The significance of substitute fuels is rapidly increasing and both the utilisation and efficient application of this form of energy is becoming ever more important. By utilising so-called “refuse derived fuels” or secondary fuels, a wide range of materials made of general, industrial and commercial waste find reutilisation as energy sources in various incineration, cement, lime and lignite plants as well as – for the most part – in industrial power plants. Moreover, they find a new application as fuel in Refuse Derived Fuel (RDF) power plants.
These refuse derived fuels not only increase in value as a result of the form in which they exist, and of the class, according to which they can be categorised, but also as a result of how exactly the heating value which they provide for the combustion process can be determined.
Refuse derived fuels are evaluated according to different criteria and standards, and are categorised correspondingly. One of the most relevant parameters in this is the heating value, the calorific value as well as its moisture metrics. In addition to these values the ash, chlorine and mercury contents, heavy metal, such as copper, lead and manganese, carbon, hydrogen, nitrogen and sulphur are called on for assessment.
Depending on the storage and composition of the refuse derived fuels, relevant parameters such as moisture within the material can change.
In order to be able to evaluate or even avoid any additional costs, such as, for example, the supplementary burning of fuels like coke in the plant, process control is needed, which can better qualify and analyse the starting material, as has been the case so far.
In addition to this superior process regulation, a quality control check can be made right away by the supplier, so that all further steps in the process can be better managed and efficiency is controlled before the material is used in the plant. This verification of the suppliers is an additional benefit, which can save the company costs on fuel and can improve the return on investment.
Currently, measurements to analyse material streams consisting of refuse derived fuels are carried out in the laboratory. This practice has the disadvantage that the intervals between the individual measurements are too long. As a consequence, the time to react to the changing properties of the material stream in the plant is too long to be able to execute accurately and to make necessary adjustments in the process.
Since the measurements in the laboratory do not shed light on the entire product stream due to their unfavourable temporal distribution, but only show a small excerpt – a snapshot – the reasonable continued use of the recorded data for the running process analysis is not guaranteed. Consequently, the small amount of material which is examined in the laboratory does not allow for any sound conclusions on the tonnage of processed materials. If you want to draw conclusions from the analysis of the processed materials, the EVK Smart-Sensor-Systems offer this capability by measuring the product stream directly in line with the given environmental conditions in real time.
In order to make the leap from pure data acquisition to a finished in-line capable analysis model, the EVK solution package is expanded by the EVK SQALAR software package, which was awarded the Top Innovators Award 2018 by InVision magazine and which is used for the processing of the reference data ranges and the generation of the subsequent model for analysis.
Due to the precise measuring method of the EVK Hyperspectral Imaging Systems in the light wavelength range from 950nm to 1,700nm and evaluation with the newly developed EVK SQALAR software, it is possible to achieve measurements with a high correlation between the lab measurement values and the measurements by the HELIOS Class Hyperspectral Imaging System directly on the line.
Dr Matthias Kerschhaggl, Chief Technical Officer at EVK explains, “We are in the position for the first time to connect precision analytics from the lab with immense quantities of data from inline monitoring and, in this way, to soundly qualify the product streams quantitatively. One could say that we’re bringing the lab to the line.”
There is a great deal of interest in EVK’s development. The solution not only holds plenty of potential for improved process monitoring, but also subsequently furthers the ability to better evaluate and plan the company’s energy efficiency.
Thus, modern companies actively take up the issue of environmental awareness and sustainability through the application of smart sensor-based systems. For example, this supports compliance with EU directive 2010/75/EU, regarding the combustion and co-combustion of waste materials.
With the combination of application software, a smart camera and the necessary know-how, companies like EVK – thanks to their longstanding expertise – have the possibility to offer a comprehensive solution concept in sensor technology and patent it for the market.
Technologies in the area of hyperspectral analysis and solutions in the field of refuse derived fuels arising thereof, have a great chance to catch on in the next few years and, as a result, to pave the way for more effective process analysis and process monitoring in the interests of the environment, profitability and the sustainability of innovative solutions in the recycling sector!