Arpad B. Palotas

Evaluation of Organometallic Fuel Additives for Soot Suppression

Abstract In this work, we investigate the utility of the smoke lamp for evaluating the soot-reducing potential of additives, by comparing it to a more complex liquid-fed laminar diffusion flame. The additives, ferrocene (bis(cyclopentadienyl) iron-Fe(C5H5)2), ruthenocene (bis(cyclopentadienyl)ruthenium-Ru(C5H5)2), iron naphthenate (a 12% iron salt of naphthenic acid, which is a mixture of fatty carboxylic acids, some of which may include a cyclopentane ring), and MMT (Methylcyclopentadienyl manganese tricarbonyl-CH3C5H4Mn(CO)3) are evaluated at various concentrations in the jet fuel JP-8. Although the smoke lamp is a simple, inexpensive, and widely-available test for evaluating the sooting potential of liquid fuels, it does not provide an effective measure of soot suppression by metal-containing additives. The drop-tube reactor more accurately captures the physical conditions and processes—droplet vaporization, ignition, and rich vs. lean operation—typically found in more complex systems. We find in the smoke lamp that ferrocene, and to a lesser degree ruthenocene, are effective soot suppressors when used in JP-8, and that their effectiveness increases with increasing concentration. In the smoke lamp, MMT and iron naphthenate have minimal effect. On the other hand, in the drop-tube reactor, all four additives are quite effective, especially at fuel lean conditions, where soot suppression reaches 90–95%. Under fuel-rich conditions, where in some cases the additives elevate the yield of soot aerosol slightly, we find a significant increase in the production of the soluble organic fraction of the aerosol, i.e., tar. In order to understand why the smoke lamp sometimes fails to indicate a soot suppressing potential (i.e., from MMT and iron naphthenate), soot samples were collected from a wick lamp burning ferrocene and iron naphthenate additives in JP-8. These samples, as well as several from the drop-tube reactor, were analyzed by X-Ray Fluorescence (XRF) in order to determine their metal content, and we find that the soot aerosol produced by the wick lamp using ferrocene-containing fuel had roughly 30 times the iron content of the soot aerosol produced by the wick lamp using iron-naphthenate-containing fuel. This difference in metal content is not found in samples produced in the drop-tube reactor. We conclude that the poor performance of iron naphthenate in the smoke lamp is likely the result poor vaporization of the additive from the wick, a consequence of its high molecular weight (average 465).

Automated analysis of heterogeneous carbon nanostructures by high-resolution electron microscopy and on-line image processing.

High-resolution electron microscopy is an efficient tool for characterizing heterogeneous nanostructures; however, currently the analysis is a laborious and time-consuming manual process. In order to be able to accurately and robustly quantify heterostructures, one must obtain a statistically high number of micrographs showing images of the appropriate sub-structures. The second step of analysis is usually the application of digital image processing techniques in order to extract meaningful structural descriptors from the acquired images. In this paper it will be shown that by applying on-line image processing and basic machine vision algorithms, it is possible to fully automate the image acquisition step; therefore, the number of acquired images in a given time can be increased drastically without the need for additional human labor. The proposed automation technique works by computing fields of structural descriptors in situ and thus outputs sets of the desired structural descriptors in real-time. The merits of the method are demonstrated by using combustion-generated black carbon samples.

Solubility analysis and disposal options of combustion residues from plants grown on contaminated mining area

Biomass, as a renewable energy source, is an excellent alternative for the partial replacement of fossil fuels in thermal and electric energy production. A new fuel type as biomass for energy utilisation includes ligneous plants with considerable heavy metal content. The combustion process must be controlled during the firing of significant quantities of contaminated biomass grown on brownfield lands. By implementing these measures, air pollution and further soil contamination caused by the disposal of the solid burning residue, the ash, can be prevented. For the test samples from ligneous plants grown on heavy metal-contaminated fields, an ore mine (already closed for 25 years) was chosen. With our focus on the determination of the heavy metal content, we have examined the composition of the soil, the biomass and the combustion by-products (ash, fly ash). Our results confirm that ash resulting from the combustion must be treated as toxic waste and its deposition must take place on hazardous waste disposal sites. Biomass of these characteristics can be burnt in special combustion facility that was equipped with means for the disposal of solid burning residues as well as air pollutants.

Environmentally Sound Combustion of Ligneous Plants Grown in Heavy Metal-Contaminated Soil

The heavy metal contamination of soils and groundwaters is a typical category of toxic pollution deriving from large-scale industrial operations. Excessive metal concentrations commonly occur around abandoned mines and metal processing plants. Several cleanup technologies are known for the removal of pollutants from soil and groundwater systems including surface and subsurface waters. Phytoremediation is a biological treatment method based on the accumulative potential of plants to extract heavy metal contaminants from the ground. The produced biomass should be considered as hazardous waste and treated with special care.

Scanning Transmission Electron Microscopy Analysis of Diesel Soot Particles for Source Attribution

Scanning transmission electron microscopy (STEM) coupled with energy dispersive x-ray analysis (EDX) has been used to characterize the elemental composition of diesel soot samples. The STEM employed in this investigation is the Vacuum Generators Microscope HB603, with a microanalytical resolution approaching 1 nm, allowing the analysis of individual soot particles and aggregates. Quantification of the EDX spectra is accomplished after background and absorption corrections. This information can then be used to pinpoint the fuels and combustion process from which the soot originated. Six diesel soots were analyzed in this study including three from a U.S. Bureau of Mines diesel test engine, two from a West Virginia University diesel test engine, and one from an Orion diesel bus engine. This research showed that soot impurities were found throughout the aggregates, and that only one or two soot particles were necessary to obtain a chemical fingerprint. Some of these elements may be traced to the fuel and lubricant. Other elements were components of the engine itself that combined with the soot particulates during the combustion process. The concept of using a ‘Truth Table’ for the purpose of source attribution is also introduced.

