Innovation: Dioxin destruction by CataFlexTM DiOxi catalytic filter bags.
At a new medical waste incinerator in Thailand, a desire to safely and securely handle dioxin emissions has led to the installation of CataFlexTM DiOxi catalytic filter bags in the beginning of 2018.
Dutch Incinerators, who provides turn-key solutions in thermal waste processing and waste-to-energy, was constructing a medical waste incinerator in Thailand. Based on their extensive experience in the medical and hazardous waste market, they knew that dioxin formation during the combustion process is a challenge. Even when following best practice and using state-of-the-art technology, very little has to deviate for the dioxin formation to end above the very strict regulated limit. Adsorption by activated carbon is the most widely used technology for the capture of dioxins at waste incinerators. However, this technology also has limits, which mean that plant operators and management always doubt whether they are in compliance or not. Online measurements of dioxins are currently not possible, and this means that activated carbon is in practice added in fixed quantities during the operation of the plant. Experience however tells that inlet quantities of dioxins vary significantly, both as a function of the type of waste and the operating conditions of the combustion process. Furthermore, it is also known that increasing the capture of dioxins by increasing the activated carbon injection is not always possible. Dutch Incinerators has previously experienced in an existing plant with similar setup that dioxin emissions could not be pushed below the local regulation of 0.5 ng-TEQ/Nm3 even by dosing 10 times more activated carbon. In fact, the increased activated carbon injection hardly had any effect. On top of this, activated carbon only captures the dioxins and poses a new risk when handling the spent activated carbon – now containing dioxins.