scholarly journals Comparative study of a vitrinite-rich and an inertinite-rich Witbank coal (South Africa) using pyrolysis-gas chromatography

2019 ◽  
Vol 6 (4) ◽  
pp. 621-632
Author(s):  
Ofentse M. Moroeng ◽  
Vimbai Mhuka ◽  
Mathew M. Nindi ◽  
R. James Roberts ◽  
Nicola J. Wagner
Keyword(s):  
Bituminous Coal ◽  
Mineral Matter ◽  
Common Source ◽  
Gas Chromatograph ◽  
Geologic History ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Molecular Chemistry ◽  
Polycyclic Aromatic ◽  
The Impact

Abstract This study aims to compare iso-rank vitrinite-rich and inertinite-rich coal samples to understand the impact of coal-forming processes on pyrolysis chemistry. A medium rank C bituminous coal was density-fractionated to create a vitrinite-rich and an inertinite-rich sub-sample. The vitrinite-rich sample has 83 vol% total vitrinite (mineral-matter-free basis), whereas the inertinite-rich counterpart has 66 vol% total inertinite. The vitrinite-rich sample is dominated by collotelinite and collodetrinite. Fusinite, semifusinite, and inertodetrinite are the main macerals of the inertinite-rich sample. Molecular chemistry was assessed using a pyrolysis gas chromatograph (py-GC) equipped with a thermal desorption unit coupled to a time of flight mass spectrometer (MS) (py-GC/MS) and solid-state nuclear magnetic resonance (13C CP-MAS SS NMR). The pyrolysis products of the coal samples are generally similar, comprised of low and high molecular weight alkanes, alkylbenzenes, alkylphenols, and alkyl-subtituted polycyclic aromatic hydrocarbons, although the vitrinite-rich sample is chemically more diverse. The lack of diversity exhibited by the inertinite-rich sample upon pyrolysis may be interpreted to suggest that major components were heated in their geologic history. Based on the 13C CP-MAS SS NMR analysis, the inertinite-rich sample has a greater fraction of phenolics, reflected in the py-GC/MS results as substituted and unsubstituted derivatives. The greater abundance of phenolics for the inertinite-rich sample may suggest a fire-related origin for the dominant macerals of this sample. The C2-alkylbenzene isomers (p-xylene and o-xylene) were detected in the pyrolysis products for the vitrinite-rich and inertinite-rich samples, though more abundant in the former. The presence of these in both samples likely reflects common source vegetation for the dominant vitrinite and inertinite macerals.

scholarly journals PV Waste Thermal Treatment According to the Circular Economy Concept

2020 ◽  
Vol 12 (24) ◽  
pp. 10562
Author(s):  
Magdalena Bogacka ◽  
Martyna Potempa ◽  
Bartłomiej Milewicz ◽  
Dariusz Lewandowski ◽  
Krzysztof Pikoń ◽  
...  
Keyword(s):  
Life Cycle ◽  
Separation Efficiency ◽  
Green Technology ◽  
Photovoltaic Module ◽  
Pyrolysis Products ◽  
Material Recycling ◽  
Polycyclic Aromatic ◽  
Gaseous Fraction ◽  
The Impact ◽  
Research Show

Photovoltaic panels (PV) are one of the most popular technological solutions used to produce green renewable energy. They are known as green technology, but by analyzing a life cycle of a common panel, we can find out that production of these panels is strictly associated with generation of a large waste stream. PV modules are constantly modified and, therefore, it is required to consider the impact of the applied materials on the environment during the whole lifecycle of the product. The most important aspect of the assessment of a life cycle of a photovoltaic module in the phase of decommissioning is material recycling. The process of material recycling is very difficult, due to the lamination used in the currently exploited technology. This paper presents the results of pyrolysis for a sample of a silicon module. The results of the presented research show a weight loss of 48.16 in case of the tested samples. This paper presents the outcome of a quantitative analysis of the content of polycyclic aromatic for liquid and concentrations of Br, Cl and F for a gaseous fraction of pyrolysis products. The goal of the research presented in the paper was to find the optimal parameters for thermal separation, as well as the influence of the energy consumption and materials separation efficiency on the final thermal efficiency of the process.

scholarly journals Impact of CO2 on Pyrolysis Products of Bituminous Coal and Platanus Sawdust

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1370 ◽  
Author(s):  
Ying Luo ◽  
Haoxi Ben ◽  
Zhihong Wu ◽  
Kai Nie ◽  
Guangting Han ◽  
...  
Keyword(s):  
Specific Surface ◽  
Bituminous Coal ◽  
Hydroxyl Groups ◽  
High Porosity ◽  
Pyrolysis Oil ◽  
Biomass Pyrolysis ◽  
Element Analysis ◽  
Pyrolysis Products ◽  
Pyrolysis Oils ◽  
The Impact

