A CLEAN AFFAIR
How Evonik’s P84® polyimide fibers contribute to less CO2 emissions
Concrete is a jack of all trades among building materials - versatile and effective. In addition to water and other components, it consists of cement, which is produced in energy-intensive special cement kilns. The highly efficient filter media made of polyimide fibers P84® from Evonik keep the release of dust particles during cement production below emission limits.
When the ancient Romans invented opus caementitium, the predecessor of concrete, they could certainly not have imagined that people would still use it as a construction material some 2000 years later. The Viaduct, the Pantheon, and the Elbe Philharmonic Hall are made of this universal building material.
There is almost nothing that cannot be built with concrete. The building material owes its popularity to its flexibility and nearly unlimited application possibilities and is able to absorb high compressive forces.
The basic mixture nowadays contains cement, aggregate (sand, gravel) and water. Although the industry makes efforts to turn it into a relatively ecological building material, cement production is energy-intensive and releases a lot of dust particles. In cement plants, raw materials such as limestone, clay, sand and iron ore are fired in special kilns in a continuous process. These materials are then finally ground after adding gypsum, which delays the curing speed.
FILTER MEDIA FOR EFFICIENT HOT GAS CLEANING
To reduce fine dust particle emissions to the required emission limit, filter bags are used for hot gas filtration – for example made from the high-temperature-resistant polymer by Evonik. P84® polyimide fibers are well known for their high filtration efficiency thanks to their multi-lobe design and high surface area. They retain a much higher permeability throughout their lifecycle. This results in significant reductions in the energy consumption of the fan that keeps the gas flow at a constant level.
Filter media made of P84® polyimide fibers by Evonik therefore not only cut back on fine dust particle emissions, but also reduce energy costs.
Worldwide, more than 150 cement kilns are cleaned with P84® filter bags. In China alone, about 100 cement plants rely on polyimide fibers from Evonik. Based on the energy savings, the reference plants of Evonik reduce CO2 emissions by approximately 60,000 metric tons a year.