A TEC’s Mjolnir mill: The future of alternative fuels preparation & burning By Pedro Montes de Oca and Jonathan Forinton

Agenda Background Mjolnir Features Plant Flowsheet Test and industrial results Link to pyroprocess

It is possible to substitute common fuels like coal 100% with municipal waste. This is being done in Europe in some plants. The thermal energy content of municipal waste is interesting at approx. 15…21 MJ/kg depending on the preparation process. Municipal solid waste breaks down and forms methane which is 21x more potent than CO 2 for global warming. During the fuels preparation process, enhanced recycling can be integrated. Solid waste as a fuel alternative

MSW is relatively similar in different parts of America The % organics and % water depends on the economic profile of the neighbourhood. MSW make-up Thermal fraction with calorific value: MJ/kg Recyclables Minerals, dirt

General Block Diagram for alternative fuels collectionstoragetransportdosingprocessing Operation Guidlines & Adjustment Process Design & Evaluation Combustion Technology Standard Alternative Fuel Preparation Technology ATEC production and process technology for utilization of alternative fuels There are 2 sections for an alternative fuels plant: 1)Mechanical handling, processing and dosing 2)Implementation in the cement kiln

Where Mjolnir product is injected TAD 4 TAD 3 TAD 2 TAD 1 Bypass Quench Main Burner COMBUSTION CHAMBER CALCINER MIXING CHAMBER Calciner Burner Kiln Inlet Burner Particle size Main burner: < 20 mm Other burner: < 80 mm Combustion Gas Temperature Main burner: > 2000°C CC-burner: < 2000°C Kiln inlet burner: < 1200°C Calciner burner: < 900°C Different sizing is discharged from different points Light fraction for kiln burner heavy fraction for calciner burner

Industrial Size Test Mill at Sommariva, Italy The mill is set up similar to a vertical roller mill system Foundation is light because moving parts are light Building footprint approx. L10 x W5 x H6 m

Mjolnir Test Mill- Main Technical Data Mill size2.5 Weight52‘000 Kg Drive Unit2 x 300 kW Rotor Speed~ 580 min-1 Capacity 6 t/h <15mm 15 t/h <50mm Feeding2 x Conveyor screws Discharge2 x Conveyor screws

Industrial Size Test Mill at Sommariva, Italy The mill allows for a gas throughput, like a vertical roller mill. This means we can effect drying and grinding in 1 step The ultra-fines are dedusted and can be separately handled and dosed to kiln system

Flowsheet Feed belt conveyor Bag Filter Condenser Outlet Gate 1 Middle Gate Bin with screw conveyors Outlet Gate 2 ID Fan Exhaust Outlet screw conveyor1 Outlet screw conveyor2 Different sizing is discharged from different points Even metals can be quite reliably separated by density

Industrial Size Test Mill at Sommariva, Italy 2 Feed belts bring material into each of the 2 shredding chambers

Mjolnir Design Features Common feed bin with 2 screw conveyors to each of the 2 mill chambers Rejects manual outlet gate Product outlet screens

Mjolnir View inside the mills

Mjolnir Features of the grinding tools The chains are individually adjustable in height and position at the shaft head depending on the input material which has to be grinded. The change in position can be done in a quick time, if it should come to a request to change the input material. The same applies if the chains have to be replaced due to wear. Incoming material < 150 mm Easy to maintain (NO KNIVES) Separated from FE and non FE materials

Mjolnir 3D Model

Mjolnir inside the test mill above, the outlet screens and on the right side the manual outlet gate left, the chains after the testing period

Mjolnir Advantages 1)Size reduction from 150mm to 5mm in one grinding step 2)Saves one step of shredding 3)Easy to operate 4)Easy to maintain 5)No knives to keep sharp 6)Drying effect during operation 7)Separation of FE and non FE – materials 8)Different output fuel particle sizes for main burner and calciner possible

Feed  Product Feed pre-selection No larger carpets No tyres Reduce large solid beams

Proper Pyro-Control with FFB Feeder FFB - Fuel Feeder Burner: Unlike rotary units, this unit: is easy to operate and maintain is easy to take off-line during operation provides air seal by the fuel material itsself so no moving parts can get stuck FFB - Fuel Feeder Burner: The hopper feeds to the burner pipe directly An outer pipe carries coal as 10% control fuel Tertiary air ducted tangentially to control flame

Mjolnir The future of alternative fuels preparation ! One grinding step does everything Do nt worry about feeding in hard foreign objects Throw the resultant fuel directly to burners Correct dosing and injection methods Control pyro-process