Sodium carbonate solutions hydrogen sulfide removal with

A colorless solution is obtained from which the tin is removed by precipitation with hydrogen sulfide. On addition of sodium carbonate solution, 3-Amino-4-propoxybenzoic acid 2-(diethylamino)ethyl ester separates as an oil. When treated with one equivalent of hydrochloric acid it forms a hydrochloride, which is readily soluble in water and crystallizes from a mixture of absolute alcohol and ethyl acetate in white prisms MP 182.0-183.3°C. 

Potassium Permanganate. Probably the most widely used process for removing traces of hydrogen sulfide from carbon dioxide is to scmb the gas with an aqueous solution saturated with potassium permanganate [7722-64-7]. Sodium carbonate is added to the solution as buffer. The reaction is as foUows ... 

Sodium and Potassium Hydroxides. Sodium hydroxide [1310-73-2] and potassium hydroxide [1310-58-3] (Class 1, nonregenerative) are commonly used when moisture and carbon dioxide or hydrogen sulfide must be removed simultaneously (4). Fused sticks or solutions of the alkah hydroxides are frequentiy used. These materials must be handled with care to prevent serious skin bums. 

Samples are hydrolyzed with hydrochloric acid and stannous chloride solution at elevated temperature, and the evolved carbon disulfide is drawn with an air steam through two gas washing tubes in series containing lead acetate and sodium hydroxide solutions and an absorption tube containing an ethanolic solution of cupric acetate and diethanolamine. Lead acetate and sodium hydroxide remove hydrogen sulfide and other impurities. In the absorption tube, the carbon disulfide forms two cupric complexes of Af,Af-bis(2-hydroxyethyl)dithiocarbamic acid with molecular ratios Cu CS2 of 1 1 and 1 2. These complexes are measured simultaneously by spectrophotometry at 453 nm. 

Sodium Salt (54)3717a,20 20,21-Bismethylenedioxy-1, 2 -dihydroxypregn-4-ene-3, l-dione (53).37 A solution of 100 g of 17a,20 20,21-bismethylene-dioxypregna-l,4-diene-3,ll-dione (prednisone BMD) (52) in 720 ml of pyridine is cooled to 5° and treated with a solution of 69.9 g of osmium tetroxide in 408 ml of pyridine. The mixture, which turns black within 5 min is allowed to stand at room temperature for five days and then is added with stirring to 13.4 liters of petroleum ether. The crude osmate ester is isolated by filtration and washed with petroleum ether to remove most of the residual pyridine. The crude product is dissolved in 8 liters of dioxane and kept in an ice bath while a slow stream of hydrogen sulfide is bubbled through the reaction mixture. The precipitated osmium sulfide is removed by filtration, and the filtrate is concentrated to dryness in vacuo. The residual foam is dissolved in 2 liters of acetone, decolorized with activated carbon, filtered and concentrated to a volume of 1 liter. Addition of 1 liter of Skellysolve B affords 38 g of diol (53) A OH 236 mfi (e 14,100). 

To produce sodium chloride from brine, water is pumped into the salt deposit and the saturated salt solution containing 26% salt, 73.5% water, and 0.5% impurities, is removed. Hydrogen sulfide is removed by aeration and oxidation with chlorine. Calcium (Ca2+), magnesium (Mg2+), and iron (Fe3+) are precipitated as the carbonates using soda ash and are removed in a settling tank. The brine solution can be sold directly or it can be evaporated to give salt of 99.8% purity. 

The HTS catalysts are typically produced by precipitation of aqueous solution of iron sulfate and chromium sulfate with sodium carbonate or sodium hydroxide, followed by careful washing to remove essentially all of the residual sulfate. Washing is an important step in the catalyst manufacture, since the residual sulfate converts into hydrogen sulfide when the catalyst is reduced during the process startup, and hydrogen sulfide is a poison to the LTS catalyst located downstream of the HTS bed.t l... 

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