DescriptionThe objective of biomass incinerators is the generation of electric power by burning organic material, such as wood chips, pellets or bark. During the incineration process the organic input material is decomposed and mostly transformed into gaseous components, while inorganic material remains as solid ash. Bottom ash is the coarse residue which is collected at the bottom of the incinerator. Smaller ash particles can leave the incinerator and are collected as fly ash in gas cleaning filter. Since the ash contains valuable elements like Ca, K, Mg it is reasonable to recycle it to the ground where the biomass was grown, however the concentration of harmful heavy metals has to be under certain limit values given by legislation; limit concentrations for the most common elements are prescrived in the recommendation of the ministry for Agriculture “The use of plant-ashes on fields and grassland” from 1998. For monitoring the metal amounts of ashes intended to be used in agriculture a fast and reliable method is mandatory which allows the qualitative and quantitative determination even at trace levels. ICP-OES was chosen since it offers many advantages for the given analytical task. An analytical method consisting of an acidic microwave assisted digestion prior to the ICP-OES measurement was optimized for ashes from biomass incinerators. The elements of interest were As, Zn, Sb, Pb, Ni, Co, Cd, B, Mn, Fe, Cr, Mg, Al, V, Cu, Ti, Sr and, Ba. A validation including the following parameters was performed for each analyte: limit of determination, limit of quantification, recovery by spiking experiments, accuracy by analysing a certified reference material, wihtin-day-, day-to-day- as well as week-to-week-reproducibility, linearity, and uncertainty of measurement. The method optimized allows the determination of all elements covered by the above mentioned regulation and represents thus an appropriate tool for monitoring flyh ashes.
|Period||13 Oct 2008|
|Event title||XIXth Slovak - Czech Spectroscopic Conference|