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Chemical composition and properties of ashes from combustion plants using Miscanthus as fuel

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Journal of Environmental Sciences 2017年第4期29卷 178-183页

作者： christof Lanzerstorfer School of Engineering/Environmental Sciences University of Applied Sciences Upper Austria A-4600 Wels Austria

Miscanthus giganteus is one of the energy crops considered to show potential for a substantial contribution to sustainable energy production. In the literature there is little data available about the chemical composition of ashes from the combustion of Miscanthus and practically no data about their physical properties. However, for handling, treatment and utilization of the ashes this information is important. In this study ashes from two biomass combustion plants using Miscanthus as fuel were investigated. The density of the ashes was 2230 ± 35 kg/m;, which was similar to the density of ashes from straw combustion. Also the bulk densities were close to those reported for straw ashes. The flowability of the ashes was a little worse than the flowability of ashes from wood combustion. The measured heavy metal concentrations were below the usual limits for utilization of the ashes as soil conditioner. The concentrations in the bottom ash were similar to those reported for ash from forest residue combustion plants. In comparison with cyclone fly ashes from forest residue combustion the measured heavy metal concentrations in the cyclone fly ash were considerably lower. Cl-, S and Zn were enriched in the cyclone fly ash which is also known for ashes from wood combustion. In comparison with literature data obtained from Miscanthus plant material the concentrations of K, Cl-and S were *** can be attributed to the fact that the finest fly ash is not collected by the cyclone de-dusting system of the Miscanthus combustion plants.

关键词： Biomass combustion Miscanthus Ash composition Ash properties

Chemical composition and physical properties of filter fly ashes from eight grate-fired biomass combustion plants

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Journal of Environmental Sciences 2015年第4期27卷 191-197页

作者： christof Lanzerstorfer School of Engineering and Environmental Sciences University of Applied Sciences Upper Austria

For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass combustion plants were investigated. In fly ash from straw combustion high concentrations of（K） were found, whereas in the fly ash from wood combustion the concentrations of Ca and Mg were higher. The average concentration of PO3-4was similar in both types of fly ashes. In all wood fly ashes some measured heavy metal concentrations were above the limits for utilization. The straw fly ashes were much less contaminated and can be utilized. For wood fly ash most parameters showed little variation, except from one fly ash where the dust pre-separator is in poor condition. The average values were： mass median diameter 4.3 ± 0.8 μm, spread of particle size distribution19 ± 11, particle density 2620 ± 80 kg/m^3 and angle of repose 50°± 1°. The density of the straw fly ashes is lower（2260 ± 80 kg/m^3） and the spread of the size distribution is higher（72 ± 24）.For one straw combustion fly ash the values of the mass median diameter and the angle of repose were similar to the values of wood combustion fly ash, for the other straw fly ash the values differed considerably. While the particle size of this fly ash was much smaller,surprisingly the angle of repose was also lower. This can be attributed to the formation of small agglomerates in this fly ash, which were not disintegrated without a certain stress.

关键词： Biomass combustion Filter fly ash Chemical analysis Physical properties

Flowability of various dusts collected from secondary copper smelter off-gas

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Particuology 2016年第2期14卷 68-71页

作者： christof Lanzerstorfer University of Applied Sciences Upper Austria School of Engineering/Environmental Sciences Stelzhamerstraβe 23 A-4600 Wels Austria

Stable flow of off-gas dust from dust collector hoppers and storage silos is important for smooth operation. Flow properties of the collected off-gas dust are critical to achieve suitable flow. Various dust samples collected from secondary copper smelter off-gases were studied. The median diameter of the fine-grained dusts varied from 0.8 to 1.4 μm and the flowability ranged from ＂cohesive＂ to ＂very cohesive＂. The flowa- bility of shaft and anode furnace dust improved slightly with increasing consolidation stress and their wall friction angles decreased, which is a typical behavior. In contrast, the flowability of converter dust decreased with increasing consolidation stress and its wall friction angles increased. Pre-shear treatment of converter dust worsened its flowability, increased the wall friction angle, and improved the flowabil- ity with increasing consolidation stress. This is believed to occur because pre-shear treatment fragments small agglomerates in the dust that improve flowability. The presence of such agglomerates was con- firmed by sieving tests. A diagrammatic representation of the flowability showing that the unconfined yield strength is dependent on consolidation stress can be improved by using logarithmically scaled axes.

