Drums containing hazardous cleaning solvent waste are loaded onto a truck at the Kiilto factory. Their destination is not Fortum's disposal plant in Riihimäki, however — they are headed for the municipality of Marttila instead, where Arwina Oy's solvent refinery will process the waste and deliver the purified material back to Kiilto.
The Kiilto waste management team reviews the waste situation at the plant four times a year. The primary objective is to minimise waste production. Eco-friendly recycling and disposal options are sought for the waste that does get produced. Seven years ago, such options were explored for waste produced by cleaning solvents, and that is how Kiilto partnered up with Arwina.
A functional process that produces clean raw material
Cleaning the Kiilto glue reactors results in the production of 15,000 litres of cleaning solvent waste every year. Several solvent-free cleaning agents have been tested, but none produced the required results. Thanks to the co-operation between Arwina and Kiilto, the cleaning process has been made safe and the amount of hazardous waste has been minimised by the refinery’s distillation process. The first shipment of cleaning solvent waste from Kiilto to Arwina took place in 2010.
“Co-operation with Arwina has been fruitful and the process is effortless. We send our drums out to them twice a year. The distillation takes about two weeks, after which Arwina sends back clean solvent that we can use again, and they also send a report of the distillation results. The final yield of clean solvent depends on many factors, for example the initial purity and composition of the waste”, says Sirpa Koukkula, product development co-ordinator and chairperson of the waste management team at Kiilto, describing their process.
Nearly all acetone can be recycled
Before Arwina, Kiilto used to ship the waste to Fortum (formerly Ekokem). Now, most of the waste can be purified and used again as a cleaning agent. According to Arwina, most of the recovered solvent waste can be purified and reused.
“We have worked with Kiilto to improve the efficiency of the distillation process by mixing the acetone being distilled with a non-distillable solution. This improves the yield considerably: more than 90% of the acetone can be recovered and reused”, says Esko Pietilä of Arwina Oy.
“This distillation of cleaning solvents saves us money and reduces our use of pure raw materials, as well as cutting down on the amount of waste we produce”, Koukkula sums up.
Industrial symbiosis promotes the circular economy
Arwina Oy was awarded the pro-environment Ympäristöteko commendation in 2016. The commendation is awarded to a company with an advanced process of industrial symbiosis in place.
“Our symbiosis is a positive and functional example of the circular economy in practice. Companies should consider how they can implement circular economy principles in their operations by creating industrial co-operation networks. Even small solutions can bring change and result in wider applications”, urge Sirpa Koukkula and Esko Pietilä.