The Schwelgern coke plant (KBS), ThyssenKrupp Industrial Solutions and Berlin Technical University (TU Berlin) have installed a pilot plant on the works site of ThyssenKrupp Steel Europe in Duisburg to produce ammonium bicarbonate, which can be used as baking powder.
The project initially aimed to convert process gases generated during the production of coke into marketable materials such as fertilizers and chemical propellants.
It reduces carbon dioxide (CO2) emissions as well.
“There are coke plants all over the world. With this newly developed process we want to give operators the chance to put their process gases to good use and increase the productivity of their plants,” says Dr Holger Thielert, head of gas treatment plant department at ThyssenKrupp Industrial Solutions.
“For this we have developed and patented a process that converts coke oven gases into valuable materials in an eco-friendly way.”
“We can market this process worldwide and also retrofit it in existing plants.”
The new process starts with the production of coke, alongside iron ore the most important charge material for producing pig iron in the blast furnace.
“For this, coal is ‘baked’ at high temperatures in the coke plant,” he says.
“The hot gases generated by this process contain a number of substances.”
“The pilot plant uses a complex process to scrub the coke oven gas. Adding carbon dioxide produces ammonium bicarbonate.”
The end products can be put to a range of uses such as nitrogen fertilizers, propellants and foaming agents for plastics or porous ceramics, and also in the food industry.
Scaling up
Following successful tests in the laboratory, two researchers from TU Berlin were tasked with building the pilot plant in Duisburg.
“The key tests can only be carried out under real conditions,” says Sebastian Riethof, a scientist from TU Berlin.
“If everything goes to plan here at the coke plant, the new process can also be used on an industrial scale.”
“We are able to utilize 95% of the ammonia contained in the coke oven gas,” he says.
“Every hour the process produces 15 kg of solid materials from 15 m3 of coke oven gas and two m3 of CO2.”
Pilot plant reduces CO2 emissions
If the tests continue successfully, this would be a real breakthrough in productivity and resource efficiency – also for the Schwelgern coke plant.
“Here in Duisburg, almost all process gases are already being recycled efficiently,” says KBS MD Peter Liszio.
“If we can now manage on a long-term basis not only to produce marketable products from the coke oven gases for other sectors but also to reduce the CO2 emissions of the mill, which would be real value added with great environmental benefits.”
