Search Results (2)

Various authors have highlighted the possible removal of methane from the atmosphere via oxidation by broad releases of iron salt aerosols in order to serve climate protection goals. This technique is known as enhanced atmospheric methane oxidation (EAMO). This study proposes and employs a modeling approach for the potential environmental impacts associated with a hypothetical small-scale field test of EAMO consisting of seeding cargo-ship exhaust plumes with iron salt aerosols. Using a sample region in the Southern Caribbean Sea as a hypothetical testing site, it provides assessments of potential impacts to air quality, human health, and the marine environment. The modeling focuses on the incremental difference between conducting the hypothetical field test and a no-action scenario. The model results are compared to ambient air standards and pertinent screening thresholds, including those associated with pertinent health risk metrics. The overall loading to the marine environment is contrasted against background rates of iron deposition to the marine surface. No significant impacts were identified in this assessment. The hypothetical atmospheric emissions of both FeCl₃ and HCl that the ship’s crew may be exposed to remained below governmental guidance levels. The potential deposition of FeCl₃ to the marine environment was found to be very minor in relation to the natural contributions experienced within the Southern Caribbean. Similarly, HCl deposition was assessed for potential impacts to the marine environment but was found to have no significant impact. Full article

The slagging and fouling characteristics of the heat recovery steam generator (HRSG) for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the ash samples. The results show that low melting point salt Na₂SO₄ and composite salts Na (AlSi₃O₈) and 3K₂SO₄·CaSO₄ deposit on the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas adhere to the slag surface to form a thicker slag. Low melting point composite salt NaO·Al₂O₃·SiO₂ is absorbed on the evaporator tube walls in aerosol form. With the deposition of NaO·Al₂O₃·SiO₂, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the large iron-rich slag particles are easily deposited on tube walls and fin surfaces, which is advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that easily adhere to other particles or tube walls, which facilitates the slagging and fouling process. Full article