Sodium perborate production

Precipitate formation can occur upon contact of iajection water ions and counterions ia formation fluids. Soflds initially preseat ia the iajectioa fluid, bacterial corrosioa products, and corrosion products from metal surfaces ia the iajectioa system can all reduce near-weUbore permeability. Injectivity may also be reduced by bacterial slime that can grow on polymer deposits left ia the wellbore and adjacent rock. Strong oxidising agents such as hydrogen peroxide, sodium perborate, and occasionally sodium hypochlorite can be used to remove these bacterial deposits (16—18). 

Industry sources indicate worldwide production of hydrogen peroxide and sodium perborate mono- and tetrahydrate, which are used almost exclusively for bleach appHcations, is 1.1 x 10 t per year and 6.4 x 10 t per year, respectively, in 1990. 

Sodium Perborate Hydrates. Peroxyborates are commonly known as perborates, written as if the perborate anion were BO . X-ray crystal stmcture has shown that they contain the dimeric anion [(H0)2B(02)2B(0H)2] (7) (92). Three sodium perborate hydrates, NaBO XH2O (x = 1, 3, and 4), are known. Only the mono- and tetrahydrate are of commercial importance, primarily as bleaching agents (qv) in laundry products. 

In 1986, Turkey produced nearly one million metric tons of mineral concentrate, whereas production of refined borate chemicals was 89,500 metric tons. Annual production capacities of chemicals at Eskiseher were pentahydrate borax, 160,000 t anhydrous borax, 60,000 t and decahydrate borax, 17,000 t. Capacities at Bandermes were decahydrate borax, 55,000 t boric acid, 33,000 t and sodium perborate, 64,000 t (103). 

There are two U.S. producers of sodium perborate. E. I. du Pont de Nemours Co., Inc., in Memphis, Tennessee has converted part of their tetrahydrate capacity into monohydrate production (109). Interox has a monohydrate plant with a capacity of 20,000 t in Deer Park, Texas (109,110). 1991 U.S. consumption of sodium perborate was about 27,000 t, compared with about 45,000 t in the mid-1970s. 

In a 1-1. three-necked round-bottomed flask equipped with an eflicient stirrer, a reflux condenser, and a thermometer (Note 1) are placed 500 ml. of glacial acetic acid (Note 2), 29.0 g. (0.19 mole) of -aminoacetanilide (Note 3), 40 g. (0.26 mole) of sodium perborate tetrahydrate, and 10 g. (0.16 mole) of boric acid. The mixture is heated with stirring to 50-60° and held at this temperature for 6 hours. Initially the solids dissolve but, after heating for approximately 40 minutes, the product begins to separate. At the end of the reaction period, the mixture is cooled to room temperature and the yellow product is collected on a Buchner funnel. It is washed with water until the washings are neutral to pH paper (Note 4) and then dried in an oven at 110°. The yield of 4,4 -bis(acetamido)a2obenzene, m.p. 288-293° (dec.), is 16.5 g. (57.7%). It is used as such for the hydrolysis step (Note 5). 

Many metal borates find important industrial applications (p. 140) and annual world production exceeds 2.9 million tonnes Turkey 1.2, USA 1.1, Argentina 0.26, the former Soviet Union 0.18, Chile 0.13Mt. Main uses are in glass-fibre and cellular insulation, the manufacture of borosilicate glasses and enamels, and as fire retardants. Sodium perborate (for detergents) is manufactured on a 550 000 tonne pa scale. 

World production expressed as 100% H2O2 approached 1.9 million tonnes in 1994 of which half was in Europe and one-fifth in the USA. The earliest and still the largest industrial use for H2O2 is as a bleach for textiles, paper pulp, straw, leather, oils and fats, etc. Domestic use as a hair bleach and a mild disinfectant has diminished somewhat. Hydrogen peroxide is also extensively used to manufacture chemicals, notably sodium perborate (p. 206) and percarbonate, which are major constituents of most domestic detergents at least in the UK and Europe. Normal formulations include 15-25% of such peroxoacid salts, though the practice is much less widespread in the USA, and the concentrations, when included at all, are usually less than 10%. 

As recommended laundering temperatures have tended to fall in recent years, a bleach consisting of sodium perborate activated by addition of tetra-acetylethylenediamine (4.110 TAED) has become an important component of household detergent formulations. This system is effective at temperatures as low as 40-50 °C. A recent study of the effects of TAED-activated peroxy bleaching on the colour fastness of azoic dyeings has demonstrated that the sensitivity of these products can be related to their chemical structure. Electron-donating substituents in the diazo component enhance resistance to oxidative attack under these conditions, as do the size and complexity of substituents present in the coupling component [110]. 

This is an alternative method of introducing copper into an o-hydroxyazo dye structure. The azo compound is treated with a copper(II) salt and an oxidant in an aqueous medium at 40-70 °C and pH 4.5-7.0. Sodium peroxide, sodium perborate, hydrogen peroxide or other salts of peroxy acids may be used as oxidants, the function of which is to introduce a second hydroxy group in the o -position [25]. This process is reminiscent of earlier work on Cl Acid Red 14 (5.51 X = H), an o-hydroxyazo dye that will not react with a chromium (III) salt to form a 1 1 complex but will do so by oxidation with an acidified dichromate solution. This oxidation product was later found to be identical with that obtained by conventional reaction of Cl Mordant Black 3 (5.51 X = OH) with a chromium(III) salt [7]. 

Experimental Materials. Sodium perborate tetrahydrate (NaB02 4H20) was obtained from Alfa Products titration for available H2O2 by KMnO gave > 95% of theoretical equivalency. 

Figure 1. Pseudo-first-order kinetic plot of - n(A -Ao)/ A -Ag) versus time for production of p-nitrophenolate from reaction of sodium perborate at various concentrations with EPMP at 27.5 oc, pH = 8.

A 500-ml three-necked flask was charged with 2,7-dibromo-9-fluorenone (6.65 g), 140 ml trifluoroacetic acid/chloroform, 1 1, and sodium perborate monohydrate and then stirred for 20 hours. The reaction liquid was filtrated through Celite and then washed with toluene. The filtrate was washed with water, sodium hydrogen sulfite, and saturated saline and then dried over Na2SC>4. After concentration 6.11 g of residue was obtained. After recrystallization from chloroform 1.19 g of product was isolated. 

The same products are formed with sodium perborate, a cheap industrial chemical when used in Ac20 + H2S04.484... 

Many heterocyclic bases can be oxidized to A-oxides with sodium perborate and acetic acid in the absence of metal catalysts.352 Use of a smaller excess of oxidant leads to diazo compounds.353 Aliphatic amines can be converted to nitroso products. Sodium perborate/acetic acid systems can also cleave hydra-zones, regenerating carbonyl compounds which have been protected by hydrazine formation.354... 

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