Sodium carbonate peroxyhydrate - commonly refered to as sodium percarbonate - is an addition compound of sodium carbonate and hydrogen peroxide.

OXYPER® S,  Solvay coated and stabilised sodium carbonate peroxyhydrate (or sodium percarbonate) combines the dual properties of sodium carbonate and hydrogen peroxide, to provide significant benefits in detergent applications.

The combination of 'two functions in one' product, in addition to a high available oxygen content and high bulk density,  allows OXYPER® S to improve detergency performance  while reducing the need for additional builders and consequently the environmental impact of the formulated detergents.

OXYPER® Sodium carbonate peroxyhydrate has minimal impact on the environment, decomposing after use into water, oxygen and soda ash.

The dual properties of sodium carbonate and hydrogen peroxide can also provide provide significant benefits to the user in environmental applications as a solid easy to use source of alkaline hydrogen peroxide.

OXYPER^R sodium carbonate peroxyhydrate grades have the following general properties:

OXYPER® S, sodium carbonate peroxyhydrate, is an oxidising agent which can be decomposed by water, direct sources of heat, catalysts etc. Decomposition is accompanied by the liberation of oxygen and steam which can support combustion and cause pressure bursts in confined spaces. Decomposition in the presence of organic material can be rapid and highly exothermic.

We recommend the following general guidelines for storage of sodium carbonate peroxyhydrate:

• Store at <40oC in a dry area.
• Protect from direct sunlight.
• Keep away from heat sources.
• Avoid contamination by moisture, dirt or other chemicals.
• Keep away from organic material, acids, alkalis, reducing agents and metallic contamination.

Contact your local Solvay Office for further information.

OXYPER® sodium carbonate peroxyhydrate is available both in 25 kg and in I tonne bulk bags.

For larger applications, OXYPER® products can be delivered in bulk.

Please contact your local Solvay Office for further information.

OXYPER® products (UN 1479) are oxidisers in category 5.1 of the ADR (road), RID (rail), IMDG (sea) and IATA (air) transport regulations.

The transport of sodium carbonate peroxyhydrate may be subject to special restrictions in certain countires.

Road transport must always be covered by a transport safety sheet (TREMCARD).

When handling OXYPER® S products always wear gloves, dust mask and goggles. Practice good industrial hygiene. Only use equipment made of suitable materials, e.g. plastic, stoneware, glass, stainless steel (e.g. 316L) and avoid the use of incompatible materials.

For more detailed information please refer to the Material Safety Data Sheet. Further information on the handling of sodium carbonate peroxyhydrate is available from your local Solvay office.

If you require any information in the event of an emergency involving sodium carbonate peroxyhydrate please call the number shown.

Information will be provided on topics such as product identification, properties, hazards and actions to take in the event of fires, major spills etc.

CALL: 00 - 49 - 89 45 56 03 21

The phoneline will operate anywhere in eastern or western Europe and in all local languages.

Important : this is an emergency telephone line and must not be used for non-emergency calls.

  
  In domestic laundry, 
  industrial laundry and 
  dishwashing processes a
  bleach is normally added to
  aid the removal of
  'bleachable' stains, such as
  those associated with
  polyphenolic molecules
  derived from tea, coffee, red wine, fruit juices etc. This bleaching step involves the chemical destruction of the chromophore in the stain, and also helps to remove the stain molecule from the surface by increasing the solubility of the oxidised stain molecule.

Unlike traditional bleaches which can cause damage to both dyes and fibres, and which need to be added seperately due to poor compatibility with other formulations ingredients, the use of persalt based bleach systems enable a wide range of complete formulations to be produced. The use of persalts in formulated detergent powders, in dishwash powders and tablets, and in bleach additive products present the formulator with a number of options for incorporation of an effective bleach system for washing under all conditions.

Bleaching of oxidisable stains by persalt products is enhanced by increasing temperature, the concentration of hydrogen peroxide, the length of time taken for the wash and the pH. Persalts dissolve in water to provide an alkaline solution of hydrogen peroxide, with a natural pH of 10 - 10.5, maximising the level of the perhydroxyl anion, the active species available for bleaching, and are ideal for providing a bleaching effect on a wide range of bleachable stains.

