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Pure & sustainable: High-end circular solvents
Stuart Barker of Indaver Solvents explains how recycled solvents provide high-quality materials as part of a carbon-positive circular economy
The term ' solvent ' is applied to a large number of chemical products that are used to dissolve or dilute other substances or materials. Many solvents are used as chemical intermediates, fuels and components of a wide range of products.
In fact, it seems fair to say that industrial solvents are somewhat ubiquitous, being used in the manufacture of a vast range of products, from pharmaceuticals and agrochemicals to batteries, microelectronics, the automotive industry and more. Solvents are usually organic liquids, although industrial solvents are often mixtures of several individual substances, and they can be found under a variety of trade names.
Disposal risks
Most leftover or used solvents are considered hazardous materials, and their improper disposal can lead to significant environmental contamination, including soil and water pollution, air pollution from volatile organic compounds( VOCs) and potential health risks to humans and wildlife.
As a result, the disposal of used solvents has become increasingly regulated, and failing to comply with disposal regulations can come at a very large cost. In the UK, fines for the illegal storage of hazardous materials such as used solvents has seen companies fined £ 1 million or more.
Fortunately, most current-day companies dispose of their leftover
Distillation column
Boiler
Fractionating column
Pressure swing plant
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or used solvents properly and responsibly. This is a good outcome, but proper disposal of hazardous materials is expensive, and companies find themselves in a constant cycle of buying and transporting new solvents, just to use them, dispose of them, and then buy more new ones again. Surely, in our modern world of technological advances, there must be a better, more efficient and sustainable way.
Sustainable solutions
In fact, solvents lend themselves well to a circular economy. Solvent recovery processes extract pre-used solvents from industrial streams, so they can be used again- and again, and again.
Using current technologies, companies can typically expect to recover up to 95 % of used solvents, even from more complex mixtures. It is possible to recover and recycle
Suitable for products requiring high-purity extraction
Suitable for high percentage specification products( e. g. 99.9 % purity)
Bespoke technology for breaking azeotropic compounds
High quality, pure, recovered solvent
Low grade solvents( not suitable for recovery)
Figure 1 – Recovering solvents thorough multi-stage fractionation
industrial solvents with the purity and quality of new virgin materials. In fact, in terms of quality and purity, most recovered solvents are indistinguishable from virgin solvents and they can be used for any solvent applications.
Solvent recovery improves process efficiency, saves costs and simplifies the supply chain by eliminating the need to constantly purchase new solvents. Furthermore, if the recovery is performed on-site, it significantly reduces transportation costs, as well as reducing the overall supply chain burden and removing the need for expensive disposal procedures.
Modern technologies enable the recovery of very complex solvents and they are presenting solutions to contemporary global issues. For example, the rapid growth of the electric vehicle market has created a booming battery industry.
66 SPECIALITY CHEMICALS MAGAZINE ESTABLISHED 1981