ADIOX® dioxin removal is an effective, safe and economical technology for scrubbing dioxins from gases. ADIOX® material can be incinerated after use, and the dioxins are then destroyed and removed from the ecosystem. ADIOX® can be installed in scrubber systems or other types of equipment in a flue gas cleaning system and in installations for the thermal treatment of:
- Municipal waste
- Industrial waste
- Hazardous waste, especially waste containing chlorine
- Steel and metals
ADIOX® technology separates dioxins from gases through absorption/adsorption in a polymer material. The material consists of polypropylene doped with carbon particles. The dioxins in the gas are first absorbed by the polymer and then diffused into the carbon particles, where they are adsorbed.
ADIOX® is produced and delivered in the form of tower packing and droplet separators, with all the conventional advantages these provide. They can be installed in ADIOX® in scrubbers and also in dedicated dioxin removal absorbers where the gas is dry or saturated (semi-wet operation). The material is installed in various applications:
- Wet ADIOX® scrubbers
- Semi-wet (moisture saturated) ADIOX® absorbers
- Dry ADIOX®absorbers
- ADIOX® droplet separators
ADIOX® is especially well suited for avoiding the so-called dioxin memory effect (see below) or where a multi-functional solution is required with integrated separation ofHCl, SO2, HF, Hg and dioxins, in combination with substantial energy recovery through flue gas condensation.
ADIOX® is available in different sizes and types of tower packing such as knitted mesh droplet separators and lamella demisters. The material is supplied in bulk to end users for installation in existing scrubbers and as components in upgrades or new flue gas treatment plants.
ADIOX® offers many advantages:
- If existing tower packing and droplet separators are replaced with ADIOX®, the memory effect is effectively reduced.
- Extremely high availability inherent in passive systems.
- Can be cost-effectively integrated into conventional tower packing scrubber systems.
- Equipment for extra removal requirements such as a final dry or semi-wet absorber is easily added.
- ADIOX® leaves no residual products as the material is incinerable.
- Dioxins are destroyed in incineration
- Long replacement intervals for tower packing material
- Competitive operating economy
ADIOX® analysis package
We offer our customers an inspection program in which the material's dioxin content, surface and mechanical qualities are regularly analyzed (usually once annually). The purpose of this procedure is to ensure the installation is functioning well and that the material enjoys maximum economic use. The test results are presented in a report and following repeated analyses, an absorption history is presented for each stage.
Dioxin memory effect
Dioxin is absorbed efficiently by various polymers such as polypropylene until equilibrium is reached, which means dioxin desorption can also take place Typically, dioxins are absorbed during operational disruptions or start-ups when concentrations are high, to be released again during normal operations when concentrations are lower. Small temperature variations can also lead to absorption/desorption equilibrium displacements. This phenomenon is called the memory effect, and can lead to problems in staying under dioxin limits. ADIOX® is often used to minimize the memory effect.
Dioxins in equilibrium between gas and polymer (left). Dioxins are absorbed in the polymer and bound to the carbon particles (ADIOX, right)
Condensing scrubbers are often installed downstream of dioxin removal equipment such as baghouse filters with carbon dosing. The memory effect in installations with conventional polypropylene tower packing sometimes leads to dioxin emission limits' being exceeded. Replacing tower packing and droplet separators to ADIOX® versions of the same is an effective way of minimizing the memory effect, typically by more than 90%.
Absorption of PeCDF in polypropylene test rods exposed for one year in flue gas with approx 10 ng TEQ/Nm3 d.g. The subsequent desorption took place in flue gas with 0.1 ng TEQ/Nm3 d.g. The results are published in Andersson S. & Löthgren C-J. “Numerical modelling of the memory effect in wet scrubbers”, Chemosphere, Vol. 73 (2008), pp. S101–S105