The bleach performance can be enhanced at low temperatures by the inclusion of peroxygen bleach activators into formulations. The most widely used is the activator Tetra Acetyl Ethylene Diamine (TAED), which reacts with the hydrogen peroxide present in solution to produce peracetic acid and the peracetate anion in situ.

The use of persalt products with TAED gives a rapid generation of peracetic acid over a wide temperature range, which improves the bleaching of stains at cold to medium wash temperatures (30 - 500C). A sufficient molar ratio of Persalt : TAED is required for efficient generation of peracetic acid, and to maintain bleach performance for both medium and high temperature washing.

In addition to enhancing the stain removal the presence of peracetic acid provides an enhanced biocidal activity which can reduce the level of bacteria remaining on clothes and surfaces.

  
  Detergent products are
  formulated with a range of
  materials all required to
  deliver specific cleaning
  performance. Such
  formulations contain
  surfactants, builders, sequestrants, perfumes, corrosion inhibitors, enzymes, optical brighteners and bleaches.The major use worldwide for solid forms of hydrogen peroxide, is as bleaching agents in domestic laundry powders.

For many years sodium perborate tetrahydrate was the standard bleaching agent in laundry detergent powders, with sodium perborate monohydrate used in markets with low washing temperatures. In recent years detergent powders have undergone many changes in formulation, with the aim of improving cleaning performance and reducing the impact of cleaning products on the environment. This has lead to the introduction of more compact detergent formulations and the introduction of detergent tablets, based on new raw material technologies.

The introduction of these new formulations has resulted in a reduction of the chemical dosages used in the wash, and to a reduction in packaging waste. The growth of these formulations has also lead to an increase in the use of sodium carbonate peroxyhydrate in fully formulated detergent products.

OXYPERR S products have a high available oxygen content and high bulk density, ideal for use in detergent powder and tablet formulations, and provide both bleach and builder functions.

Because detergent formulations vary from country to country, based on factors such as water hardness, legislation and consumer preferences, Solvay provides formulators with technical support to ensure that their persalt based formulations produce optimum performance.

  Peroxygen bleaches based on
  Solvay persalt products offer many
  benefits to industry. Unlike
  traditional products that require a
  separate bleach cycle, persalt based
  bleaches are used with detergent in
  the break suds cycle, where higher
  alkalinity and higher water
  temperatures enhance the bleaching
  and cleaning power.

Eliminating the need for a separate bleach cycle removes the need for subsequent rinses and an antichlor stage. This reduces processing time and thus increases throughput capacity. The economy of the commercial laundry process can be further improved with the resulting savings in chemical, water and energy costs.

While traditional bleaches can destroy dyes and finishes in some synthetic fabrics, persalt based oxygen bleaches are safely used on most washable fabrics. Also, bleaching systems based on persalts cause less fibre damage than chlorine based products, and can help to extend fabric life, reducing replacement costs.

 
  Laundry additive products
  containing a bleaching agent
  are used in domestic
  laundering to improve stain
  removal and maintain fabric
  brightness. These products
  are generally formulated with
  persalts.

Many dry bleach products are based on OXYPER®S, sodium carbonate peroxyhydrate, due to its rapid dissolution in low temperature wash liquors, although sodium perborate products can also be used. Persalt based dry bleaches can be used as additives to the wash cycle or used for pre-soaking of stained fabrics, prior to washing.

Persalts can be used as stand alone bleaches, or formulated with other ingredients, including a bleach activator, fluorescent whitening agents and enzymes.

For medium to high temperature washing, products containing only persalts provide effective stain removal. persalt based products also give effective stain removal at cold temperatures (20oC) when used in soak and pre-soak products. In addition to the bleaching of stains, persalt based formulations will help remove odours, protect colours by the removal of chlorine from the water, and provide a bactericidal effect.

  A typical automatic dishwashing
  formulation has to meet several
  basic requirements. It must
  remove soil, control foaming,
  inhibit corrosion, and prevent
  precipitation of water hardness
  ions to reduce spotting and
  streaking. The challenge to
  formulators is to find the
  combination of ingredients that
provides good performance, whilst improving safety to the consumer and the environment.

