Patent DE-102007051994-A1 (DE)
Title: Production of artificial fuel, involves processing mixtures of waste materials of high and low calorific value to form stable briquettes which can be burnt with coal or as the sole fuel, e.g. for power stations
IPC: C10L5/46
Filed: 2007-10-31
Abstract: A process for the production of artificial fuel from waste materials of high calorific value (e.g. from waste disposal) and configuratable filling binders of low calorific value (e.g. from industry, agriculture or forestry), involves 3 stages with 8 coupled steps comprising metals removal, pulverisation, sieve classification, processing and mixing of various fractions, compaction and extrusion to form briquettes which can be burnt with coal or as the sole fuel, especially in power stations. A defined artificial fuel production process (DEBE process) in which definite amounts of unfabricated materials of high calorific value (HCM) arising from old car recycling, environmental services and waste disposal, with the addition of configuratable filling binders of low calorific value (LCM) arising in the production of goods and services in the local economy, industry, foodstuffs, agriculture and forestry, are processed in 3 stages with 8 steps coupled together, through which the above pre-product streams pass in a definite sequence so that they are subjected, in each step during materials separation and/or combination, to the mechanical/physical action of the known apparatus and equipment used, to give high-quality artificial fuel (EBS) in the form of stable, compacted briquettes. In this process, (1) HCM comprises light shredder fractions (0-60 mm) from old car processing, oversize sieve fractions (0-60 mm) from composting, 0-60 mm fractions from mechanical biological waste treatment (MBA), fractions from the German Dual System (DSD) and other processed high-calorific materials from environmental services and waste disposal; (2) LCM comprises predried sewage sludge, fermentation residues, biocompost fractions and other processed substrates from the above sources; (3) the production sequence for EBS comprises (i) conversion of HCM (feed material and pulverised material) and the fine intermediate fraction (0-20 mm) to a high-calorific fraction A (SLF A, 0-20 mm, as a mixture of fluff, textile fibres, foam, film and wood) and to a high-calorific fraction B (SLF B, 8-20 mm, as a mixture of plastic and rubber), from step 1 to step 5; (ii) predried homogenised slurry mixture from step 6 onwards; (iii) oversize sieve fraction (0-20 mm) from composting, from step 6 onwards; (iv) moist agglomeration mixture (MAM) and SLF B (0-20 mm) from step 7 onwards; (v) configuratable agglomeration mixture (CAM) to final product (ESB) from step 8 onwards; (4) the MAM is premixed in step 6 from (based on pre-product mixture) at least 1 vol.% SLF A, at least 1 vol.% predried homogenised slurry mixture and at least 1 vol.% oversize fraction from composting (0-20 mm); (5) the CAM (v) is mixed and homogenised from (based on MAM in step 7) at least 1 vol.% MAM, 0 vol.% or more SLF B, 0 vol.% or more of the 0-20 mm fraction from MBA, 0 vol.% or more of the 0-20 mm fraction from DSD and 0 vol.% or more of the 0-20 mm sieve oversize from composting; (6) the assignment and checking of all material documents/declaration analyses, sampling for setting up control analyses, and visual and/or organoleptic checks on the starting materials (HCM and LCM) is carried out in process stage I (VST I for pre-product mixture reception), and the HCM or high-calorific starting fraction reaches process stage II (VST II/mechanical separation for further processing) which consists of 5 steps; (7) step 1 of VST II, (ferrous metals separation) involves classifying the HCM according to magnetic properties with the aid of known magnetic separators; (8) step 2 of VST II involves the separation of non-ferrous metals with an electrostatic field produced in a known electric separator, which deflects solids from the HCM according to conductivity, extracts them as conductors, semiconductors or non-conductors and transfers them to intermediate storage; (9) step 3 of VST II involves pulverisation of the 0-60 mm fraction of feed material in a pulveriser; (10) step 4 of VST II involves classification of the pulverised material, e.g. by sieve separation to give a 0-20 mm fraction which is transferred to step 5 for grading and oversize material (20-60 mm fractions) which is returned to step 3; (11) step 5 of VST II (grading) involves separating the pregraded fine intermediate fraction according to density in an aero-separator in which a fluidised mixture of particles and air is subjected to the action of flow, frictional and inertial forces, so that the heavy fraction (SLF B) collects on the separator plate and the lighter fraction (SLF A) flows over the plate; (12) step 6 in the third stage (VST III) (premixing) involves mixing the SLF A from step 5 with previously processed LCM (e.g. predried sludge) from VST I to give a moist mixture (MAM); (13) step 7 (VST III; adjusting to the required constant EBS calorific value) involves mixing and homogenising the MAM with processed oversize material from composting and other definite amounts (by volume) of MBA, high-calorific or DSD fractions from VST I and SLF B from VST II (step 5), to give a finely-dispersed system of high stability; (14) step 8 (VST III) involves compaction by moulding in presses, extruders or other suitable processors; (15) the mixture from step 7 is pressed through a perforated die in a processing extruder to form EBS rope which breaks apart by itself to give dimensionally-stable EBS briquettes of unequal length; (16) the product (EBS) shows a diameter of 25-30 mm, a length of 30-60 mm, a calorific value of at least 11000 kJ/kg, pollutant contents of less than 5% for chlorine compounds and not more than 3-5% for heavy metals, a water content of less than 50%, a strength of at least 4 N/mm 2>and a shatter strength of more than 74%; (17) the final product can be burnt with other fuel.