Concentrations of elements in Lias coals from the eastern Black Sea Region,NE-Turkey

The element contents and organic matter-element relation between Lias-aged coals exposed in four fields in Gümü?hane and Bayburt were investigated. In general, fixed carbon and gross calorific values of the Edire and Balkaynak coals are higher than Güvercinlik and Çerçi coals. The highest ash yields were observed in the Çerçi coals. The concentrations of Mg, P, Ca, Mo, Y, Ni, U, Zn, Ga, Ba, W, Sr, Ta, and Be of the analysed coals are positively correlated with ash yield, indicating an organic affinity. The Lias-aged coals located in Gümü?hane and Bayburt are low-rank coals.     

Emission of trace elements from coal-fired industrial boilers. A survey of relevant literature

Present evidence is not sufficient for an evaluation of the hazard, if any, that might be caused by trace elements as a result of the increasing industrial market for coal. Measurements are reported for large pulverized fuel plant and small experimental, fluidized bed combustion rigs but there are hardly any data relating to industrial boilers. Present data are too inconsistent to permit generalized conclusions. Methods of sampling, sample preparation and analysis are assessed and those most suitable for a comparison of emissions from fluidized bed and stoker fired boilers are indicated.     

Pre-combustion removal possibility of hazardous trace elements from Indian high-ash coal by coal preparation technologies

Many of the potentially hazardous air pollutants listed in the 1990 Clean Air Act are elements commonly found in trace amounts in coal. When coal is burned, these elements release into the environment. An option for controlling the release of these elements into the atmosphere is to remove them before combustion. Conventional physical coal cleaning processes are effective in reducing the concentration of many of these trace elements in coal. In addition, advanced cleaning processes directed toward reduction of various elements may perform better than conventional processes. Therefore, current research focuses on the advanced coal cleaning technology which is directed toward reduction of mineral matter and various toxics elements as well. Results of recent studies indicate that the degree to which a specific trace element can be reduced by coal cleaning depends on its distribution in the coal. To quantify the capabilities of a gravity-based coal cleaning process for removing these hazardous air pollutants, a detail study was conducted on a coal sample collected from one mine of Talcher area. Careful analysis of the experimental data indicates that most of the trace elements of greatest environmental concern are strongly associated with the organic matter of the investigated coal, thus during beneficiation these elements are concentrated in the clean coal fraction. Therefore, it makes the situation more complex and the expected pre-combustion removal of these trace elements seems to be not possible for the high-ash non-coking coals of Talcher coal field.     

Partitioning of rare earths and some major elements in the Kizildere geothermal field, Turkey

Rare earth elements and yttrium (REY), Na⁺, K⁺, Cl⁻, and Ca²⁺ were determined in water, steam, mineral scale and rock samples from the Kizildere geothermal field, Turkey. The CO₂-rich parent fluid originates from a sequence of mica schists with marble intercalations. The chemistry of the parent fluid varies with location and time. The average REY composition of the fluids is derived by extrapolation to the lowest Ca concentrations. The apparent vapor–liquid partitioning factors for REY at 145 °C and 5 bar total absolute pressure are about 0.2, whereas for Ca²⁺, Na⁺, K⁺ and Cl⁻ they are <0.05, about 0.0005, 0.0005 and about 0.02, respectively. Apparent scale-liquid distribution coefficients for REY at 145 and 190 °C are about 0.15 and 0.55, whereas at 100 °C they increase from 0.3 (La) to 1.5 (Lu).     

Petrography of Feed Coals in the Soma Power Plant,Manisa, Turkey

The coal-bearing Soma basin is one of the most productive lacustrine coal basins of western Anatolia-Turkey. This study mainly focuses on petrography of the feed coals (FCs) in the Soma power plant. A total of 16 feed coal samples were systematically collected once a week over an eight-week period from both group boiler units, B1–4 with 660 MW and B5–6 with 330 MW capacity. The most abundant maceral group of FCs is huminite, in which texto-ulminite, eu-ulminite, attrinite, densinite are rich. Liptinite group macerals in FCs include mainly sporinite, resinite, and liptodetrinite, which are considerably higher than the other identified liptinite macerals. In the inertinite group, fusinite and inertodetrinite are more abundant. Identifiable minerals with petrographical studies are pyrite, siderite, other minerals (e.g., carbonates, clay minerals, quartz, feldspar, etc.), and fossil shells. This study shows that FCs used are subbituminous in rank with mean random ulminite reflectance of 0.43%Rr oil from B1–4 units and 0.39%Rr oil from B5–6 units. This indicates that coal rank is slightly higher in the central mines (southern Soma) than in the Denis mines (northern Soma).     

