Projektflyer - Lehr- und Forschungsgebiet Technologie der ...

Biochar for
Foundry processes
Unit of
Technology of Fuels
Prof. Dr.-Ing. Peter Quicker
Wüllnerstraße 2
52062 Aachen
Contact
Dipl.-Ing. Guillermo Pena Chipatecua
Phone: +49-241-80- 90714
Fax: +49-241-80- 92624
pena@teer.rwth-aachen.de
www.teer.rwth-aachen.de
Biochar for foundry processes
Background
The cupola furnace is a melting furnace for the production of cast iron out of raw
iron. Beside raw iron, there are also steel scrap, recycled metals and foundry coke
which are used in the cupola furnace. The main tasks of the foundry coke in the
cupola process are the supply of energy and the use as recarburizer. The price of
foundry coke was ca. 550 €/t in May 2011. Through the use of foundry coke for the
process, 1.5 M tons of CO2 were emitted in 2011.Hence, companies are not only
burdened by the high prices of foundry coke but also by the CO2-certifcat system. As
a result, operators of cupola furnaces are looking for alternative substitutes for
foundry coke.
Objectives & approach
A promising alternative carbon carrier for the use in a cupola furnace may be
biomass residues, which can be converted into higher class carbon products by
thermo-chemical conversion processes such as pyrolysis. Through the use of
biogenic input material, fossil resources may be saved.
As part of the research project at the Unit of Technology of Fuels, possibilities for the
substitution of fossil carbon carriers (foundry coke, dust coal) by biogenic
carbon/coke are investigated. In a first step, several biomasses (straw, bark, green
waste, wood residues, nut shells, etc.) shall be pyrolysed in pilot scale rotary kiln to
investigate the pyrolysis capacity and the properties of the obtained carbonization
products. As the carbonization products from the biomass pyrolysis are, other than
coke from hard coal, only available in insufficient grain sizes, the carbonization
products further need to be briquetted to serve as a substitute for foundry coke.
Subsequently, several tons of biogenic carbon carriers from selected biomasses
shall be produced in a pilot scale rotary kiln. The produced carbonization products
will be briquetted, tested and analyzed in industrial cupola furnace trials.
Project status
The pilot scale pyrolysis tests have already shown that different biomasses can be
converted into carbonization products with higher carbon contents through the
thermo-chemical conversion. For the production of biocoke for the foundry process,
especially woody residues have proved to be suitable. The briquetting of the
carbonization products is possible with the addition of binding agents and leads to
satisfactory stability of the briquettes for the use in a cupola furnace.
Currently, the pilot rotary kiln pyrolysis plant is set up in the district of Aachen in
order to supply necessary amounts for the industrial melting tests. Subsequently, the
industrial briquetting of the biocoke is carried out to evaluate the partial substitution
of the fossil foundry coke and the relevant indicators with regard to practical
application.