October 28, 2022: Italian lead recycler and engineering company STC said on October 20 that the installation of a new energy recovery system at a lead recycling plant operated by its parent company, Monbat, is currently saving the firm around 1.8 million m3 of natural gas annually.
Following the success of the mechanical vapour recompression (MVR) system at Monbat’s recycling facility in Serbia, the European lead battery giant now plans to install MVR systems at its lead battery recycling plants in Bulgaria and Romania — which are eventually expected to achieve combined gas savings of around 5 million m3 every year.
An STC spokesperson told BESB the MVR collects pure water vapor arising from the evaporation of the sodium sulphate solution, which contains no noxious substances.
The system is used to produce heat that can be used in the crystallization of the sodium sulphate solution, which is a by-product of the lead paste desulphurization reaction.
Before the installation of the MVR, the crystallizer was “a direct live steam crystallizer”, where the steam from an existing gas steam boiler was used to heat up and evaporate the sodium sulphate solution, the spokesperson said.
“The MVR is more in line with circular economy principles, because it recycles the steam coming from the crystallizer through an electrically driven mechanical recompression — without the need to add steam from the gas boiler, which remains only as back-up. This leads to both economical savings and to the tangible support of environmental sustainability.”
Following its initial success at Monbat, the system could be offered to other companies, the spokesperson said, adding that the processing of desulphurized paste provides significant advantages to lead acid batteries recyclers.
STC said it is able to provide different desulphurization processes — “traditional” with soda ash or caustic soda or its patented U4Lead that uses urea as chemical and produces ammonium sulphate as a by-product.
BESB reported last May that STC had been awarded a $5 million contract to supply a lead battery recycling plant to Tunisian battery maker Nour, in which Monbat owns a 60% stake.