Effects on enrichment characteristics of trace elements in fly ash by adding halide salts into the coal during CFB combustion

The effects on enrichment characteristics of trace elements (TEs) in fly ash by adding halide salts into the coal during coal combustion were conducted on a 6 kW_th circulating fluidized bed (CFB) experimental device. Results show that unburn carbon content in fly ash has little relationship with the concentration of TEs namely Hg, As, Pb, Cr and Mn. All the TEs are enriched in fly ash for the raw coal CFB combustion. Concentration of Hg and Mn increases with increasing the addition amount of CaCl₂, NH₄Cl and NH₄Br. As, Pb and Cr enrich in fly ash more strongly when adding more CaCl₂ into the coal while more addition of NH₄Cl and NH₄Br leads to the decrease of their enrichment compared to addition amount of 0.1 wt%. On the whole, putting halide salts into the coal results in the TEs enriched in fly ash, which benefits for TEs removal during the coal combustion. Combining this method with the chemical sequential extraction or thermal treatment of the fly ash will be a promising way to realize the TEs removal and their recovery.     

The geochemistry of trace elements in marine oil shales and their combustion residues: Occurrence and environmental aspects

With the aim of better understanding geochemistry of trace elements in marine oil shale and its combustion residues, 23 raw samples, 17 oil shale combustion residues, and 18 selected minerals from Bilong Co oil shale are studied. Potentially hazardous trace elements in raw samples include As, B, Cd, Mo, and Se, while Se, Mo, Cd, As, Bi, and U are potentially hazardous trace elements in combustion residues. As is controlled mainly by Fe-bearing minerals. B occurs mainly in clay minerals. Cd is enriched mainly in calcite. Mo is controlled mainly by organic matter. Se is mainly controlled by P-bearing minerals.     

Determining the effect of trace elements on biohydrogen production from fruit and vegetable wastes

Trace elements are one of the important parameters for dark fermentative H₂ production because they work as co-factors in H₂ formation biochemistry. Lack or excess of trace element and its concentrations could be an important reason for the low yield of H₂ production. In this study, the effects of 11 different trace elements (Fe, Ni, Zn, Co, Cu, Mn, Al, B, Se, Mo and W) were tested at two levels in terms of biohydrogen production from Fruit and Vegetable Wastes (FVW) with Biochemical Hydrogen Potential (BHP) Tests using Plackett-Burman statistical design. 1.1–2.8 times enhancement of biohydrogen production was determined with its addition. The most effective trace elements were found as Zn and Ni. In order to reveal the resident microbial flora, Denaturing Gradient Gel Electrophoresis (DGGE) analysis was carried out on all BHP effluent samples. Results of DGGE analysis, four microbial sequences evaluated as Clostridium sp., Clostridium baratii, Uncultured bacterium, Uncultured Streptococcus sp., and their similarity rates were 99%, 100%, 89%, 98%, respectively.     

Characterization of heavy metal trace elements in the fly ash from a thermal power plant

The disposal of fly ash in the thermal power plant is a challenging task. With the increase in the demand of the coal as fuel in thermal power plants, combustion products, such as coal ash, become a serious environmental problem due to their leaching characteristics. The objective of the present study was to investigate the leaching characteristics of the fly ash disposed in ash pond of thermal power plants. A series of leaching tests have been performed with different liquid-to-solid (L/S) ratio. The L/S ratio varies from 20:1 to 60:1. It is observed that the elements, such as Mn, Mg, Cr, Zn, Ni, Pb, Fe, and Cu, are most abundant elements, while Mo and Co are the least abundant elements. It is also observed that the leaching characteristics of the fly ash are affected by the pH of extraction solution and liquid-to-solid (L/S) ratio.     

Equilibrium calculations of As,Pb, and Hg speciations during coal combustion in atmospheres 21O2/79N2 and 30O2/70CO2

The research of this paper investigated the influence of a coal combustion atmosphere, pressure, and temperature on the equilibrium speciation of As, Pb, and Hg. The input data for calculations in the FactSage were the results of coal from the mine “Bogdanka”. A change in the combustion atmosphere from air to 30%O₂/70%CO₂ results in an increase in the mole fractions of As, Pb, and Hg species that occur in the gaseous phase, i.e. AsO, AsO₂, PbO, PbCl₂, HgCl₂, and Hg. At temperatures below 900°C, almost all arsenic moves to solid species in the form of salts derived from arsenic acid (V).     

