Green anode plant activities for aluminum smelters generate harmful vapors containing CTPV (Coal Tar Pitch Volatiles). These volatiles include a large fraction of PAHs (Polycyclic Aromatic Hydrocarbons) that are suspected to be hazardous for health and environment.
Fives’ installations aim at limiting operators’ exposure in the working area and at complying with the most stringent environmental standards in terms of emissions at the stack. Fives supplies proven technologies for a clean Paste Plant.
Fives has developed Eolios, a system that optimizes the combination of:
- A dry scrubber (DS) based on the adsorption of PAH on coke fines
- A Regenerative Thermal Oxidizer (RTO) using oxidation technology
A conventional coke dry scrubber treats the bulk of the air volumes extracted from the anode forming equipment. Additionally, a small size RTO, which can be coupled to a pre-filtration unit, is dedicated to the treatment of high PAHs concentrated streams originating mainly from the anode paste coolers.
Eolios, an innovative solution for optimum emission performance:
- The best PAHs abatement rate: AH16 [NS 9815] < 1 mg/Nm3
- Minimized energy consumption
- Minimized carbon footprint
- Maximized pitch fume treatment efficiency
- Low operating costs
- The lowest CO2 emissions
- High reliability and operation flexibility: by-pass to dry-scrubber
A conventional system for an efficient and practical capture
Fives’ conventional Pitch Fume Treatment System consists of a Dry Scrubbing unit using the coke fines readily available in the carbon plant to absorb the pitch fumes. Such system is derived from the potline alumina dry injection scrubbing technology.
- The fines are injected counter-currently to the charged fumes inside a Venturi reactor.
- Pitch fumes loaded fines are then collected through a bag filter and are reintroduced into the anode paste recipe.
The process does not imply any product loss.
In the last 30 years, coke injection dry scrubbers have been recognized as being the most practical solution in Green Anode Plant.
Emissions Treatment Technologies
HF Abatment & Alumina enrichment
Treatment of pollutants and supply of fluorinated alumina
Treatment of fumes coming from anode baking furnaces