C., Liang, W., Zhang, Y., Duan, K., Zhang, P., 2020. Enhanced biomethane production from anthracite by application of an electric field. International Journal of Coal Geology 219, 103393.

http://www.sciencedirect.com/science/article/pii/S0166516219309012 The utilization of biogenic coalbed methane (CBM) meets the increasing demand of energy and reduces the impact of greenhouse gases on the environment. Application of an electric field is a promising technology to increase biomethane production from various complex organic compounds. Here, the effects of an applied voltage (0.6 V, 1.2 V, and 1.8 V) on methane production due to coal biodegradation, as well as the structure of microflora and intermediates were studied by anaerobic culture, pyrosequencing, and GC - MS. The maximum methane production was observed at 1.2 V with an average of 63.0 μmol/g of coal, which was 134% higher than the control without electrodes (26.9 μmol/g of coal). The CO yield was negatively correlated with the methane 2 yield, suggesting that more carbon in coal has been transferred to methane after application of an electric field. The pyrosequencing results showed that the abundance of bacteria with extracellular electron transfer abilities, Soehngenia Desulfovibrio Deferrisoma such as , , and , increased after applying a 1.2 V electric field. Moreover, Mortierella the structure of the fungal communities changed significantly, especially the abundance of , Thielavia, Humicola Plectosphaerella , and . According to the GC-MS results, most of the products detected at the end of the cultivation period in the control were not detected in the cultures cultivated at 1.2 V. New organic