Abundant studies have been completed about factors on the pyrolysis of coal and biomass. However, few articles laid emphasis on using CO2 as a carrier gas to explore the compositional changes of pyrolysis products in coal and biomass pyrolysis for industrial application and commercial value. The experiments on coal and biomass pyrolysis in N2 and CO2 using a horizontal tube furnace were conducted at 500 °C. The impact of introducing CO2 on the pyrolysis process of bituminous coal and Platanus sawdust was investigated. The nuclear magnetic resonance (NMR) spectra of tar and the characterizations of char including Brunner-Emmet-Teller (BET) measurements, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, and element analysis were studied. The findings in light of the experimental results show that introducing CO2 enhances the coal and biomass pyrolysis in a solid product by promoting the fracture of hydroxyl groups. It also promotes tar decomposition and the release of volatiles, which contribute to the occurrence of char with high porosity, pore volume, and specific surface. Furthermore, higher specific surface enhances the adsorption performance of char as active carbon. Simultaneously, CO2 promotes the increase of oxygen-containing aromatics especially the methoxy-containing aromatics, and the decrease of deoxygenated aromatic hydrocarbons in pyrolysis oils. In addition, the introduction of CO2 changes the amount of aliphatic compounds in various ways for the pyrolysis of coal and biomass. From a perspective of business, the changes in the composition of pyrolysis oil brought by CO2 may create new value for fuel utilization and industrial products.

scholarly journals Study of Thermal Behavior of Moxa Floss Using Thermogravimetric and Pyrolysis-GC/MS Analyses

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Min Yee Lim ◽  
Xinyue Zhang ◽  
Jian Huang ◽  
Liang Liu ◽  
Yutang Liu ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Aromatic Hydrocarbons ◽  
Ignition Temperature ◽  
Herbaceous Plants ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Polycyclic Aromatic ◽  
Treatment Safety ◽  
Weight Decrease ◽  
Moxa Floss

Moxa floss is a type of biomass used as the main combustion material in moxibustion, a therapy that applies heat from moxa floss combustion to points or body areas for treatment. Safety concerns regarding moxa smoke have been raised in recent years. Since moxa floss is the source material in moxibustion, its thermal behavior and pyrolysis products would be related to the products formed in moxa smoke. This work aims to understand the thermal behavior of moxa floss and investigate the pyrolysis products generated from moxa floss combustion. Six commercial moxa floss samples of 3 storage years and 10 storage years, and of low, medium, and high ratios, were selected. The kinetic data from moxa floss combustion was carried out by a thermogravimetric analyzer. Pyrolysis-gas chromatography and mass spectroscopy using a gas chromatograph and mass spectrometer equipped with a pyroprobe were used to examine the pyrolysis products. Thermogravimetric profiles for all the samples were overall similar and showed a monotonic weight decrease. The range of intensive reaction temperature occurred between 150°C and 450°C, which was characterized by a major weight loss and accompanied by an exothermal degradation of the main components. The average ignition temperature for the samples of 3 and 10 storage years was 218.3°C and 222.6°C, respectively, which was lower than most herbaceous plants. The identified pyrolysis products include monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, ketones, acids, and alkanes. All were of relatively low intensities of below 5% in relative abundance. No volatiles were detected in the samples of 10 storage years. The relatively low values of ignition temperature suggested that moxa floss is more combustible and can be ignited more easily than other herbaceous plants. This may explain why moxa floss has remained as the preferred material used for moxibustion over the years.

Potential Contribution of Nutrients and Polycyclic Aromatic Hydrocarbons from the Creeks of Cootes Paradise Marsh

1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry
Keyword(s):  
Aromatic Hydrocarbons ◽  
Laboratory Experiments ◽  
Dry Weight ◽  
Common Source ◽  
Potential Contribution ◽  
Nitrogen And Phosphorus ◽  
Engine Combustion ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Derivatives Of

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.

scholarly journals Impact of the Wind Turbine on the Parameters of the Electricity Supply to an Agricultural Farm

2021 ◽  
Vol 13 (13) ◽  
pp. 7279
Author(s):  
Zbigniew Skibko ◽  
Magdalena Tymińska ◽  
Wacław Romaniuk ◽  
Andrzej Borusiewicz
Keyword(s):  
Power Plant ◽  
Wind Turbine ◽  
Wind Power ◽  
Rural Areas ◽  
Power Plants ◽  
Reactive Power ◽  
Supply Voltage ◽  
Common Source ◽  
Voltage Fluctuations ◽  
The Impact