Utilisation of Various Hydro-Carbon-Based Wastes by Thermo-catalytic Conversion

The global need for energy and raw materials is constantly on the rise as mankind’s technology progresses. Due to more and more environmental load and fossil energy carriers exhausted, processes designed for thermo-catalytic conversion of various hydrocarbon-based wastes (plastics- and rubber waste, biomasses) and fuels with a low calorific value (lignite, brown coal) have come into focus in the last decades. The essence of these processes is that solid raw materials forming long carbon chains can be converted at medium-high temperatures (410–450 °C) by means of a special reactor system into more valuable hydrocarbon fractions of liquid and gas state such as petrol-, gas oil-, fuel gas-type products. We examined in our work, how low-quality rubber waste and/or brown coal, plastic waste raw materials can be converted into better quality products—of primarily liquid state. The problem raising a number of open points is a complicated optimisation issue as various heterogeneous components and their content in aggressive contaminants (sulphur, chlorine, nitrogen, oxygen, oxides, carbonates etc.) can largely affect decomposition kinetics thus the quality and quantity of hydrocarbon products formed so as well. This publication covers the system modelling techniques in detail that can be used as a foundation for the basis of mathematical modelling of high-complexity technical systems.

Investigation of Tyre Recycling Possibilities with Cracking Process

The field of vehicle tyres is a key pillar to the Vehicle Engineering BSc launched in September 2016 at the Faculty of Mechanical Engineering and Informatics of the University of Miskolc and the Tyre manufacturing postgraduate course in the technological specialisation on which work is in progress. Generating a yearly amount of several 100 millions of tyres as waste of the automotive industry is, almost 80% of them as passenger car tyres and 20% as truck tyres, whose management creates a huge load to bear on society. These days a relevant task of this field is to find a solution that is reducing environmental loads and sustainable to the solution. Vehicle tyres contain many organic and inorganic compounds: natural and artificial caoutchoucs (NR, SBR, BR, IIR, EPDM), silica, zinc oxide, sulphur, steel and artificial fibres, anti-ageing agents, carbon black etc. whose production requires a significant use of fossil energy carriers. There are several ways of recycling tyres lost their original function: incineration, recycling in its material (rubber-based pavements, roads, sporting grounds) or chemical conversion (energy carrier, chemical raw material), respectively. These days cracking in combined material flow embodies one of the main research directions of chemical conversion. The bottom line is that several raw materials are decomposed in parallel during catalyst-assisted thermal cracking: blends of different ratios of biomass, plastics, rubber tyre. This publication presents options of chemical conversion and its optimisable parameters. We investigated thermo-catalytic thermal cracking (cracking) of rubber and polystyrene waste producing thereby valuable petrol- and gas oil-type hydrocarbon products.

Investigation of natural gas theft by magnetic remanence mapping

Natural gas theft causes major losses in the energy industry in Hungary. Among the non-technical losses occurring in natural gas networks, fraudulent residential consumption is one of the main factors. Up to 2014, gas meters that are most widely used in residential monitoring are manufactured with ferromagnetic moving components, which makes it possible to alter or disrupt the operation of the meters non-intrusively by placing permanent magnets on the casing of the meters. Magnetic remanence mapping was used to investigate a sample of 80 recalled residential meters and detect potentially fraudulent activity. 10% of the meters were found suspect by magnetic remanence measurement, of which 50% were confirmed to be potentially hijacked by further mechanical investigation. The details of the technique are described in this paper, along with experimental results and the discussion of the analysis of the real-world samples.

Diagnostic Method for the Determination of Refractory Lining Thickness of High Temperature Equipment

Refractory wall of high temperature equipment used in industry pl a s an important role in technological processes. Abrasive forces, chemical corros i n, effecting on internal working refractory materials, thermal and mechanical stresses during operation cause the fast and unequal thinning down in certain areas of the lining of the industrial furnaces. The heat loss and the wall thickness are in direct relationship. Une xpect d holes of the unevenly thinned refractory wall of hot metal pig iron mixer pose an especi ally big danger since the leaking pig iron and slag can cause operating trouble, explosion, fire or tragic acci dents. Safe operation of furnaces of molten materials and increase of th ir lifetime can be achieved by regular – in operation – repair of the quickly wearing wall parts. The thickness of a steel plant pig iron mixer’s lining can not be observed visually during operation there fore the timing and the area of repair is usually determined by local experience based on the wall’s outside temp rature. Primary goal of our research is the elaboration of a diagnost ic method for the determination of the critically thinned down of refractory lining. In order to examine the actual wall thickness of hot metal mix ers, thermovision is applied at DUNAFERR Steel Plants Ltd. The repairing details of the ref ractory wall are determined on the basis of the temperature distribution at the outside armor plate of he urnace. Results of the industrial experience accumulated in the course of mixer wall re pair are shown. The correct estimation of the smallest wall thickness of furnace is expec ted as a result of coupling thermovision with finite element modeling of the heat transport processes. The diagnostic method and the diagram resulting from the simulation can be directly used in the industrial expe rience.