Long-Range Transport of Sulfur Dioxide Emissions From External Sources to Tehran

Large-scale emissions of sulfur dioxide (SO2) from the combustion of heavy fuel oils are deteriorating the air quality in Tehran and regularly causing complex atmospheric pollution situations and human health concerns. Our analysis of the long-term SO2 emission data in Tehran confirmed that the magnitude of local SO2 emission sources is not adequate to reach SO2 concentrations to their present levels. Tehran is predominantly affected by regional transport of SO2 from exterior sources further away located in Iraq, Saudi Arabia, and adjacent provinces neighboring Tehran. Approximately 80% of total SO2 emissions in Tehran were observed to have impacts from the external hotspots outside of Tehran. While local emission sources only contribute around 20% of the total SO2 emissions. Bivariate polar plots, k-mean cluster, pairwise polar correlation, and PSCF analysis provided evidence for the impact of large-scale transport of SO2 emissions from external locations from the west/northwest, north/northeast, and south/southwestern areas of the region. Further observations of these hotspot areas observed in our analysis with TROPOMI satellite data confirmed significant SO2 emissions resulting from the consumption of heavy fuel oils in thermal power plants and oil/gas refineries. Overall, the results suggested that the regulatory strategies for controlling local traffic emissions of SO2 in Tehran would not be beneficial for reducing public health exposures to SO2 in Tehran. Such improvements can be attained mainly by diminishing the emission sources located further away from Tehran.

Firing Trials of the Siemens SGT-300 Dry Low Emissions Combustion System Using High Calorific Value Fuels

The current paper presents an extension of the fuel flexibility of the Siemens SGT-300 Dry Low Emissions combustion system to include High Calorific Value fuels, achieved using the engine’s current standard combustion hardware. Results from high pressure rig tests show that the standard SGT-300 DLE combustor can reliably operate on High Calorific Value fuels with temperature corrected Wobbe Index up to 63MJ/m3, which corresponds to Grade A LPG (60%vol. C3H8, 40%vol. C4H10). Metal temperatures of the combustion hardware when operating on High Calorific Value fuels are within life acceptance criteria for the Siemens SGT-300 industrial gas turbine. NOx emissions throughout the load range of the engine comply with the EU Industrial Emissions Directive. At part load, a reduced requirement for piloting compared to Natural Gas yields relatively low temperatures at the burner face and low NOx emissions. NOx emissions at full load, which tend to increase with increasing heating value, are higher than for Natural Gas but lower than for diesel and heavy fuel oils.

A Review of Cryogenics Applications for Power and Energy

Cryogenic technologies use cryogens such as natural gas, nitrogen, helium, hydrogen, argon, and oxygen as main working fluids. These cryogenic technologies and cryogens are emerging in the fields of energy storage, power generation, and eco-friendly fuels. Recently, researchers have proposed to integrate cryogenic systems with power generation systems including Nuclear power plants and wind turbines, to store surplus energy during the off-peak hours and use it during peak hours. The basic idea is to convert air or some other cryogen into liquid during the off-peak hours and expand it during the peak hours to run turbines. Whereas in the shipping industry; LNG is being considered as an alternative fuel to gasoline to meet the future emissions criteria of IMO. LNG not only reduces the vessel’s emissions but it is also cheaper than heavy fuel oils. As every technology has some pros and cons, the efficiency of cryogenics power generation systems is low; about 25%, but work is being done to improve its efficiency and to find alternative applications. This article discusses the applications, advantages, and drawbacks of cryogenics technologies and fuels for energy generation and storage applications. It also focuses on the challenges which are being faced by this technology and possible ways to overcome them.