EnviroTech 2020

July 14, 2020

An online conference focusing on the latest technologies and best practices for reducing the cement industry's environmental footprint


KHD's special solutions for AFR substitution and NOx abatement

As more and more countries adapt and benefit from proven equipment solutions for alternative fuel usage, other developing countries still do not have sufficiently developed systems for the collection, preparation and utilisation of alternative fuels. Therefore, cement producers who want to increase their alternative fuel rate and maintain a sustainable and competitive production require better and more efficient solutions, especially those who are robust enough to handle even less pre-processed waste streams. To fulfill this demand, KHD developed a rotary combustion reactor called PYROROTOR®, a product that helps plant operators to reduce alternative fuel preparation costs by the biggest possible extent.

Pyrorotor is able to process almost all kinds of alternative fuels, from the coarsest waste matter to materials with extremely poor burning properties. Even whole tires can be utilised without any distinct preparation. To achieve that, Pyrorotor constantly revolves and tumbles alternative fuel to enable a sufficient retention time in high temperature (up to 1200 °C) to ensure a complete burn-out of any material.

The presentation includes operational results of KHD´s first installed Pyrorotors at Gmunden plant in Austria and the Ssangyong plant in South Korea.

For the pilot project in Gmunden, KHD implemented the best available calciner technology for alternative fuel processing, which enables the owner, Rohrdorf Zement, to produce clinker with high amounts of low-cost alternative fuels. In South Korea, KHD successfully commissioned two Pyrorotors for high AFR utilisation rates.

Another major topic of the industry is the mandatory reduction of NOx emissions. The ever more stringent emission limits have forced many cement producers to install SNCR and SCR-technologies which can be quite CAPEX-intense. However, NOx emissions can also be greatly reduced by the appropriate design of the calciner system. To acknowledge the lowest emission guidelines across the globe, an innovative gasifying reactor system called PYROREDOX® was developed by KHD to operate plants without any costly secondary measures like SCR whilst still achieving the lowest NOx emission values.

The Pyroredox system, patented by KHD, serves as a gasifying reactor which is connected upstream of the main calciner. By separation of the gasification zone from the oxidisation zone, a reduction comparable to the catalytic SCR technology is achieved.

The presentation includes operational results from China where KHD retrofitted existing plants with Pyroredox and combined it with existing SNCR systems to achieve extremely low emission levels below 30mg/Nm3. Specifically, three plants from the Tianrui Group in Weihui, Xindeng (5.500 tpd each) and Xingyang (12.000 tpd) are mentioned. In addition to the desired results for reduction in NOx emissions as well as low ammonia slippage, it should be mentioned that Pyroredox has not shown any negative effects on production output, fuel demand and power consumption.



Norbert Streit

Norbert Streit
Director Process Innovation, KHD

Norbert Streit looks back on almost 30 years of experience within the cement industry. Being with KHD for a long time means he has occupied several leading positions in the company. During his diverse career, Norbert has always focused on improving and refining existing solutions, or developing new ways to use alternative fuels and raw materials. In the recent past, due to popular demand in the industry, he has focused his work on emission abatement solutions that have helped plant operators and the whole industry to sustainably and significantly reduce harmful emissions, without deteriorating production efficiency, power and fuel demand.


Andreas Hand

Andreas Hand
Pyro Solutions Technology, KHD

Andreas Hand brings more than 30 years of experience in process engineering to the table. When he started his career in the chemical industry, back then he didn’t know that these years would serve as a foundation for his time in the cement sector. When joining KHD in 1992, after a quick stretch in plant layout and as Commissioning Engineer, Andreas quickly came back to process design. In almost three decades Andreas has contributed substantially to countless developments for KHD and occupied leading positions in various departments of the company. But throughout his entire career, his focus remained on developing solutions for a better, more efficient and less pollutant pyro process.