Biomass Combustion With Emphasis on Interactions Between Metals and Inorganic Particulate

2005 ◽  
Author(s):  
Fadi Eldabbagh ◽  
Appadurai Ramesh ◽  
Karl K. Rink ◽  
Janusz A. Kozinski
Keyword(s):  
Heavy Metals ◽  
Co2 Emissions ◽  
Inductively Coupled Plasma ◽  
Fossil Fuels ◽  
Analytical Techniques ◽  
Pilot Scale ◽  
Solid Particles ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Inorganic Particles

Biomass is clean, stored solar energy. Not only is it a plentiful fuel, but its use also reestablishes the natural carbon cycle helping mitigate greenhouse gas emissions. This renewable energy source is nearly CO2 neutral. Overall, it is possible to achieve a 93% reduction in net CO2 emissions per unit heating value by switching from coal to biomass and a 84% reduction by switching from natural gas-fired cogeneration to biomass. Due to inherent advantages of the biomass in substituting fossil fuels, and increasing legislative pressures against CO2 emissions (Kyoto Protocol), biomass-based power is genuinely considered. It seems practically impossible to meet Kyoto requirements by replacing fossil fuels combustion with nuclear energy, hydropower or fuel cells. Simply, there is not enough time. In this context, there exists a niche for the biomass-based power generation. This paper compares interactions between metals and solid particles evolving from biomass during the classical Fluidized Bed Combustion (FBC) and a new Low-High-Low temperature (LHL) combustion. Experiments, conducted at a pilot-scale, reveal a clear pattern of surface predominance of light metals (Ca, K) and core predominance of heavy metals (Cd, Cr) within the LHL-generated particles. No such behavior was induced by the classical FBC approach. Metals migration is linked to the evolution of inorganic particles. A composite picture of the metals rearrangements in the particles was obtained by the combination of independent analytical techniques including electron probe microanalysis, field emission scanning electron microscopy, inductively-coupled plasma spectrometry and X-ray diffractometry. It is suggested that the combination of (i) the high-temperature region in the LHL and (ii) changes in the surface free energy of the particles is the driving force for the metal-particle behavior. Important practical implications of the observed phenomena are proposed including removal of hazardous submicron particulate and reduction in fouling/slagging during biomass combustion. These findings may contribute to redesigning currently operating FBC units in order to generate non-hazardous, non-leachable, re-usable particles where heavy metals are immobilized while environmental and technological problems reduced.

Emission fluxes of heavy metals from the fluidized bed combustion of fossil fuels

1995 ◽  
Vol 26 ◽  
pp. S655-S656
Author(s):  
J Smolík ◽  
M Hartman ◽  
I Sýkorová ◽  
J Kučera
Keyword(s):  
Heavy Metals ◽  
Fluidized Bed ◽  
Fossil Fuels ◽  
Fluidized Bed Combustion ◽  
Emission Fluxes

scholarly journals Fluidized Bed Combustion: Technology for Efficient Utilization of Biomass Residues

2018 ◽  
Vol 7 (2) ◽  
pp. 73-79
Author(s):  
Vishal Sharma ◽  
Rajeev Kamal Sharma
Keyword(s):  
Fluidized Bed ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Technical Approach ◽  
Fast Pace ◽  
Combustion Technology ◽  
Alternate Source ◽  
Fluidized Bed Combustor

Fossil fuels are the most common and reliable energy source, which presently fulfill 80% energy requirements all across the world. In the last few decades, over-consumption, fast pace modernization and population growth are some prominent factors which are exploiting the fossil fuels. The degradation of natural resources has gone up at an alarming rate which provoked to look for an alternate source of energy. From all available alternative renewable energy sources, biomass is the only carbon-based sustainable option. But, its diversity makes it a complex and difficult fuel. Among all technologies used for energy generation from the biomass, fluidized bed combustion is emerging as a suitable best option to handle fuel diversity. This article deals with biomass fluidization and its combustion in a fluidized bed. The difficulties encountered during biomass combustion and different solutions for the same have been highlighted. Problems like deposition, corrosion, agglomeration and trace metal emission have been discussed and their remedies to avoid the discontinuity in the operation of biomass-fired fluidized bed combustor. This technical approach will help to reduce environmental problems, improve the economic structure of the nation, and remove obstacles for sustainable energy development.

FB Combustion of a Biomass Fuel: Comparison Between Pilot Scale Experiments and Model Simulations

2003 ◽  
Author(s):  
Francesco Miccio ◽  
Fabrizio Scala ◽  
Riccardo Chirone
Keyword(s):  
Heat Release ◽  
Pilot Scale ◽  
Combustion Efficiency ◽  
Volatile Matter ◽  
High Reactivity ◽  
Operating Conditions ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Bed Temperature ◽  
Carbon Loading

In the present work the efficiency of the fluidized bed combustion of high-volatile fuels and the extent of volatile matter post-combustion in the splashing zone and freeboard are investigated. A typical Mediterranean biomass (pine-seed shells) has been burned in a pilot-scale bubbling FB combustor (200kWt) at different operating conditions. Both over- and under-bed fuel feeding options have been considered. A FBC model specifically developed for high-volatiles fuels has been also applied to provide a comparison with bed carbon loading, in-bed heat release and splashing region temperature experimental data. Experimental results showed that the biomass combustion efficiency is always very high as a consequence of the high reactivity of the fuel. Extensive volatiles post-combustion above the bed is observed, whose extent appears to be sensitive to the over/under bed feeding option and to the excess air. Approximately 80% of the total heat is released/recirculated in the bed, the remainder leading to appreciable overheating of the freeboard with respect to the nominal bed temperature. Very low bed carbon loadings have been found. Model results compare well with the experimental temperature, heat release and carbon loading trends. However, detailed prediction of the freeboard temperature profiles requires further improvements of the model.

