Acid plants carbon concentrations

In sulfuric acid production, acid brick lining of membrane coated mild steel tanks and reaction vessels is considered the most durable and versatile construction material for the sulfuric acid plant. Such linings wiil reduce the steel shell temperature and prevent erosion of the normally protective iron sulfate film that forms in stagnant, concentrated (oxidizing) sulfuric acid. Dilute (red uC ing) sulfuric acid solutions are very corrosive to carbon steel, which must be protected by impermeable (e.g., elastomeric) membranes and acid brick lining systems. Such acid brick linings often employ membranes comprising a thin film of Teflon or Kynar sandwiched between layers of asphalt mastic. 

The simplest gas-solid containment systems conceptually are the direct adsorption ones. These accomplish adsorption on solids such as activated carbon, or alkalized alumina at relatively low temperatures and ordinary pressures [46]. In a separate unit a more concentrated sulfur dioxide stream is produced when the saturated absorbent is regenerated by heating. This is a more economically attractive feed to an acid plant or for liquefaction or sulfur generation. 

Phytanic acid a-hydroxylase. Phytanic acid accumulates in liver and kidneys, and it may represent over 50% of total liver fatty acids. Plasma phytanic acid concentrations of 200-3,100 mg/I have been repotted (normal <2 mg/1). Peripheral neuropathy and ataxia, retinitis pigmentosa and skin and bone abnormalities. TVeatment by plasma exchange and low phytol intake. [Phytanic acid is normally formed in the body from the plant alcohol, phytol, present as an ester in chlorophyll. Ihe presence of a branch methyl group at position 3 of phytanic acid means that the normal process of p-oxidation is blocked. Oxidation of fatty acids one carbon at a time (a-oxidation) is common in plants, but also occurs to some extent in animals, especially in the brain, where it serves to initiate degradation of phytanic acid. The resulting pristanic acid is then degraded by p-oxidation]... 

The acid gas produced contains more than 45 voI% hydrogen sulfide with the balance being carbon dioxide and a small amount of other impurities such as 0.1 vol% hydrogen cyaiude,. 01 vol% ammonia, and 1.1 vol% aromatics. Consequently, the acid gas is a suitable feed for a typical Claus unit. Operating problems such as plugging and corrosion associated with larger concentrations of these impurities are avoided. As an alternative, the acid gas is a suitable feed for a sulfuric acid plant... 

Opa.nte. There are two methods used at various plants in Russia for loparite concentrate processing (12). The chlorination technique is carried out using gaseous chlorine at 800°C in the presence of carbon. The volatile chlorides are then separated from the calcium—sodium—rare-earth fused chloride, and the resultant cake dissolved in water. Alternatively, sulfuric acid digestion may be carried out using 85% sulfuric acid at 150—200°C in the presence of ammonium sulfate. The ensuing product is leached with water, while the double sulfates of the rare earths remain in the residue. The titanium, tantalum, and niobium sulfates transfer into the solution. The residue is converted to rare-earth carbonate, and then dissolved into nitric acid. 

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