What is refuse derive fuel? Refuse-derived fuels (RDF) or secondary fuels (SRF) are fuels obtained from waste. This can be solid, liquid or gaseous waste, which is processed to different degrees of depth for the respective purpose. The waste usually catagorized as household waste, industrial waste, and production waste.
The processing steps of the high-calorific fractions from commercial waste and household waste include pre-sorting, coarse crushing, screen classification, and fine shredding, and briquetting. Multiple air classification and metal separation are necessary to remove unwanted impurities.
Additional steps for the production include sensory sorting and drying.
Among all steps, size reduction by shredders is the priority. A good shredder is robust enough to break down materials, as well as, size reduce them to appropriate size. The first task is achieved by double shaft shredder. The high torque and coarse output render it the best choice as the primary shredding. Bulky objects like bags, furniture and bales can be disintegrated at the very beginning. The second task is done by a single shaft shredder, whose screens define the output size and capacity.
Taking in all the machines, with the aim of getting high caloric, low moisture and appropriate size refuse-derived fuel. These 3 factors determine the value of the fuel.
As RDF contains high caloric values, it is an alternative to fossil fuels. For example, power plant consumes such fuel.
RDF is utilized together with conventional fuels in so-called co-combustion, mainly in cement, lime, lignite and, to a large extent, in industrial power plants (high calorific value fraction) as well as in waste incineration plants or as the sole fuel in RDF power plants. The appropriateness of using RDF should be assessed, in addition to sustainable use, by comparing the energy efficiency of energy and material recovery.