Persalts products offer several benefits. They include good compatibility with other ingredients, the ability to reduce alkalinity, reduced glass etching and metal corrosion, and low environmental impact. The replacement of chlorinated compounds with persalts in dishwashing formulations has allowed other changes in the formulation to deliver more effective cleaning performance.

Dishwashing temperatures are high enough for good stain removal performance. If required, organic activators, such as TAED, can be added to increase the bleaching performance of persalts at lower temperatures. This can also provide an additional benefit in enhancing the bactericidal activity of the product.

The use of persalts allows formulators to use enzymes for the removal of starch and protein soils, reducing spotting and improving overall cleaning. Enzymes can also compensate for the loss of detergent efficacy when less aggressive chemicals are incorporated in the formulation. Sequestering agents can further reduce spotting by controlling water hardness and preventing protein redeposition.

In addition, persalts allow formulators to use more cost effective surfactants and perfumes due to improved compatibility between formulation ingredients.

  Many applications require the use
  of either hydrogen peroxide or
  oxygen to solve environmental
  problems. Hydrogen peroxide
  can act as a chemical oxidant and
  reductant, as a supplier of
  molecular oxygen and can be
  applied to inhibit undesirable 
microbial growth. However for applications where the use of liquid hydrogen peroxide is impractical, then OXYPER® S products offer the power of hydrogen peroxide in a convenient solid form. 

OXYPER® S products contain an equivalent available peroxygen content to ca. 28% hydrogen peroxide, combined with sodium carbonate as a source of alkalinity. They decompose to leave only water, oxygen and soda ash.

Therefore, OXYPER® S products are a very easy to use source of hydrogen peroxide for environmental control.

Peroxygens are widely used throughout industry for the safe and effective treatment of cyanide in process and waste waters. Under alkaline conditions cyanide is efficiently oxidised to the, much less toxic, cyanate by peroxygens such as hydrogen peroxide, Caro’s acid and sodium percarbonate. For example with hydrogen peroxide :-

CN- + H2O2 --> CNO- + H2O

The cyanate formed during oxidation of cyanide undergoes hydrolysis to carbonate and ammonia.

Peroxygen treated waste waters can usually be safely discharged following ammonia removal if necessary eg. via ammonia recovery or biological nitrification.

OXYPER® S, sodium carbonate peroxyhydrate, is particularly useful for emergency treatments eg. for spillages to natural waters, when solid oxidants can provide storage and handling advantages over liquid alternatives. Solvay supplies the OXYPER® S grades of sodium carbonate peroxyhydrate as granular solids which dissolve quickly in water to yield an alkaline solution of hydrogen peroxide and sodium carbonate.

For treatment of concentrated cyanide waste and process waters, hydrogen peroxide is a very efficient oxidant - reducing cyanide levels from several thousands of ppm to below 1 ppm. The rate of cyanide removal with hydrogen peoxide varies from hours down to minutes depending on the nature of the cyanide (whether complexed or free), the treatment conditions (pH and temperature) and the presence of other components in the waste water. In most cases, reaction rates and the extent of cyanide removal can be enhanced by addition of soluble metal catalysts eg. copper.

The use of sodium carbonate peroxyhydrate for cyanide destruction provide a source of alkali from the soda ash which helps to maintain a high pH and to prevent emission of toxic hydrogen cyanide during treatment. 

Environmental authorities are increasingly requiring dechlorination of waste streams: the upper limits for chlorine content may be as low as parts-per-billion.

Hydrogen peroxide offers many benefits as a dechlorination agent. Under optimum conditions the reaction occurs instantaneously and removes chlorine concentrations in the range from parts-per -billion up to several percent. When the pH is above 8.5, hydrogen peroxide reduces hypochlorite to chloride ions, producing oxygen as a byproduct.

OCl- + H2O2 --> Cl- + H2O + O2

OXYPER® S,sodium carbonate peroxyhydrate, products offer the advantages of hydrogen peroxide in an easy-to-use solid form, providing both the alkalinity and the hydrogen peroxide for instantaneous and quantitative chlorine removal.