Combustion Characteristics of Heavy Liquid Fuels in a Bubbling Fluidized Bed

2002 ◽  
Vol 124 (1) ◽  
pp. 40-46 ◽  
Author(s):  
E. J. Anthony ◽  
D. Y. Lu ◽  
J. Q. Zhang
Keyword(s):  
Heavy Metals ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Liquid Fuel ◽  
Pilot Scale ◽  
Liquid Fuels ◽  
Feeding System ◽  
Fluidized Bed Combustion ◽  
Fuel Flexibility ◽  
Bubbling Fluidized Bed

Liquid fuels such as bitumen, tars, and pitches are byproducts of heavy oil upgrading processes, and are usually contaminated with high sulphur and sometimes heavy metals contents as well. Fluidized bed combustion (FBC) appears to be a promising technology for the combustion of such fuels due to its inherent fuel flexibility and low emissions characteristics. The combustion of three liquid fuels, i.e., no. 6 oil, bitumen and pitch was investigated in a pilot-scale bubbling FBC unit. An efficient liquid fuel feeding system was developed and a bubbling FBC was successfully used to combust all three liquid fuels. The proportion of fuel escaping in the form of unburnt hydrocarbons in the flue gas was less than 0.4 percent and combustion efficiencies higher than 98.5 percent were achieved. However, combustion of liquid fuels tended to occur in the freeboard and, therefore, good mixing of the fuels in the bed was critical in achieving satisfactory combustion performance.

scholarly journals Measuring heavy metal content in bone using portable X-ray fluorescence

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Nicole C. Little ◽  
Victoria Florey ◽  
Irma Molina ◽  
Douglas W. Owsley ◽  
Robert J. Speakman
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Inductively Coupled Plasma ◽  
Analytical Techniques ◽  
Human Populations ◽  
Portable Xrf ◽  
X Ray ◽  
Icp Ms ◽  
Time Required ◽  
Xrf Analyses

The ability of inorganic-based analytical chemistry techniques to quantify trace amounts of heavy metals in skeletal remains has been integral for understanding health and social status in human populations. Low detection limits and the sensitivity of inductively coupled plasma- mass spectrometry (ICP-MS) and other techniques to most elements on the periodic table are ideally suited for the quantification of lead (Pb) and other heavy metals in bone. However, the time required for sample preparation and analysis, expense, destructive analytical process, and availability of instrumentation often limit researchers’ ability to utilise these techniques for archaeological applications. This paper explores the use of portable X-ray fluorescence (XRF) instrumentation for heavy metal analysis of bone as an alternative to more traditional analytical techniques. XRF has been shown to be an extremely useful tool for archaeologists seeking to conduct quantitative analyses of cultural materials such as obsidian and metals. However, little research has been undertaken to assess the usefulness of portable XRF for measuring heavy metals found in low concentrations in archaeological bone. This paper compares data derived from ICP-MS and portable XRF analyses of bone. Results demonstrate that XRF analyses of bone are problematic due to diagenesis and variability of Pb content in bone.

Fluidized Bed Combustion of a Biomass Fuel: Comparison Between Pilot Scale Experiments and Model Simulations

2005 ◽  
Vol 127 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Francesco Miccio ◽  
Fabrizio Scala ◽  
Riccardo Chirone
Keyword(s):  
Heat Release ◽  
Fluidized Bed ◽  
Pilot Scale ◽  
Volatile Matter ◽  
High Reactivity ◽  
Operating Conditions ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Bed Temperature ◽  
Carbon Loading

In the present work the efficiency of the fluidized bed combustion (FBC) of high-volatile fuels and the extent of volatile matter post-combustion in the splashing zone and freeboard are investigated. A typical Mediterranean biomass (pine-seed shells) has been burned in a pilot-scale bubbling FB combustor (200 kWt) at different operating conditions. Both over-and under-bed fuel feeding options have been considered. A FBC model specifically developed for high-volatile fuels has been also applied to provide a comparison with bed carbon loading, in-bed heat release and splashing region temperature experimental data. Experimental results showed that the biomass combustion efficiency is always very high as a consequence of the high reactivity of the fuel. Extensive volatile post-combustion above the bed is observed, whose extent appears to be sensitive to the over/under bed feeding option and to the excess air. Approximately 80% of the total heat is released/recirculated in the bed, the remainder leading to appreciable overheating of the freeboard with respect to the nominal bed temperature. Very low bed carbon loadings have been found. Model results compare well with the experimental temperature, heat release and carbon loading trends. However, a detailed prediction of the freeboard temperature profiles requires further improvements of the model.

