PRE-TREATMENT , SURFACE PREPARATION , DEGREASING & CLEANING
Solvents are unsustainable ? Not when you consider these 4 environmental aspects
The word solvent still conjures up negative associations for many people , especially when it comes to aspects such as safety , environmental impact and in particular – sustainability . A closer look into the technical , economic and ecological factors will reveal that such biased perceptions are in fact unsubstantiated .
Nowadays , solvents meet strictest environmental standards and Registration , Evaluation , Authorization and Restriction of Chemicals ( REACH ) requirements . At the same time , great technological advances in solvent cleaning systems are leading to environmentally sound and responsible cleaning options .
To evaluate solvent use through the lens of sustainability , the performance of the solvent itself is just as crucial as the process and system within which it is used . Taking into account energy usage , solvent recyclability , waste treatment and disposal , as well as chemical impact on the environment , solvents when used in combination with modern closed cleaning machines , may even have a better environmental profile than many other cleaning methods .
When used in combination with closed cleaning machines , solvents provide 4 distinct benefits that contribute to sustainability :
1 . Virtually no air emissions 2 . Miniscule solvent consumption and long bath life 3 . Low waste volume 4 . Low energy usage
1 . Virtually no air emissions when used in modern sealed plants
Solvent losses into the air from open top machines used to represent a major portion of organic pollution . However , modern closed cleaning machines running in vacuum conditions 1 – for both chlorinated and non-halogenated solvents – means that there is virtually no emission in the cleaning process .
In addition , the application can be fully bundled with closed loop solvent delivery systems which can prevent emission during transfer and handling of solvents from and into the machine .
The graphic here shows the amount of solvent required to remove 100kg of oil , and the corresponding losses due to air emissions and solvent in waste streams , when different machine technology is applied .
54 MARCH 2021
Source : Chemical product services in the European Union , European Commission , January 2006
The deployment of a closed cleaning machine can already dramatically reduce the amount of solvent used by almost 5 times , from 745kg to 160kg . With the support of Chemical Product Services ( CPS ), such as consistent solvent monitoring and stabilization , along with the SAFE-TAINER™ System for the safe transport , handling and storage of both fresh and used solvents , the amount of solvent required can be further reduced by over 90 %, dropping from 160kg to a mere 15kg . Process optimization can bring down solvent consumption further still .
Both emissions and wastage volumes also drop significantly , while user safety standard and environmental protection are heightened at the same time .
2 . Minuscule solvent consumption and long bath life
In modern , closed cleaning machine , used solvent can be constantly re-purified and nearly completely recycled in the distillation unit . This routine recycling means there is very low solvent replacement volumes necessary . It also reduces health and safety risk , and brings in cost savings not only in terms of solvent consumption , but also time , labor and paperwork due to minimal wastage .
Nevertheless , since more work demand is made on less solvent input , the stress on solvents could increase . Regular monitoring and maintenance of the solvents can therefore help extend solvent lifespan , and in return , the bath life cycle .
3 . Low waste volume
Since solvents can be effectively recycled and reused following distillation , the waste volumes are much lower . Compared to aqueous cleaning , solvents can be easily separated from oils by distillation . The higher the temperature difference between solvent and oils in their boiling points , the better the separation by distillation .
CONTINUED ON PAGE 56
twitter : @ surfaceworldmag