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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
In direct injection, the reagents used are either trona (naturally occurring sodium carbonate, Na2CO3) or nahcolite (naturally occurring sodium bicarbonate, NaHCO3). These dry aerosol particles react with SO2, and the fly ash particles are collected on baghouse filters downstream. The PM deposited on the filters serves as a porous reagent bed that converts SO2 to sodium sulfite (Na2SO3) and sodium sulfate (Na2SO4).
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Published in Mary K. Theodore, Louis Theodore, Introduction to Environmental Management, 2021
Dry-injection processes generally involve pneumatic introduction of a dry, powdery alkaline material, usually a sodium-based sorbent (sodium bicarbonate, trona, or nahcolite), into the flue gas stream with subsequent fabric filter collection. The injection point in such processes can vary from the boiler-furnace area all the way to the flue gas entrance to the baghouse, depending on operating conditions and design criteria. This process has the advantage of being very simple, mechanically, with almost no increase in the pressure drop of the system. The disadvantage that the dry-injection process has is that gas–solid mass transfer is much slower than gas–liquid mass transfer. Therefore, the acid gas removal for dry injection is much lower than that achieved with spray dryer or CDS systems.
Industrial minerals
Published in Francis P. Gudyanga, Minerals in Africa, 2020
Natron is an admixture of sodium carbonate decahydrate Na2CO3·10H2O, sodium bicarbonate NaHCO3 together with small quantities of sodium chloride and sodium sulphate. It occurs in saline lake beds in association with thermonatrite, nahcolite, trona, halite, mirabilite, gaylussite, gypsum, and calcite. It is the source of soda ash (sodium carbonate anhydrate N a2CO3) as a result of calcination.
Accelerator Technology for Well Logging: Advances, Challenges, and Opportunities
Published in Nuclear Science and Engineering, 2023
In addition, as we noted previously, the photon yield for a given element, reflecting its concentration, can arise from its various sources in the geology. Thus, as we saw in the case of determining the oil saturation in CaCO3 reservoirs, the carbon from the rock must be accounted for. Similarly, to determine the total organic carbon (TOC) volume from kerogen [(CH2)6], the key source of hydrocarbon in oil shales, one would need to account for the inorganic carbon contained in rocks such as CaCO3, dolomite, dawsonite [NaAl(CO3)(OH)2], nahcolite (NaHCO3), etc., that may be present in the reservoir.50 This is done by determining the yields of the elements in these rocks using the methodology in Ref. 28, briefly described in Appendix B.
Salt Decay and Salt Mixtures in the Architectural Heritage: A Review of the Work of Arnold and Zehnder
Published in International Journal of Architectural Heritage, 2022
The potential effect of modern building materials as sources of salts is an aspect the two authors give plenty attention to. Indeed, materials with a high alkali content such as Portland cement, but also waterglass, siliconates and alkaline cleaning products, can give rise to three main kinds of chemical reactions from which soluble salts, carbonates, sulfates, nitrates and chlorides, are formed (Arnold 1981, 1995; Arnold and Zehnder 1991): the alkali in these materials react with the carbonic acid formed in moist walls when the air CO2 reacts with water, thus giving rise to alkali carbonates such as natrite, thermonatrite, nahcolite, trona or kalicinite;the alkali carbonates can further react with an acid atmosphere, producing sulfates of sodium and potassium;the alkali carbonates can also react with autochthonous salts in the wall, namely sulfates, nitrates and chlorides of magnesium and calcium, thereby forming sulfates, nitrates and chlorides of sodium and potassium, as well as magnesium carbonates such as hydromagnesite and nesquehonite; the new salts are more harmful than the native nitrates and chlorides of magnesium and calcium as the later are highly hygroscopic and therefore cannot crystallize under normal conditions.
Contrasting geology and mineralogy of evaporative encrustations in salt-tolerant ecosystems, Maniototo basin, Central Otago, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2022
Dave Craw, Cathy Rufaut, Gemma Kerr, Dhana Pillai
A notable feature of evaporative marine aerosol waters is the relatively high pH of >9 (Figure 9B; Table 2). Modelling equilibrium evaporative precipitation from the Sutton Salt Lake water in equilibrium with atmospheric CO2 yields pH initially near 7, followed by a progressive decrease (Figure 9B). However, if the major carbonate minerals are suppressed as in the model in Figure 9A, the initial pH is near to 9 as observed (Table 2), although this model pH also decreases with progressive evaporation (Figure 10B). Higher pH results from models in equilibrium with lower CO2 concentrations, although these decrease with on-going evaporation as well (Figure 10B). An alternative explanation for high pH in partially evaporated waters is preferential dissolution of Na-carbonate minerals (Figure 4E; 9A,B). Modelling suggests that this effect is slight when involving nahcolite, but substantial when involving trona or natron (Figure 9A,B).