Wast solvent recycling or solvent waste management?

Waste solvent recycling is a key process for reducing environmental impact and improving efficiency in industrial production. Understanding how solvents are recovered, purified and reused helps companies comply with environmental standards and significantly reduce costs.

A solvent is a liquid capable of dissolving various substances to form a solution. In chemistry, solvents play a crucial role in industrial manufacturing, cleaning, and formulation. Because many organic solvents are volatile and potentially hazardous, their use, storage and recovery require strict technical and environmental controls.

Solvents are chemical substances that dissolve solids, liquids or gases without altering their chemical composition. They are widely used in chemical, pharmaceutical, and coating industries, as well as in cleaning and extraction processes.
Depending on their polarity, solvents are classified into:

• Polar solvents, with a high dielectric constant (e.g. water, dimethyl sulphoxide).
• Non-polar (apolar) solvents, with a low dielectric constant (e.g. hydrocarbons such as hexane).

Solvents are indispensable in various chemical reactions and applications — from paint production and printing inks to adhesives and metal degreasing.

Proper solvent waste management is essential to prevent environmental contamination.
In the European Union, the disposal of solvents is regulated by strict environmental laws, such as Directive 2008/98/EC and national waste management decrees (e.g. Italy’s Legislative Decree 152/2006).

Solvents are typically classified as:

• Halogenated solvents – complex and expensive to dispose of;
• Non-halogenated solvents – easier and cheaper to treat or recycle.

In laboratories and production facilities, waste solvents are collected in durable, clearly labeled containers, safely stored, and later processed by certified waste management companies through controlled incineration or solvent recovery systems.

In the industrial sector, recycling is the preferred option, as it allows companies to recover and reuse large solvent volumes, saving costs while minimizing environmental footprint.

Waste solvent recycling involves regenerating used solvents for reuse in industrial processes.
This recovery can be achieved through different technologies, depending on the solvent’s composition and purity requirements.

1. Fractional or Continuous Distillation

Distillation separates solvent mixtures based on boiling points, producing purified solvents that can be reintroduced into production cycles.
Brofind® designs batch and continuous distillation units operating at different temperatures and pressures to ensure high-purity solvent recovery.

2. Molecular Sieves

Used to remove water traces from hygroscopic solvents, molecular sieves enhance the quality of recovered compounds, making them suitable for direct reuse.

3. Gas-Phase Recovery

Since many solvents are volatile, they often evaporate during production.
Gas-phase recovery systems capture solvent vapors, condense them, and return them to the manufacturing process, minimizing loss and emissions.

In some cases, complete purification may not be technically or economically feasible.
Recovered solvents can still be used for secondary purposes such as equipment cleaning or maintenance operations.

As a last resort, solvents can be safely incinerated in controlled conditions — a technically valid but less sustainable option compared to recovery and reuse.