Charcoal or other carbonaceous solid organic materials react at high temperatures with steam to produce carbon monoxide and hydrogen.
This generated gas, which is called "syngas" (from synthesis gas), is combustible and often used as a fuel source or as an intermediate for the production of other chemicals.
In a simple direct process air is used for partly combustion. Better but more expensive is the using of oxygen, for reducing the NOx emissions and also keeping a good gas quality.
Application: Activation
Used temperature below 1000°C but over 600°C allows an (partically) gasification process. By adding off steam in the (pyrolysis) reaction chamber some of the carbon atoms will be get off the grid and the active surface of the grid will increased.
At temperature of 800°C appr. 30% of the carbon will get off the grid and the surface will be inceasing up to 300 - 400 m²/gramm.
Application: Syngas Production
In contrary to the activation all carbon atoms should be go into the syngas, so that the output product will only be ashes.
The syngas can used for production of methane and this can be used for Fischer-Tropsch-process.
Carbon Recovery Unit (Direct Heated Rotary Kiln)
The solid residues of a waste pyrolysis process often contain a lot of chemical bound energy. This energy could be used by a so called "Carbon Recovery Unit" (CRU). The gasification takes place in a rotary kiln. The ratio of the feeded air and steam has to be balanced to heat up the char to approximately 900°C.
The exothermic reaction of atmospheric oxygen with carbon is compensated by the endothermic reaction of steam with carbon. The so called Boudouard reaction, which describes the composition of the gas, is influenced by the temperature and the oxygen content. The obtained syngas is incinerated in a downstream combustion chamber. The thermal energy of the flue gas is converted in further process steps into electric energy.
Indirect Heated Rotary Kiln
In the indirect heated (DGE-)process the required heat for the synthesis process will transfered over the kiln shell, so a mostly clean syngas will be produced, which is usefull for the chemical industy.
Fluidized Bed Reaktor
The produced thermolysis/pyrolysis coke is fine grained coke with minimum of sulphur and chlorine. So it is the best raw material for a fluidized bed.
The process heat for the fluidized bed can be given from the thermolysis off gas.