Reduced sulphur compounds plague many industrial and municipal facilities, e.g. refineries, chemical plants, tanneries, pulp/paper mills and waste water treatment plants. Reduced sulphur compounds such as hydrogen sulphide can cause serious problems to plant and personnel through formation of noxious odours, poisonous and flammable atmospheres, and corrosion of equipment. Treatment with hydrogen peroxide provides a cost effective and highly efficient, means of removing these compounds from both gaseous and aqueous waste streams.

OXYPER® S, sodium carbonate peroxyhydrate, is used as a solid source of hydrogen peroxide in order to raise reduced sulphur species to higher oxidation states. The use of OXYPER® S products transforms sulphide into sulphate at alkaline pH,:

S2- + 4H2O2 --> SO42- + 4H2O

OXYPER® S products can also be used to convert sulphite to sulphate, and thiols (or mercaptans) to sulphonates. The use of the hydrogen peroxide released from OXYPER® S products decreases the toxic and corrosive nature of the species whilst also lowering the chemical oxygen demand (COD) of the waste stream.

OXYPER® S products can also be used as a preventative measure. As an oxygen supplier, the hydrogen peroxide released helps to maintain aerobic conditions in waste wasters and prevents the production of reduced sulphur species by anaerobic micro-organisms.

Hydrogen peroxide, as a supplier of molecular oxygen in-situ, can be used as a supplementary oxygen source to prevent or cure biological upsets under low dissolved oxygen conditions. Sodium carbonate peroxyhydrate is best used as an emergency treatment where a rapid easy to handle source of dissolved oxygen is required.

OXYPER® S products can also help to enhance the dissolved oxygen content at the bottom of lakes and rivers due to the tendency of the product to sink to the bottom before complete dissolution occurs.

THe hydrogen peroxide released breaks down on contact with biological material to yield oxygen according to the formula:

2H2O2 --> 2H2O + O2

2.13 ppm of hydrogen peroxide (100%) is equivalent to 1ppm of O2 supplied. Sodium carbonate peroxyhydrate is equivalent to ca. 28% Hydrogen peroxide and therefore  7.3 mg of OXYPER® S product is required per mg of dissolved O2.The oxygen gas bubbles formed from the decomposition of the hydrogen peroxide are extremely small, allowing fast dissolution to dissolved oxygen.

Oxidative pre-treatment of industrial effluents with hydrogen peroxide can reduce toxicity and chemical oxygen demand (COD) thereby improving the biodegradability of the waste water. OXYPER® S sodium carbonate peroxyhydrate is an effective solid carrier for hydrogen peroxide which is easy to store and handle and therefore ideal for use in case of emergencies.

Hydrogen peroxide reacts directly with many commonly occurring inorganic pollutants for example - chlorine, cyanide, formaldehyde, sulphide, sulphite and thiosulphate. In many cases the additional alkali present from the soda ash in OXYPER® S products helps with the rapid destruction of the pollutant. Such pollutants are oxidised to less noxious products thus reducing their contribution to the oxygen demand of the effluent and often resulting in control of noxious odours.

Hydrogen peroxide treatments are best applied at the pollutant source. Treating the pollutant when it is at its highest strength in the waste water reduces the consumption of hydrogen peroxide.

TABLE : PEROXYGEN TREATMENTS AND PRODUCTS OF TREATMENT FOR COMMONLY OCCURRING WASTE WATER POLLUTANTS

  
 
   Persalts can be used in 
   textile applications as a 
   solid alternative to
   hydrogen peroxide. They  
   can be used as the bleaching agent to improve fabric whiteness or in the dyeing process for the fixation of VAT and sulphur dyes.

Dye Oxydation

The process of dyeing cotton textiles with insoluble VAT or sulphur dyes requires the use of a reducing agent to solubile the dye into the fabric. This is followed by the use of an oxidant to fix the dye onto the fibre and provide a colour fast finish.

Persalts are used as a convenient way of adding hydrogen peroxide to dye oxidation baths in order to fix the dye onto the fabric.

Hydrogen peroxide and caustic soda are commonly used for the bleaching of a range of textile materials in order to improve fabric whiteness.

Persalts, which provide a source of hydrogen peroxide and alkalinity, can be used when a solid bleaching agent is preferred. They can also be used as a simple additive to improve some scouring processes.