Solvents

Solvents are substances that are suitable for dissolving gases, liquids and solids without themselves reacting chemically with these substances and thus changing them. The best-known solvent is water. Organic solvents are also used very frequently, e.g. for paints and varnishes. Most of these are flammable, sometimes even explosive substances with a boiling point of up to 200°.

Organic solvents in particular are highly volatile, with some gassing out over months or years.

Most solvents are a problem from a health point of view. Humans can absorb them through the respiratory tract or the skin, whereupon they can accumulate in the brain, liver, kidneys, bone marrow and lead to organ damage. The liver, kidneys and central nervous system can be damaged by solvents.

Solvents belong to the group of volatile hydrocarbons and are covered in this context by the TA Luft. Volatile hydrocarbons are also referred to as VOC (volatile organic compounds), TOC (total organic carbon) or total C (total C).

The TA Luft sets limits of 500 g/h in the mass flow and a mass concentration of 50 mg ppm.

The conventional process for neutralizing solvent gases is thermal aftertreatment. For this purpose, the gases contained in the exhaust air are concentrated and then burned with the addition of natural gas. Thermal post-treatment thus requires high energy input and in turn produces pollutants.

In the case of pure solvent exhaust air, e.g. from printing plants, solvents can also be recovered from the exhaust air.

oxytec replaces the energy-consuming thermal post-treatment by photolysis oxidation with UV ozone. The combination of direct exposure to UV light and the free radicals generated by UV light achieves a high effect. In individual cases, it may make sense to supplement the process with our wet scrubbers or to rely on the even more effective plasma technology, which we are the only company to also offer for the industry’s large line cross-sections.

• Very effective
• Little space required
• Much lower energy consumption than thermal processes
• Very low maintenance