Calcium bisulfite

To an ether solution of 108 grams 1,4-benzoquinone, maintained below 0°C, one adds an also very cold solution of 102 grams of pure calcium bisulfite as a 50% solution in distilled water. The addition is made carefully so as to maintain a very low temperature (0° to 4°C) in the vessel, and under stirring so as to mix the water and ether phase. 

Cadmium chloride Naproxen Calcium bisulfite obesilate calcium Calcium carbonate Caraspirin calcium Medazepam Calcium chloride Docusate calcium Fibrinolysin Calcium ferricyanide Sulfamethizole Calcium hydroxide Cyclamate calcium Inositol... 

The catalytic hydrogenation of fatty oils, the desulfurization of liquid petroleum fractions by catalytic hydrogenation, Fischer-Tropsch-type synthesis in slurry reactors, and the manufacture of calcium bisulfite acid are familiar examples of this type of process, for which the term gas-liquid-particle process will be used in the following. 

The calcium bisulfite acid used in the manufacture of sulfite cellulose is the product of reaction between gaseous sulfur dioxide, liquid water, and limestone. The reaction is normally carried out in trickle-bed reactors by the so-called Jenssen tower operation (E3). The use of gas-liquid fluidized beds has been suggested for this purpose (V7). The process is an example of a noncatalytic process involving three phases. 

Kramfors A two-stage variation on the Sulfite papermaking process. The first stage uses slightly alkaline sodium sulfite the second uses acid calcium bisulfite. See also Stora. 

It combines with sulfur dioxide to form calcium sulfite hemihydrate, CaSOs MiH20 which can oxidize in air in the presence of moisture to give calcium sulfate dihydrate, CaS04 2H2O. However, when SO2 is passed through a solution of calcium hydroxide, calcium bisulfite, Ca(HS03)2 is obtained. The solution is yellowish when it contains bisulfite in aqueous SO2. 

Lignosite Lignosulfonate products are derived from the lignin in softwood trees by the calcium bisulfite pulping process at GeorgiarPacific s mill in Bellingham, Washington. 

Sulfite sodium sulfide Calcium bisulfite in None 40-50... 

For calcium-base liquor, the gas is passed through towers packed with limestone with water flowing down through the tower. Because of the limited solubility of calcium bisulfite [Ca(HS03)2], the pH of the liquor is very low (about 2), and free sulfurous acid is present. This usually is called the acid sulfite process. As mentioned before, calcium-base mills have essentially disappeared in the United States. 

Production of calcium acid sulfite (sulfur dioxide, water, and limestone) reacting to produce calcium bisulfite and used in the manufacture of sulfite cellulose 12, 31, 123,124... 

Sulfite process—process in which sulfur dioxide is passed through calcium carbonate to form calcium bisulfite in an excess of sulphurous acid as the cooking liquor. The wood pulp is then cooked under pressure at high temperatures. 

The basis of the sulfite pulping process is the discovery by Tilghman in 1866 that white cellulose fibers are obtained by cooking wood under pressure in an aqueous solution of calcium bisulfite Ca(HS03)2. In chemical terms, the process is founded on the fact that lignin, the solid binder of wood, reacts with sulfite to form water-soluble sulfonic acids. In this fash-... 

The controlling chemical reactions for the lime/limestone wet scrubbing SO2 removal systems have been established. In both the lime and limestone systems, the principal absorption reaction is calcium sulfite plus sulfur dioxide to form calcium bisulfite. Methods of preventing both calcium sulfite and calcium sulfate scaling are presented. 

Following the initial steps of hydration (Reaction 1) and formation of calcium sulfite (Reaction 2), removal of SO2 in the lime or calcium hydroxide system depends on the formation of calcium bisulfite by reaction of suspended calcium sulfite with sulfur dioxide and water (Reaction 3). 

The principal absorption reactions for the calcium carbonate system are shovm in Reactions 5, 6, and 7. Sulfur dioxide reacts with the relatively soluble bicarbonate to form calcium bisulfite. In addition, solid... 

Benzyl Octyl Adipate 3089-55-2 Butyl Acetate (sec-) 105-46-4 Calcium Bisulfite 13780-03-5... 

Since calcium sulfite is not very soluble in water, the last stage(s) of liquor preparation involve absorption of sulfur dioxide into the cold liquor under pressure. This eventually gives a ratio of about 1 mole of calcium hydrogen sulfite (calcium bisulfite) to a total of 4-5 mole of (sulfur dioxide + sulfurous acid). At this stage the pulping liquor is an aqueous solution, which contains 6.5-9% dissolved sulfur dioxide in all forms. 

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