The DGA MBT Mechanical Bio-Treatment System

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1 DGA Co Ltd present The DGA MBT Mechanical Bio-Treatment System

2 Many systems use membranes to let water vapour out and to prevent water entering a warm compost pile. Most of the moisture is removed within 20 days leaving c. 20% moisture in the end product CONVENIENT OR ENVIRONMENT FRIENDLY At DGA, We believe that there are better more efficient systems for producing power and energy from waste than the well proven convenient system which is practiced by most large scale WTE manufacturers around the world. Inevitably these systems have developed around centres of affluent population, ie European and American cities who would suffer very large scale pollution from Waste if is not managed properly. The result is the Convenient WTE system has been developed essentially as a clean alternative to Landfill, which is at last recognised as a poor waste management system. The Convenient system takes in waste as collected, does the minimum of sorting, extracting mainly material by size as it will not fit the furnace and perhaps value, ie can it be sold?, then delivers to the WTE plant which consumes the waste as fuel, albeit not very efficient fuel. The waste is in effect disappeared without any inconvenience to the population and local government. The Carbon emissons from a wet fuel are higher than from a dry fuel for the same power output.

3 MAKES MORE POWER THAN THE CONVENIENT SYSTEM? What makes the convenient system inefficient? Fortunately we live on a wet planet so water is normally an abundant commodity, including in our waste streams. Water is not combustible and has a major negative effect on any solid fuel, reducing the efficiency with which it can be burned until it requires a high heat value support fuel, such as oil, just to sustain combustion. The most efficient system burn all fuels with the minimum of water, in other words a dry fuel is much more efficient than a wet one. DGA s solution is to employ Natures method of drying wet material ie by aerobic composting as part of a Mechanical Bio Treatment (MBT) system. We select proven technology for sizing and separating of the waste to precise specifications to ensure the RDF is of first quality, and at the same time separating off the organic fraction as a sized material for which the bio drying is available from any number of companies who have skills and specialist in aerobic composting of waste. This low energy system provides a dry, odourless material that is easily handled, easy to refine and safe to handle to make either organic compost, or a dry biomass style fuel. From DGA s perspective it also makes a more usable fuel from raw waste, allowing a storable higher calorific value fuel to be produced rather than feeding the waste to the inefficient Convenient plants. The MBT system allows a fuel to be produced capable of being fired on lower cost equipment normally used for Biomass power, and capable of producing up to 15% more energy from the delivered waste. Of course being derived from waste material the flue gas will be contaminated and require flue gas scrubbing equipment. This must of course comply with the local regulations and these should be based on the EUWID levels of emissions. The flue gas scrubbing plant can be supplied by DGA

4 MEMBRANE DEPLOYED MEMBRANE FASTENINGS AIR INJECTED UNDER THE PILE THROUGH SPECIAL SHAPED FLOOR. A TYPICAL COMPOST PILE

5 The wet biomass residue from the RDF Processing plant will be treated by a Bio-Drying system in an identical way The compost system can convert wet MSW to a relatively dry, odourless easily handled material.

6 Each bay is fitted with an Air blower and a membrane cover to retain heat Typical Facility can be roofed as shown but use of membrane allows composting to be more effective in the open air

7 The membrane material is a key component of The compost technology These picture show the wet biomass reject from the RDF process now stacked in compost rows.

8 Single machine can be used on many bays Typical style of machine For installing the membrane

9 Membrane covers installed and secured Commence drying

10 Temperature measurement in each Pile. Monitored during drying Period

11 Covers off! To reveal a dry odour free material

12 The biomass reject is now a high LCV fuel capable of firing a typical Biomass boiler up to 20 MWe capacity. As the fuel is contaminated in must be fired in a plant with appropriate Scrubbers to keep emissions to EU levels after all it is still waste!

13 PICKING STATION OFFICE Performance\ Waste Delivery 1000 tn/day RDF Manufacture 350 tn/day Recyclable c 10% Reject c 10% Biomass Reject c 500 tn/day Biomass Moisture c 70% Biomass MC after dry c 30% Biomass Reduce to 195 tn/day WASTE DELIVERY RDF EXPORT Potential Power Production from 1000 tn/day - 20 MWe gross + 10 MWe RDF sold If 3 PP supplied 30 MWe DGA Eco Waste Plants with a complete MBT plant by Lindner to produce RDF and high quality dry biomass waste fuel

14 Conclusion based on handling 1000 tn/day of waste The MBT system is integrated into the Eco Waste Plants with RDF preparation plant The plant is operating on the high LCV RDF fraction recovered from the waste First step is separation of the Biomass from the RDF process, removing most Moisture with the biomass Collect the Biomass in daily batches and place in a single Bio-Dry bay Quantity based on plant size, typically half waste delivered so 500 tn/day for 1000 tn/day plant Biomass contains c 70% Moisture or MC, ie nearly 2.5 x the dry matter content! Commence drying and hold daily batches for 3 weeks Check MC in piles, if down to <30% MC drying complete Quantity of Biomass after drying estimated at 380 tn/day, water quantity removed 120 tn/day Now dry biomass can be stored awaiting demand from boilers. Note the Heat Value or LCV is comparable to the RDF Plant can reduce the reliance on RDF and switch to just dry Biomass, or if another Eco Plant steam is available, increase the generation capacity to 20 Mwe. The RDF can be sold to the Cement manufacturers. Alternatively a 3rd DGA Eco Plant power line added to further increase the capacity to 30 MWe

15 Thank you!