Waste treated with quicklime to avoid incineration

29 Juin 2005

The French Group OXALOR proposes a recycling technology of waste by means of dehydration based on quicklime.  The overall treatment process requires no grinding nor incineration.  On top of re-use based on selective sorting, a fertilizer of exceptional quality is obtained…In the OXALOR factory, it is difficult to believe that household waste is being treated.  Except for the noise, everything is clean and without odour. The machines seem robust…and they are each part of the Oxalor process which is a patented technology…

The history of the technology started in 1996 with an idea to mix waste to a natural reagent based on Calcium Oxide (commonly known as quicklime) mixed with water….The mixture procures an exothermic reaction between 75 and 90° thus dehydrating and sanitizing the household waste… Adding lime creates an ultra basic medium (pH 12.8) allowing the stabilization of the organic matter and facilitating downstream sorting…On top of this, the dehydration improves the calorific value of plastic waste which are similar to those of natural gas or methanol….for exemple used in cement plants as a substitute for traditional fossil fuels… Transformed into fragments of 8 to 10 cm diameter, the stabilized waste flux goes through a number of sieves and separators thus separating the organic matter from the inorganic matter.  At the end of the chain, conveyor belts allow further separation of plastic, glass, plastic,…

Industrial ecology

The fermentable fraction of the waste is transformed into a fine greyish powder : an organo-calcic amendment, Sold at 10 EUR/T, this amendment (a sort of organic fertilizer) contains 33 to 38% of agricultural lime and allows to change soil acidity.  Studies realized with a view of obtaining its homologation have confirmed that the product is safe and efficient in terms of its agricultural qualities.

The Oxalor method is flexible, simple, compact, quick and inexpensive.  Two hours ½ are needed to tranform waste into a final stabilized product .  Compared to incineration and methanization, OXALOR is very economical, and not at all energy-intensive, short storage time, reduced water consumption which is recuperated after its evaporation and re-injected in the process….

Charged with the treatement of sludge sewage from Niort and household waste from the « Community of Communes » of Lezay, the plant remains modest and is a showcase destined to show the efficiency of the technology.  The capacity of the lant is only at 9T/day, just over 3,000T/year.  A second plant for the treatment of 60,000 T is foreseen for the end of 2006 and will be used for the treatment of household waste only – amount of investment : 9.8 Million EUR, the first factory in France …

Maxence LAYE

Novethic.fr