Investigation of wind characteristics and wind energy potential in Kirklareli, Turkey

Utilization of wind energy as an energy source has been growing rapidly in the whole world due to environmental pollution, consumption of the limited fossil fuels and global warming. Although Turkey has fairly high wind energy potential, exploitation of the wind energy is still in the crawling level. In the current study, wind characteristics and wind energy potential of Kırklareli province in the Marmara Region, Turkey were analyzed taking into account the wind data measured as hourly time series. The wind data used in the study were taken from Electrical Power Resources Survey and Development Administration (EIEI) for the year 2004. The measured wind data were processed as annual, seasonal and monthly. Weibull and Rayleigh probability density functions of the location are calculated in the light of observed data and Weibull shape parameter k and scale parameter c are found as 1.75 and 5.25 m/s for the year 2004. According to the power calculations done for the site, annual mean power density based on Weibull function is 138.85 W/m². The results indicate that investigated site has fairly wind energy potential for the utilization.     

Source Rock Characterization and Depositional Environment of the Late Cretaceous Haymana Formation in the Salt Lake Basin of Turkey

Abstract

Late Campanian-Maestrichtian Haymana Formation of the Salt Lake Basin, Turkey was deposited in a forearch Basin. This formation has been studied by a combination of organic geochemical methods (LECO/Rock-Eval, sulphur, gas chromatography), light microscopy, and bulk combination method (elemental analysis) in order to assess the hydrocarbon source potential of the abundant and extensive shale intervals presents in the formation.

The shales have an organic carbon content (TOC) up to 1.69% and hydrogen index (HI) values up to 380. Pyrolysis yields (TOC, S ₂, and HI) and organic petrography (kerogen type, amount%) indicate that the shales are dominantly gas potential, containing Type III and II organic matter. Thermal maturity, assessed from Spore Colour Index and T _max, indicates that late Campanian-Maestrichtian Haymana Formation in the Salt Lake Basin range from diagenetic to over mature with respect to oil generation and may produce gas and oil.

The values for the V/Cr ratio of shales vary from 0.29 to 3.20, indicating dysoxic and anoxic conditions for bottom water.     

The effects of solid absorbents on the emission of trace elements,SO2, and NOx during coal combustion

The emission of toxic metals from the combustion of fossil fuels is an important global environmental issue. Solid absorbents can be used to control the emission of toxic trace elements from coal combustion. In this paper, limestone, CaSO₄, bauxite, kaolinite and CaO are employed for this purpose and experiments are carried out in an electrically heated drop‐tube furnace. The trace elements investigated are Pb, Cd, Cr and As. It is observed that the absorptive capacity is related to the qualities of the absorbents (type, amount and particle size) and the combustion temperature. The results also show that some absorbents can reduce SO₂ emission simultaneously, but no influence on NO_x emission. Copyright © 2001 John Wiley & Sons, Ltd.     

Estimation of solar radiation parameters for Izmir,Turkey

In this study, the solar radiation parameters (global and diffuse solar radiation) are correlated with respect to ambient temperatures in the fifth‐order polynomial form for Izmir in Turkey. Experimental data were measured in the Solar‐Meteorological Station of Solar Energy Institute in Ege University over a 5‐yr period, 1994–1998. The ratios of the total daily diffuse to global radiation intensities for each month range from 0.38 to 0.45 averaged for the same period, with an average value of 0.41. It can be concluded that the present models predict the solar radiation parameters reasonably well with the correlation coefficients over 0.95 for the projections. Copyright © 2002 John Wiley & Sons, Ltd.     

Generation of typical solar radiation data for İstanbul,Turkey

Typical solar radiation data are very important as input in modelling, designing and performance evaluation of solar energy applications. In this study, typical solar radiation data were obtained for ?stanbul, Turkey both from measured data and synthetic generation. Firstly, a test reference year for daily global solar radiation on a horizontal surface was generated using 19 years measured data. The daily global solar radiation as typical data for ?stanbul was presented throughout a year in a tabular form. Secondly, the daily global solar radiation for ?stanbul was expressed with a trigonometric equation using long‐term measured data. It is expected that the typical data and the equation derived will be useful to the designers of solar energy systems as well as those who need to have fairly good estimates of daily global solar radiation for ?stanbul. Copyright © 2003 John Wiley & Sons, Ltd.     

Comparison of solar radiation correlations for İzmir,Turkey

In this study, empirical correlations are developed to estimate the monthly average daily global solar radiation on a horizontal surface (H) for the city of ?zmir in Turkey. Experimental data were measured in the Solar–Meteorological Station of the Solar Energy Institute at Ege University. The present models are then compared with the 25 models available in the literature for calculating H based on the main percentage error, root mean error, the main bias error, and correlation coefficient. It can be concluded that the present models predict the values of H for ?zmir better than other available models. Copyright © 2002 John Wiley & Sons, Ltd.     

