What's the secret behind the top-performance in waste recovery at ENCI-Maastricht?
"Vision" and "passion", that are the key-words behind the extra-ordinary results that ENCI achieves in alternative fuels- and raw material usage. In the early sixties the plant started as one of the first kilns in Europe to co-process shale, a residue of the local mining industry. A next remarkable step was made in the nineties, long before the word biomass and CO2 trading became popular, by utilising the potential of sewage sludge as a fuel and raw material substitute. Today, the plant is still experimenting with new waste streams in order to remain competitive in financial and ecological terms.
Early mover in recognizing the value of waste
The oil crisis of 1973 was still "unthinkable" when ENCI decided to start co-processing shale, a residue from the local mining industry. Although the heat value was extremely low, due to the high ash-content, the entrepreneurs of ENCI believed that it was possible to produce high-quality clinker with this material in the fuel mix, as long as the shale was grinded fine enough. Significant investments were made in grinding equipment and storage and feeding lines. Finally it turned out to be a big success and the shale usage lasted till 1999, so more than 30 years!
By using the shale the management, engineers and operators learned to trust "low quality" fuels. Next to this, a good relation was build with the Flame-Institute in Ijmuiden, that could simulate the burning behaviour in a small scale kiln.
Early mover in biomass wastes
In the nineties, the landfilling and use as fertilizer of sewage sludge was banned in the Netherlands, due to risks associated with it. ENCI initiated a platform with all sludge producers in the area to investigate potential solutions. Although the sewage sludge, even after drying, would have a low calorific value, the ENCI-engineers were convinced that it would work. At that time there was no CO2-trading market, so no-one was interested in this biomass. ENCI however investigated intensively the burning behaviour, health and safety-aspects and made large scale pilot tests. It was the first plant in the world that started to grind sewage sludge.
Finally all this entrepreneurial work in technology ànd in developing a public private partnership with the waste water treatment company in Limburg, resulted in a unique feature: until today, the plant is replacing 30% of its primary fuel by sewage sludge.
Early mover in exchange of knowledge
Already in the nineties the cement plants recognized that sharing non-commercial knowledge gives mutual benefits. Becoming part of HeidelbergCement, ENCI-engineers were well prepared to share the knowledge with other plants within the Group. Meanwhile, the knowledge of ENCI has been very helpful for sewage sludge applications in Germany, USA, Belgium, Czech Republic, Turkey, China and Sweden. On the other hand, ENCI benefitted from the knowledge in HC-Group on valorising hazardous waste.
Development of application of sulphuric acid ammonia residue
The experience of HeidelbergCement in hazardous waste usage is a considerable support in the current evaluation of the use of ZA-oil, a residue from a sulphuric acid ammonia plant that is operated by the chemical multinational DSM. The material has been carefully analyzed on its composition and health and safety aspects.
The ZA-oil will be stored in a separate tank and will be supplied by a just-in-time principle. In order to make that possible a transparent and professional agreement and cooperation with the waste management company involved is key.
The visitors of ENCI on 7 march as part of the Global Fuels Conference in Aachen will be able to see also this new facility in operation.
For more information:
Jan Theulen
Global Waste Co-processing Manager
HeidelbergCement
jan.theulen@heidelbergcement.com
Frans Erens
Director ENCI-Maastricht
HeidelbergCement
FErens@enci.nl