HeidelbergCement relies on HUBER technology for sewage sludge drying

Conceptual representation of the sludge drying plant, including peripherals

HeidelbergCement AG is a listed building materials group with around 54,000 employees in over 50 countries worldwide. With the production and trading of cement, aggregates and ready-mixed concrete, the group achieved a turnover of almost € 19 billion in 2019.

Due to the burning processes required for production and the use of fossil fuels and waste, the cement industry is generally known for relatively high CO2 emissions. HeidelbergCement has set itself the target of reducing carbon dioxide emissions by 30% until 2025. Then, the production of one ton of cementitious material should produce less than 525 kg of carbon dioxide emissions. By 2050, CO2-neutral concrete is supposed to be offered across the entire portfolio [Source: Sustainability Report "HeidelbergCement”,  www.heidelbergcement.com]

In addition to measures relating to additives and raw materials, the use of alternative fuels should also contribute to the above objectives. One such alternative fuel - and one that is CO2-neutral - is the use of municipal or industrial sludge produced during the treatment of wastewater (so-called surplus sludge). Up to now, pre-dewatered sludge - with then low calorific values - has been and is being co-incinerated in almost all cement plants in Germany.  

HeidelbergCement operates eight cement plants and three cement grinding plants, mainly in the south and north-west of Germany. One of these sites is Geseke, south-west of Paderborn. The plant consists of a quarry, from which limestone, clay and marl are extracted, and the actual cement plant where further processing into finished cement takes place. A HUBER belt drying plant for drying municipal sewage sludge is currently being designed and built at this location. The plant will consist of two drying lines and, when commissioned by the end of 2021, will dry up to 70,000 t/a of dewatered sewage sludge to up to 90% DS. Process heat is used to heat the dryer, which is generated during clinker cooling and would otherwise not be used. The dry material produced in this way has a calorific value of 8 to 13 MJ/kg and, after storage in a silo on site, is used to generate energy. This represents an optimal utilisation of excess heat for the production of CO2-neutral fuel.

 

http://www.hubercs.cz//huber-report/ablage-berichte/industry/heidelbergcement-relies-on-huber-technology-for-sewage-sludge-drying.html