Hydrogeological and isotopic survey of geothermal fields in the Buyuk Menderes graben, Turkey

The main high and low enthalpy geothermal fields in the Buyuk Menderes graben (Western Anatolia) and their reservoir temperatures are as follows: Kizildere (242 °C), Germencik (232 °C), Aydin-Ilicabasi (101 °C), Yılmazkoy (142 °C), Salavatli (171 °C), Soke (26 °C), Denizli -Pamukkale (36 °C), Karahayit (59 °C), Golemezli (101 °C) and Yenice (70 °C). The geothermal systems are controlled by active graben faults. The reservoir rocks in the geothermal fields are the limestone and conglomerate units within Neogene sediments and the marble-quartzite units within Paleozoic metamorphic formations. There are clear δ¹⁸O shifts from the Mediterranean Meteoric Water Line (MMWL) in the Kizildere, Germencik and Aydin fields, where a good relation between high temperatures and δ¹⁸O shift has also been observed, indicating deep circulation and water rock interactions. In the Pamukkale, Karahayit, Golemezli and Yenice fields and in Soke region, low temperatures, small isotope shifts, shallow circulations and mixing with shallow cold water have been noted.     

Major and rare earth element contents in sedimentary rocks of the Haymana formation,Ankara, Turkey

The study area is located 4 km east of Haymana, Ankara, Turkey. Major and rare earth element (REE) contents in samples collected from siltstone, carbonaceous claystone, and marl of the Haymana formation in the studied region and their distribution with respect to lithology and correlation relations yield important data on the evaluation of forming conditions of basin. Regarding the abundance of elements in various lithologies, the first and second group elements (SiO₂, Al₂O₃, Na₂O, TiO₂, P₂O₅ and Fe₂O₃, K₂O, REE) are more abundant in carbonaceous claystone and siltstone than that in marl, indicating that they are of detrital origin and controlled by clays. The abundance of CaO and TOT/C is lesser in siltstone than that in carbonaceous claystone and marl, implying that they are in marine origin. This is also supported by the correlation of elements. Based on REE abundances, lithologies are ranked in the order of claystone > siltstone > marl, which indicates that clays play an important role in REE enrichment. Correlation of REEs with major elements is indicative of detrital source and association with clay minerals. All the samples are represented by slightly negative Ce anomaly and positive Eu anomaly. Negative Ce and positive Eu anomalies are mostly typically of high oxygenated environments. Since negative Ce anomaly restricts oxygen enrichment to some extent, deposition environment might reflect oxic-anoxic conditions.     

Assessment of small hydropower (SHP) development in Turkey: Laws,regulations and EU policy perspective

This paper aims to evaluate the development of small hydropower (SHP) in Turkey and discusses the current situation of SHP plants in terms of government policy, economical aspects and environmental impacts taking EU policy into account. The laws published in recent years in Turkey succeeded in promoting the utilization of renewable energy for electricity generation, but it is considered that those laws are not fully compatible with EU policy. After the publication of Renewable Energy Law (Law No. 5346) there occurred a boost in SHP project along with hydropower development. Thus, the hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. Investment and operating costs are in favor of SHP development in Turkey as having the lowest costs among European countries (300–1000 €/kW as investment cost and 1 €cent/kWh as operating cost). Turkish governments have taken precautions for environmental issues resulted from renewable energy utilization but these are obviously not adequate. It is concluded that more attention must be paid on environmental issues and monitoring of the facilities must be enabled with further laws or regulations.     

生物质与三种不同变质程度的煤混合热解H2S析出规律

采用热重分析和色谱、质谱偶联技术,对玉米秆与三种不同变质程度的煤混合热解中产生的H2S气体进行了在线检测,研究生物质对不同煤种热解析出H2S气体的影响.研究表明:生物质与不同变质程度的煤的混合热解过程中H2S析出有着相似的规律,即生物质的加入使煤析出H2S提前,且随着生物质比例的增加,H2S在更低的温度下有较大的析出速度.生物质与煤共热解时,在380℃以前析出的H2S的浓度和析出量都比煤单独热解时的高,且随着生物质加入比例的增加而增加,这是生物质加氢作用的影响.且随着煤中含氢量的增加,生物质对煤热解过程的加氢作用表现得越不明显.生物质与不同变质程度的煤的混合热解过程中H2S析出规律是生物质加氢作用和矿物质固硫作用的综合结果.