Muegge Electronic

Scientific objectives and approach: The main innovation of the project is the combination of sludge drying and gasification in one unit having both steps heated up by microwave. The project will develop a basic understanding of the dynamic processes involved in heat transfer and antenna interaction of microwave and the aerodynamic control of flows within the dryer cavity. One specific innovative step required is the design of a novel antenna, using arial technique configuration to achieve sufficient microwave energy density and homogeneity across the conveyed pellet stream to achieve 95% dryness at stage 1 because the gasification process at stage 2 needs dry input of >92%. Problems to be solved: With the increasing population densities within the EU and the predicted rise in the volume of sewage sludge to 10 Bn tonnes p.a., there is an urgent need to provide the 40,000 waste water treatment plants with a cost effective and energy efficient method of converting their biologically active sludge output into an inert form, on-site prior to it's transportation and in a safe form for landfill. European emission standards for disposal [8] and incineration [9] have to be met. There is a need for reduction of hazardous, biologically active sludge being land filled and potentially contaminating ground water supplies for drinking water. Sludge is transported from sewage plants to the incineration with a content of only 30% dry substance (DS). 1.15 M tonnes of DS means actually 3.83 M tonnes p.a. of sludge being transported. This equates to 191,500 truck loads of 20 tonnes each. Expected Impacts: This project delivers the development of a compact and therefor mobile combined sludge drying and gasification system that uses microwave energy to improve the thermal efficiency of both drying and gasification processes and produces waste solid in an inert form. These systems can process up to 1.7 tons per hour of sludge (approx. 0.6 tons/h dry solids content) and achieves 95% drying prior to gasification to produce 'clean' combustible gas supply during gasification stage. A electrical conversion efficiency of 25% will enable to produce sufficient power for the microwave generator. The recovery of 90% of thermal energy from the gases and degassed product and its use during the drying process will enable the system to be energy self-sufficient. Objectives are to substitute at least 20% of the current 1.15M tonnes p.a. European incinerated sludge disposal market within 5 years, generating 23 M p.a. and securing 153 jobs as well as capturing at least 5% of the current 6.8 M tonnes p.a. of the landfill sludge disposal market, generating 34 M p.a., creating 227 jobs. Through this reduction of 230,000 tonnes p.a. of sludge being transported by road and incinerated a lot of transport and up to 19 Mio litres of diesel fuel for transportation can be saved. Apart from that it means the reduction of 340,000 tonnes p.a. of hazardous, biologically active sludge being land filled and potentially contaminating ground water supplies for drinking water.