Vattenfall has found a way to reduce corrosion and deposit problems in biomass-fired combined heat and power (CHP) plants and waste incinerators. The technical solution, ChlorOut, can also help reduce emissions of nitrogen oxides and dioxins.
The concept is based on the measurement of corrosive alkali chlorides in the flue gas with a unique instrument called IACM, and the dosing of sulphur-based additives to convert the chlorides to less harmful sulphates.
ChlorOut AB, a wholly-owned subsidiary of Vattenfall, was established in February 2011 to market the technology outside the Vattenfall Group. To do this, ChlorOut AB needs to cooperate with commercial wholesale suppliers of boiler plants. A major step forward was the agreement with international technology group Andritz, one of the leading suppliers of biomass boilers for bioenergy applications.
The agreement gives Andritz a worldwide license to use ChlorOut for the building of new Bubbling Fluidized Bed (BFB) boilers and existing units retrofitted into BFB boilers, both for combustion of biomass fuels.
“The agreement is of great significance to ChlorOut AB,” says Dr Magnus Berg, Managing Director at ChlorOut AB.
“The solution has been successfully implemented and validated in a number of existing boilers, but this opens the market for installations in new plants. We know that biomass combustion often results in corrosion and deposit problems – so why wait with implementing the solution until the super heaters are already damaged?”
Mr Seppo Hulkkonen, Technology Director at Andritz, says that ChlorOut opens up for more flexibility and tolerance in terms of fuel quality.
"This helps us and our customers. Corrosion prevention and emission reduction are the key technical challenges that we face in most projects.”
The collaboration has already resulted in a contract to install the ChlorOut concept in a CHP plant in Poland, which is being converted into a BFB boiler firing biomass. The system will also be utilized in a large biomass project in the UK.