scholarly journals Entrained Metal Aerosol Emissions from Air-Fired Biomass and Coal Combustion for Carbon Capture Applications

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1819 ◽  
Author(s):  
Karen Finney ◽  
János Szuhánszki ◽  
Leilani Darvell ◽  
Benjamin Dooley ◽  
Kris Milkowski ◽  
...  
Keyword(s):  
Flue Gas ◽  
Inductively Coupled Plasma ◽  
Carbon Capture ◽  
Optical Emission ◽  
Pilot Scale ◽  
Biomass Energy ◽  
Emission Spectrometry ◽  
Biomass Combustion ◽  
Toxic Heavy Metals ◽  
Aerosol Emissions

Biomass energy with CO2 capture could achieve net negative emissions, vital for meeting carbon budgets and emission targets. However, biomass often has significant quantities of light metals/inorganics that cause issues for boiler operation and downstream processes; including deposition, corrosion, and solvent degradation. This study investigated the pilot-scale combustion of a typical biomass used for power generation (white wood) and assessed the variations in metal aerosol release compared to bituminous coal. Using inductively coupled plasma optical emission spectrometry, it was found that K aerosol levels were significantly greater for biomass than coal, on average 6.5 times, with peaks up to 10 times higher; deposition could thus be more problematic, although Na emissions were only 20% of those for coal. Transition metals were notably less prevalent in the biomass flue gas; with Fe and V release in particular much lower (3–4% of those for coal). Solvent degradation may therefore be less severe for biomass-generated flue gases. Furthermore, aerosol emissions of toxic/heavy metals (As/Cd/Hg) were absent from biomass combustion, with As/Cd also not detected in the coal flue gas. Negligible Cr aerosol concentrations were found for both. Overall, except for K, metal aerosol release from biomass combustion was considerably reduced compared to coal.

Metal-Organic Frameworks vs. Buffers: Case Study of UiO-66 Stability

2020 ◽  
Author(s):  
Daniel Bůžek ◽  
Slavomír Adamec ◽  
Kamil Lang ◽  
Jan Demel
Keyword(s):  
Inductively Coupled Plasma ◽  
Buffer Capacity ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Analytical Techniques ◽  
Aqueous Dispersions ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Metal Organic

<div><p>UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid (HEPES), N-ethylmorpholine (NEM) and phosphate buffer (PB), all of which are commonly used in many UiO-66 applications. High pressure liquid chromatography and inductively coupled plasma mass spectrometry were used to monitor degradation of the MOF. In each buffer, the terephthalate linker was released to some extent, with a more pronounced leaching effect in the saline forms of these buffers. The HEPES buffer was found to be the most benign, whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework. Low concentration TRIS buffers are also recommended, although these offer minimal buffer capacity to adjust pH. Regardless of the buffer used, rapid terephthalate release was observed, indicating that the UiO-66 was attacked immediately after mixing with the buffer. In addition, the dissolution of zirconium, observed in some cases, intensified the UiO-66 decomposition process. These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.</p></div>

Dietary Exposure of Heavy Metals, Minerals and Trace Elements through Cereals Commonly Consumed by Dhaka City Residents

2020 ◽  
Vol 16 (5) ◽  
pp. 815-823
Author(s):  
Md. Bayejid Hosen ◽  
Abu T.M. Abdullah ◽  
Md. Z.H. Howlader ◽  
Yearul Kabir
Keyword(s):  
Heavy Metals ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Industrial Development ◽  
Daily Intake ◽  
Dietary Exposure ◽  
Risk Level ◽  
Dhaka City ◽  
Main Meal ◽  
Minerals And Trace Elements

Background: Contamination of soil and agricultural products by heavy metals resulting from rapid industrial development has caused major concern. Dietary exposure to heavy metals has been associated with toxic and adverse health effects. The main threats to human health from heavy metals are associated with exposure to Pb, Cd and Hg. The aim of this study was to monitor the presence of heavy metals, minerals and trace elements in cereals consumed by Dhaka city residents. Methods: One hundred and sixty cereal samples were collected for eight (08) composited samples and analyzed for the determination of sixteen elements. Heavy metals were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and other elements were determined by Atomic Absorption Spectrometry (AAS). Results: The average concentrations of elements in cereals fall within the safe limit except for Pb, Cr, Na and Mg, which exceeded the safe limits. The daily intake of Cd (23.0 μg), Hg (63.0 μg) and As (13.6 μg) through cereals was below the risk level except for Pb (634.0 μg) and Cr (263.1 μg). The dietary intake of Na (1860.0 mg), Mg (347.0 mg) and Mn (4600.0 μg) exceeded the toxic level while K (829 mg) was below the RDA. Conclusion: As the main meal of average Bangladeshi people is boiled rice served with some vegetables, our findings indicate that the residents of Dhaka city are at risk from Pb and Cr contamination and their dietary need for some important minerals and trace elements is not fulfilled by cereals.

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