Wind power plants are an increasingly common source of electricity located in rural areas. As a result of the high variability of wind power, and thus the generated power, these sources should be classified as unstable sources. In this paper, the authors attempted to determine the impact of wind turbine operation on the parameters of electricity supplied to farms located near the source. As a result of the conducted field tests, variability courses of the basic parameters describing the supply voltage were obtained. The influence of power plant variability on the values of voltage, frequency, and voltage distortion factor was determined. To estimate the capacity of the transmission lines, the reactive power produced in the power plant and its effect on the value of the power factor were determined. The conducted research and analysis showed that the wind power plant significantly influences voltage fluctuations in its immediate vicinity (the maximum value registered was close to 2%, while the value required by law was 2.5%). Although all the recorded values are within limits specified by the current regulations (e.g., the THD value is four times lower than the required value), wind turbines may cause incorrect operation of loads connected nearby. This applies mainly to cases where consumers sensitive to voltage fluctuations are installed in the direct vicinity of the power plant.

scholarly journals Review on Sublethal Effects of Environmental Contaminants in Honey Bees (Apis mellifera), Knowledge Gaps and Future Perspectives

2021 ◽  
Vol 18 (4) ◽  
pp. 1863 ◽  
Author(s):  
Agata Di Noi ◽  
Silvia Casini ◽  
Tommaso Campani ◽  
Giampiero Cai ◽  
Ilaria Caliani
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Sublethal Effects ◽  
Integrated Approach ◽  
Anthropogenic Contamination ◽  
Knowledge Gaps ◽  
Pollination Services ◽  
General Decline ◽  
Polycyclic Aromatic ◽  
The Impact

Honey bees and the pollination services they provide are fundamental for agriculture and biodiversity. Agrochemical products and other classes of contaminants, such as trace elements and polycyclic aromatic hydrocarbons, contribute to the general decline of bees’ populations. For this reason, effects, and particularly sublethal effects of contaminants need to be investigated. We conducted a review of the existing literature regarding the type of effects evaluated in Apis mellifera, collecting information about regions, methodological approaches, the type of contaminants, and honey bees’ life stages. Europe and North America are the regions in which A. mellifera biological responses were mostly studied and the most investigated compounds are insecticides. A. mellifera was studied more in the laboratory than in field conditions. Through the observation of the different responses examined, we found that there were several knowledge gaps that should be addressed, particularly within enzymatic and molecular responses, such as those regarding the immune system and genotoxicity. The importance of developing an integrated approach that combines responses at different levels, from molecular to organism and population, needs to be highlighted in order to evaluate the impact of anthropogenic contamination on this pollinator species.

scholarly journals Grill Workers Exposure to Polycyclic Aromatic Hydrocarbons: Levels and Excretion Profiles of the Urinary Biomarkers

2020 ◽  
Vol 18 (1) ◽  
pp. 230
Author(s):  
Marta Oliveira ◽  
Sílvia Capelas ◽  
Cristina Delerue-Matos ◽  
Simone Morais
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Principal Component ◽  
Fold Increase ◽  
Urinary Biomarkers ◽  
Analysis Model ◽  
Exposed Workers ◽  
Polycyclic Aromatic ◽  
The Impact

Grilling activities release large amounts of hazardous pollutants, but information on restaurant grill workers’ exposure to polycyclic aromatic hydrocarbons (PAHs) is almost inexistent. This study assessed the impact of grilling emissions on total workers’ exposure to PAHs by evaluating the concentrations of six urinary biomarkers of exposure (OHPAHs): naphthalene, acenaphthene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene. Individual levels and excretion profiles of urinary OHPAHs were determined during working and nonworking periods. Urinary OHPAHs were quantified by high-performance liquid-chromatography with fluorescence detection. Levels of total OHPAHs (∑OHPAHs) were significantly increased (about nine times; p ≤ 0.001) during working comparatively with nonworking days. Urinary 1-hydroxynaphthalene + 1-hydroxyacenapthene and 2-hydroxyfluorene presented the highest increments (ca. 23- and 6-fold increase, respectively), followed by 1-hydroxyphenanthrene (ca. 2.3 times) and 1-hydroxypyrene (ca. 1.8 times). Additionally, 1-hydroxypyrene levels were higher than the benchmark, 0.5 µmol/mol creatinine, in 5% of exposed workers. Moreover, 3-hydroxybenzo(a)pyrene, biomarker of exposure to carcinogenic PAHs, was detected in 13% of exposed workers. Individual excretion profiles showed a cumulative increase in ∑OHPAHs during consecutive working days. A principal component analysis model partially discriminated workers’ exposure during working and nonworking periods showing the impact of grilling activities. Urinary OHPAHs were increased in grill workers during working days.