关键词： Copper smelter Dust Flowability Shear test

Experimental study on influence of blade angle and particle size on particle mechanics on a batch-operated single floor of a multiple hearth furnace

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Particuology 2024年第2期85卷 224-240页

作者： Max Kriegeskorte Nikoline Hilse Phil spatz Viktor Scherer Institute for Energy Plant Technology(LEAT) Ruhr University BochumUniversitätsstraβe 15044780 BochumGermany

In industry,multiple hearth furnaces are used for the thermal treatment of particulate *** current contribution concentrates on the experimental analysis of particle mechanics for a batch-operated single floor of a multiple hearth *** particles are agitated on the circular floor by a single,rotating rabble arm equipped with three flat rabble blades of 10 mm *** blade angle,defined as the angle,which the blade is inclined against the tangential direction,is varied from 0°to 90°.A single layer of spherical polyoxymethylene(POM)particles with three different diameters(5,10 and 20 mm)is placed on the *** analyze the results,two parameters have been extracted from image analysis when the bed of particles is agitated,first,the area not covered by particles and second,the frequency distribution of the mean distance among the *** particle free surface area increases with the inclination of the *** evolution of the particle free surface area differs for the different particle *** general,the maximum particle free area for all blade angles is the largest for the 5 mm particles followed by the 20 mm *** the 10 mm particles,the particle free surface area starts for a blade angle of 0°at larger values than for the 20 mm particles but the values fall below the values for the 20 mm particles for larger blade *** reason for this behavior is discussed in *** mean distance among the particles is a parameter characterizing the length scales dominating the effects on the *** frequency distribution of the mean distance among particles provides infor-mation about the morphology of the particle bulk,for example,whether the free surface area is inter-spersed with particles.

关键词： Hearth furnace floor Particle movement Spherical particles Particle free surface area Mean distance among particles

Hierarchical assemblies of molecular frameworks—MOF-on-MOF epitaxial heterostructures

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Nano Research 2021年第2期14卷 355-368页

作者： Ritesh Haidar christof Woll Institute of Functional Interfaces(IFG) Karlsruhe Institute of Technology(KIT)Hermann-von-Helmholtz-Platz176344 Eggenstein-LeopoldshafenGermany

Functional,porous metal-organic frameworks(MOFs)have attracted much attention as a very flexible class of crystalline,porous *** more advanced applications that exploit photophysical properties,the fabrication of hierarchical assemblies,including the creation of MOF/MOF heterointerfaces,is *** the manufacturing of superstructures with length scales well beyond that of the MOF pore size,layer-by-layer(Ibl)methods are particularly *** allow the isoreticular approach to be extended to superstructures with micrometer length scales,a range that is not accessible using conventional MOF *** Ibl approach further substantially extends the compositional diversity in *** the same time,the favorable elastic properties of MOFs allow for heteroepitaxial growth,even in the case of lattice misfits as large as 20%.While the MOF-on-MOF approach to designing multicomponent superstructures with synergistic multifunctionality can also be realized with sophisticated solvothermal synthesis schemes,the Ibl(or liquid-phase epitaxy)approach carries substantial advantages,in particular when it comes to the integration of such MOF superstructures into optical or electronic *** the structure vertical to the substrate can be adjusted using the Ibl method,photolithographic methods can be used for lateral *** this review,we will discuss the Ibl liquid-phase epitaxy approach to growing surface-anchored MOF thins films(SURMOFs)as well as other relevant one-pot synthesis methods for constructing such hierarchically designed structures and their emerging applications.

关键词： metal-organic framework(MOF)heterostaicture hierarchical assembly epitaxy layer-by-layer growth surface-anchored MOFs

Confidential computing and related technologies:a critical review

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Cybersecurity 2023年第4期6卷 26-32页

作者： Muhammad Usama Sardar christof Fetzer Faculty of Computer Science Technische Universität DresdenDresdenGermany

This research critically reviews the definition of confidential computing(CC)and the security comparison of CC with other related technologies by the Confidential Computing Consortium(CCC).We demonstrate that the definitions by CCC are ambiguous,incomplete and even *** also demonstrate that the security comparison of CC with other technologies is neither scientific nor *** highlight the issues in the definitions and comparisons and provide initial recommendations for fixing the *** recommendations are the first step towards more precise definitions and reliable comparisons in the future.

