Development of a New Sensor Module for an Enhanced Fuel Flexible Operation of Biomass Boilers

The heterogeneity of biogenic fuels, and especially biogenic residues with regard to water and ash content, particle size and particle size distribution is challenging for biomass combustion, and limits fuel flexibility. Online fuel characterization as a part of process control could help to optimize combustion processes, increase fuel flexibility and reduce emissions. In this research article, a concept for a new sensor module is presented and first tests are displayed to show its feasibility. The concept is based on the principle of hot air convective drying. The idea is to pass warm air with 90 °C through a bulk of fuel like wood chips and measure different characteristics such as moisture, temperatures and pressure drop over the bulk material as a function over time. These functions are the basis to draw conclusions and estimate relevant fuel properties. To achieve this goal, a test rig with a volume of 0.038 m3 was set up in the laboratory and a series of tests was performed with different fuels (wood chips, saw dust, wood pellets, residues from forestry, corn cobs and biochar). Further tests were carried out with conditioned fuels with defined water and fines contents. The experiments show that characteristic functions arise over time. The central task for the future will be to assign these functions to specific fuel characteristics. Based on the data, the concept for a software for an automated, data-based fuel detection system was designed

Untersuchung möglicher Umweltauswirkungen bei der Entsorgung nanomaterialhaltiger Abfälle in Abfallbehandlungsanlagen

Derzeit befindet sich eine Vielzahl von Produkten auf dem Markt, die so genannte synthetische Nanomaterialien enthalten. In den kommenden Jahren ist mit einem weiteren Anstieg zu rechnen, wodurch auch vermehrt Abfälle mit einem erhöhten Anteil an Nanomaterialien anfallenwerden. Allerdings ist der Kenntnisstand über den Verbleib von nanomaterialhaltigen Abfällen in der Entsorgungsphase gering. Dies wurde zum Anlass genommen, um innerhalb des Projektes die Emissionspfade bei der thermischen Abfallbehandlung eingehend zu untersuchen

Leaching of Titanium Dioxide Nanomaterials from Agricultural Soil Amended with Sewage Sludge Incineration Ash: Comparison of a Pilot Scale Simulation with Standard Laboratory Column Elution Experiments

Nanoscale titanium dioxide (nTiO2 (Hombikat UV 100 WP)) was applied to sewage sludge that was incinerated in a large-scale waste treatment plant. The incineration ash produced was applied to soil as fertilizer at a realistic rate of 5% and investigated in pilot plant simulations regarding its leaching behavior for nTiO2. In parallel, the applied soil material was subject to standard column leaching (DIN 19528) in order to test the suitability of the standard to predict the leaching of nanoscale contaminants from treated soil material. Relative to the reference material (similar composition but without nTiO2 application before incineration) the test material had a total TiO2 concentration, increased by a factor of two or 3.8 g/kg, respectively. In contrast, the TiO2 concentration in the respective leachates of the simulation experiment differed by a factor of around 25 (maximum 91.24 mg), indicating that the added nTiO2 might be significantly mobilisable. Nanoparticle specific analysis of the leachates (spICP-MS) confirmed this finding. In the standard column elution experiment the released amount of TiO2 in the percolates between test and reference material differed by a factor of 4 to 6. This was also confirmed for the nTiO2 concentrations in the percolates. Results demonstrate that the standard column leaching, developed and validated for leaching prediction of dissolved contaminants, might be also capable to indicate increased mobility of nTiO2 in soil materials. However, experiments with further soils are needed to verify those findings