scholarly journals Evaluating the impact of exposure to environmental contaminants on human health

1996 ◽  
Vol 42 (8) ◽  
pp. 1345-1349 ◽  
Author(s):  
J B Silkworth ◽  
J F Brown
Keyword(s):  
Chemical Substances ◽  
The Public ◽  
Aromatic Hydrocarbon Receptor ◽  
Naturally Occurring ◽  
Synthetic Chemicals ◽  
Low Concentrations ◽  
Polycyclic Aromatic ◽  
Coplanar Polychlorinated Biphenyls ◽  
Proportional Contribution ◽  
The Impact

Abstract Humans are exposed daily to low concentrations of many different chemical substances, natural and some man-made. Although many of these substances can be toxic at high levels, typical exposures are far below the effect levels. The responses produced by man-made aromatic hydrocarbon receptor agonists, such as dioxins, polychlorinated dibenzofurans, coplanar polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, are also produced, often to greater extents [corrected], by naturally occurring constituents of fried meat, cabbage, broccoli, cauliflower, cocoa, and curry. Our society seems to be concerned about the health risks associated only with the synthetic chemicals, regardless of their proportional contribution to the total agonist activity, and regulates on the basis of such concerns. It would be more protective of the public health to determine acceptable concentrations for each type of response, regardless of the origin of the inducing agent, and issue advisories or regulations accordingly.

The impact of biochars on sorption and biodegradation of polycyclic aromatic hydrocarbons in soils—a review

2014 ◽  
Vol 22 (5) ◽  
pp. 3314-3341 ◽  
Author(s):  
Chinedum Anyika ◽  
Zaiton Abdul Majid ◽  
Zahara Ibrahim ◽  
Mohamad Pauzi Zakaria ◽  
Adibah Yahya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic ◽  
The Impact ◽  
Hydrocarbons In Soils

scholarly journals Thermal processing contaminants in foodstuffs and potential  strategies of control

2004 ◽  
Vol 22 (SI - Chem. Reactions in Foods V) ◽  
pp. S1-S10 ◽  
Author(s):  
A. Studer ◽  
I. Blank ◽  
R. H Stadler
Keyword(s):  
Health Risks ◽  
Food Service ◽  
Food Product ◽  
Heterocyclic Aromatic Amines ◽  
Heat Processing ◽  
Food Container ◽  
Mechanisms Of Formation ◽  
Polycyclic Aromatic ◽  
Us Fda ◽  
The Impact

Over the past decades, researchers from academia, industry, and National authorities and enforcement laboratories, have gained increasing insight in understanding the presence, formation and potential risk to public health posed by the compounds formed during the domestic cooking and heat-processing of different foods. Compounds already intensively studied are the heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, and chloropropanols. Concrete measures have been introduced by the food industry to control certain contaminants, exemplified by the introduction of enzymatic hydrolysis of plant proteins or over-neutralization to reduce concentrations of chloropropanols in savoury flavours. The recent discovery of acrylamide in cooked foods has raised much concern, and sparked intensive scientific studies into the occurrence, analysis, exposure, mechanisms of formation, possible measures of control, and toxicology of the compound. However, since acrylamide formation is directly linked to the desired Maillard reaction that generates important flavour and aroma compounds – as well as chemicals with potentially beneficial health effects – any measures taken must assess the impact on overall quality and consumer acceptance of the food product. In addition, mitigation must be devised in such a way as not to increase the risks for other possibly more severe short and medium to long-term health risks. In this context, understanding the impact of changes in processing on the safety of foods will be of paramount importance. In May 2004 the US FDA published findings of trace levels of furan in different foods, corroborating older data and raising some concerns, albeit without reference to any health risks. Particularly canned and jarred foods that are subject to thermal treatment are apparently affected, as the volatile furan is essentially “trapped” in the food container. Analogous to the acrylamide concern, there is a paucity of knowledge in all scientific domains, i.e. exposure, methods of analysis, mechanisms of formation, toxicology. Finally, a concern that needs to be addressed is the lack of knowledge about the effects of final preparation in food service and domestic situations on the formation of processing contaminants. In essence, consumers should follow sound dietary and health advice by choosing diets based on balance, variety and moderation.

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