关键词： Confidential Computing(CC) Trusted Execution Environment(TEE) Homomorphic Encryption(HE) Trusted Platform Module(TPM) Formal methods

Leaching of the residue from the dry off-gas de-dusting and desulfurization process of an iron ore sinter plant

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 116-121页

作者： christof Lanzerstorfer Qi Xu Robert Neuhold School of Engineering/Environmental Sciences University of Applied Sciences Upper Austria Siemens VAI Metals Technologies GmbH

The residue from a second-stage dry sinter plant off-gas cleaning process contains both the fine dust from the sinter plant and the sorbent used. Recycling of the material that is usually handled by landfills to the sinter plant feed is not possible because of its chloride con- tent. Leaching of the chlorides allow the recycling of remaining solids. The saline leachate produced contains some heavy metals and must be treated before it is discharged into the sea. In laboratory experiments, leaching tests with the subsequent treatment of the leachate were con- ducted. After the process was optimized, all heavy-metal concentrations were below the permissible values. The optimum treatment condi- tions for heavy-metal precipitation were observed to be the filtration of the suspended solids followed by the dosing of liquid with lime milk （pH 10） and the subsequent precipitation using sodium sulfide.

关键词： heavy metals off-gas cleaning recycling residues leaching sinter plants

Monitoring spatiotemporal soil moisture changes in the subsurface of forest sites using electrical resistivity tomography (ERT)

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Journal of Forestry Research 2022年第5期33卷 1649-1662页

作者： Julian Fäth Julius Kunz christof Kneisel Institute of Geography and Geology University of WürzburgAm Hubland97074 WürzburgGermany

The effects of drought on tree mortality at forest stands are not completely understood. For assessing their water supply, knowledge of the small-scale distribution of soil moisture as well as its temporal changes is a key issue in an era of climate change. However, traditional methods like taking soil samples or installing data loggers solely collect parameters of a single point or of a small soil volume. Electrical resistivity tomography (ERT) is a suitable method for monitoring soil moisture changes and has rarely been used in forests. This method was applied at two forest sites in Bavaria, Germany to obtain high-resolution data of temporal soil moisture variations. Geoelectrical measurements (2D and 3D) were conducted at both sites over several years (2015-2018/2020) and compared with soil moisture data (matric potential or volumetric water content) for the monitoring plots. The greatest variations in resistivity values that highly correlate with soil moisture data were found in the main rooting zone. Using the ERT data, temporal trends could be tracked in several dimensions, such as the interannual increase in the depth of influence from drought events and their duration, as well as rising resistivity values going along with decreasing soil moisture. The results reveal that resistivity changes are a good proxy for seasonal and interannual soil moisture variations. Therefore, 2D- and 3D-ERT are recommended as comparatively non-laborious methods for small-spatial scale monitoring of soil moisture changes in the main rooting zone and the underlying subsurface of forested sites. Higher spatial and temporal resolution allows a better understanding of the water supply for trees, especially in times of drought.

关键词： Geoelectrical monitoring Forest ecology Hydrology Soil water content

Analogies between medusa and single port surgery in gastroenterology and hepatology:A review

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World Journal of Gastroenterology 2021年第47期27卷 8058-8068页

作者： christof Mittermair Helmut G Weiss Department of General Surgery SJOG HospitalSalzburg 5010Austria

Single port surgery(SPS)was introduced as an attractive,minimally invasive surgical technique that ensures esthetic results for many types of visceral ***,surgeons immediately set about performing SPS without preliminary knowledge or training,which resulted in higher complication ***,current studies conclusively show that SPS is scientifically rehabilitated and indicated for simple and complex laparoscopic *** here describe the astonishing analogies between Greek mythology and modern surgery.

关键词： Gastroenterology Single port surgery Surgical technique Surgical complication Gastric or intragastric resections