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Control of Emissions from Stationary Sources
Published in Wayne T. Davis, Joshua S. Fu, Thad Godish, Air Quality, 2021
Wayne T. Davis, Joshua S. Fu, Thad Godish
Limestone is considerably less soluble in H2O compared with lime. It is also less expensive. Sulfur dioxide is removed from calcium-based wet scrubbers in a complex set of chemical equilibrium reactions that involve the absorption of gaseous sulfur oxides into the liquid phase in the wet scrubber; hydrolysis of the sulfur oxides; dissolution of the solid phase limestone (CaCO2) or lime (Ca(OH)2); acid-base neutralization; the stripping of CO2 in the case of the limestone scrubber; formation of calcium sulfite/sulfate reaction products in the liquid; precipitation of the calcium sulfite/sulfates from the scrubbing solution in the primary scrubber or in a secondary oxidation tank; separation of the reacted products; and final disposal/use of the precipitated products. The overall initial reactions can be summarized by the following overly simplified equations:
The response of C/N/S cycling functional microbial communities to redox conditions in shallow aquifers using in-situ sediment as bio-trap matrix
Published in Environmental Technology, 2023
Cui Li, Rong Chen, Weiwei Ouyang, Chen Xue, Minghui Liu, Hui Liu
The relative abundance of Epsilonbacteraeota (0.8–20.9%, dominated by the class of Campylobacteria) remarkably increased in well RE2, which comprises a diverse group of organisms, including carbon fixation, nitrate reduction, ammonification, and sulfur oxidation [37]. The relative abundance of Actinobacteria (2.4–87.1%, first eight days, dominated by the class of Actinobacteria) showed a sudden increase and disappeared in day 12, and Firmicutes (2.7–80.9%, dominated by the classes of Bacilli and Clostridia) remarkably increased in well RE3, and decreased in well RE1 and RE2. Actinobacteria and Firmicutes are widely involved in nitrate reduction [38], and Firmicutes could respire sulfate, sulfite, or thiosulfate [33]. The relatioship between increase and decrease of Actinobacteria and Firmicutes in RE3 demonstrates that the microbial functions are nitrate reduction in the first eight days, regulated mainly by Actinobacteria, and then transfers to sulfate reduction, primarily controlled by Firmicutes. Additionally, Actinobacteria, Acidobacteria and Proteobacteria have been reported to be related to polycyclic aromatic hydrocarbons and complex organic matter degradation [39, 40]. Organohalide-respiring bacteria are mainly found within the phyla Proteobacteria and Firmicutes [9, 41, 42]. The changes in the relative abundances of the major phyla and classes revealed the effects of redox conditions on sediment microbial communities.
Overcoming the rheological performance and density limitations using a novel high density magnesium bromide based completion fluid in oil and gas reservoirs
Published in Petroleum Science and Technology, 2023
Ramanand Singh, R. Sharma, G. Ranga Rao
In the case of compatibility with formation water, the main worry here is the development of scale because of synthetic responses between completion fluid and formation water (Hossain and Al-Majed 2015). Calcium-based completion fluids are also susceptible to the precipitation of insoluble salts with solutions containing sulfate, sulfite, carbonate, bicarbonate, and fluoride. Therefore, if the application involves connate waters high in these ions, particularly sulfate, then the compatibility of the clear fluid with the connate water should be checked before use (Place, Paul, and Sigalas 1980). Incompatibility with formation waters leads to a potential cause of formation-related damage with high-density brine completion fluids and specific care should be taken to prevent the mixing of seawater (high in SO4) with high-density brines (Morgenthaler 1986). In most cases, formation damage can happen due to the wrong implementation of this fluid behavior (Singh, Sharma, and Rao 2022a). Calcium-based fluids tend to gypsum formation at offshore water reactions. Scale is formed into tubular, casing due to gypsum (CaSO4) formation, which will lead to finally formation damage (Place, Paul, and Sigalas 1980; Frenier and Ziauddin 2008).
Production and purification of anhydrous sodium sulfide
Published in Journal of Sulfur Chemistry, 2021
William H. Smith, Jerry Birnbaum, Colin A. Wolden
A low-grade form of Na2S is also produced as a byproduct of several industrial processes, including caustic scrubbing of natural gas and processing of sulfide-containing ores like BaS [12]. This ‘technical’ grade of Na2S is commercially available at low cost (∼$0.50 kg−1 in bulk quantities), but in the form of a hydrate (Na2S•xH2O, x∼3) that contains ∼40 wt% water. Its characteristic yellow color reflects the presence of polysulfide impurities (Na2Sx). In addition to polysulfides, this Na2S hydrate contains significant concentrations of oxysulfur impurities (Na2SOx) such as sodium sulfate, sulfite, thiosulfate, and hyposulfite. The hydrate also typically contains a high concentration of sodium hydrosulfide (NaHS). As such, this grade of Na2S finds use in applications where purity and moisture content is not of concern, such as in the Kraft process in the pulping industry or as a bleaching agent in the manufacture of textiles or rubber. Efficient purification of this low-grade form of Na2S would be an economically attractive route to anhydrous Na2S for the applications listed above.