Waste solvents

Definition

Source « Recycling and waste treatment in Picardy »Edition 2003 Ademe CR Picardy

A solvent is a liquid capable of dissolving another liquid, solid or gas. Solvents are used for cleaning and dilution mainly in industry (chemical manufacture, pharmacy, mechanics, printing, manufacture and use of rubber…).

They are also present, in dispersed quantities, in craft industries (body repairs, mechanics, glazers and varnishes, dry cleaning…), in research laboratories and teaching and even in households (cleaning products, stain removers…).

There are two categories of solvents :

• Halogen solvents which are essentially, chlorinated products (trichlorethylene, tetrachloroethylene, methane chloride…)

• Non-halogen solvents (toluene, acetone, white spirit, ethers…)

If disposed of in the natural environment, solvents can pollute the air, water and soil. The application of certain solvents is responsible for the formation of Volatile Organic Compounds (VOC) that contribute to the formation of photochemical oxidants such as ozone.

Figures

The annual production is around 600,000 tonnes but only 70,000 tonnes of solvents are collected and re-processed in collection centres (14 re-processing sites in France).

These tonnages do not include integrated re-processing carried out as an industrial process.

Regulation  

Treatment

Reduction : a reduction in quantities of solvents produced can be discerned, in particular in the field of paints and varnishes (manufacture, application), by developing solvent-free versions of these products: water-based paint, powder paints. Currently, there is a national movement to reduce quantities of solvents, in particular chlorinated solvents.

Collection and recycling : : Collection by the manufacturer is being developed increasingly; this is followed in many cases by transportation to recycling plants.

Suppliers (producer or distributor) displaying the “return” symbol granted by the ADEME (French Environment and Energy Management Agency), take back their customer’s used solvents (www.ademe.fr).

The service provided by the supplier to customers is :

• Return of all used products

• Appropriate organisation of waste collection, recycling or removal of used products

• Respect for environmental protection regulations

• Optimal economic conditions offered by the service

Solvent recycling , in particular chlorines is possible :

• Either on site, for companies producing high enough quantities

(installation of a facility for re-processing by distillation)

• Or by means of outsourcing companies who specialise in re-processing solvents

Re-processing is the most preferable technique for treatment.

Treatment : treatment of non-reprocessed solvents, as well as sludge and residue from re-processing facilities, must be carried out by incineration process (thermal treatment preferably with recycling of energy), in specialised facilities.

Incineration is the only solution for mixtures of used solvents of origin and nature that are too different. Certain cement manufacturers are authorised to accept these mixtures.HETS

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