Generating electricity and heat from high-calorific waste

Fuel mixture

Wood chips are mixed with the plastic waste in a defined ratio before entering the fuel lock and continuously introduced into the upper part of the reactor. Fine lime is also added, which acts as a reactant for the pollutants released in the process, such as sulfur or halogens (chlorine, bromine). The wood chips serve as a supporting structure in the process and ensure good gas permeability of the reaction moving bed.

Proceedings

The moving reaction bed flows through the reactor under its own gravity. The thermal splitting of the fuels takes place in the so-called pyrolysis zone. This produces pyrolysis gas and pyrolysis coke as reaction products. These flow together further down into the oxidation zone (co-current gasifier). In the oxidation zone, the pyrolysis products are converted by supplying oxygen. Partial combustion takes place with the air and the combustible reaction partners, which generates the reaction temperature of over 1200 °C in the oxidation zone. This is also referred to as an autothermal (energy self-sufficient) process. The feedstocks are converted into gas at a temperature level of 1200 – 1400 °C in the presence of lime to bind the impurities, whereby these pollutants are concentrated in the ash and removed harmlessly from the process.