The F-CUBED Project: feasibility study of bio-sludge hydrochar as blast furnace injectant

The steel manufacturing industry is one of the largest and most important industrial sectors in the world. However, it is also one of the most energy-intensive and highest coal-consuming industries, which has a significant impact on global CO2 emissions. One of the aims of the F-CUBED project is to convert paper sludge into an energy carrier suitable to be used as an injectant in blast furnace processes.
Biological (bio)-sludge from paper mills is a biomass residue with huge annual output that is produced throughout the year and contains a large amount of organic matter. The discharge of this sludge into the environment can have serious polluting effects. Therefore, using bio-sludge as an energy source in blast furnace injection processes can both reduce waste streams generated from paper manufacturing and contribute to the sustainable development of the metallurgical industry.
Previous studies of bio-sludge have shown that it has low energy density, low calorific value and high alkali metal content, which greatly limits its direct use, meaning it must be treated to improve its energy density for subsequent use as a blast furnace injectant. Hydrothermal carbonisation...