Thermal Power Plant Fly Ash Research Articles

An investigation of green diesel produced through hydro-processing of waste cooking oil using an admixture of two heterogeneous catalysts

ABSTRACTEnergy crisis, global warming, and rapid depletion of fossil fuel reservoirs are knocking the door for alternative fuel. This study explores the hydro-processing of waste cooking oil using mixtures of two heterogeneous catalysts (admixture of calcium oxide and biomass-based thermal power plant fly ash (​BBTPFS)) in different proportions (10, 20, 30, and 40% of CaO in BBTPFS by wt%) to analyze the effect on the yield of bio-crude, organic liquid fraction (OLF), and acidity index. The high-pressure high-temperature reactor was used for hydro-processing, and True Boiling Point (TBP) distillation unit was used for fractional distillation of the bio-crude obtained within the boiling range, 35–140°C, 140–180°C, 180–370°C, and 370–482°C as per ASTM D2892 and ASTM D5236 specification. The yield of bio-crude and OLFs and their characterization have been analyzed and compared with literature work. It was observed that 20 wt% of CaO in BBTPFS catalyst was the optimized admixture to obtain the maximum yield of bio-crude (93.85 vol%) and OLFs (66.29 vol%) with lower acidity index.

Kömür Baca Külü, Kireç ve Jips Ürünlerinden Yapı Malzemesi Yapımı

Approximately 80 per cent and 20 per cent of the total solid waste resulting from the burning of lignite coal in thermal power plants are fly ash and bottom ash, respectively. This material is stored in natural terrain. In order to generate 1 kWh of power approximately 110 grams of ash is produced and a thermal power plant of 1000 MW capacity produces some 650 000 tons of ash on a yearly basis. About 20,000 MW of electricity is generated annually from thermal power plants operating in our country, resulting in 13 million tons of ash. Some 400 thousand tons of ash per year is being produced in Sivas-Kangal thermal power plant of 457 MW installed capacity. This material is not considered in any way. Sivas basin contains billions of tons of gypsum resources. In this study, production of lightweight building material was investigated experimentally by mixing different ratios of gypsum and lime with the Kangal thermal power plant fly ash. Required tests were carried out in accordance with relevant standards. It has been determined that D-17 labeled mass 70% plaster, 10% fly ash and 20% of the mixture have more optimal values ​​than the other mixtures. With the addition of different additives to the sample series labeled D-17, the pressure resistance increased from 92,8 kg / cm² to 113,8 kg / cm², while the water absorption ratios were reduced from 45,8% to 19,1% and to 6,9% with the addition of water repellent. It was found that there is an exponential relationship between Shore hardness value and bending strength (R 2 = 0,81) that all samples have a high correlation (R 2 = 0.95) linear relationship between density and bending strength.

Extraction of aluminium as aluminium sulphate from thermal power plant fly ashes

Abstract Valuable metal extraction technology from thermal power plant fly ash is limited. In the present study, aluminium is extracted from fly ash as highly pure aluminium sulphate (>99.0%) by leaching with sulphuric acid, followed by pre-concentration and successive crystallization. Two types of fly ashes from different sources, i.e., Talcher Thermal Power Station (TTPS) and Vedanta Aluminium Company Limited (VAL) were chosen for comparative study on the extraction of aluminium as aluminium sulphate. The product is characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Purity of aluminium sulphate was also investigated by inductively coupled plasma–optical emission spectrometry (ICP–OES). The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio (fly ash : 18 mol/L H 2 SO 4 , g/mL) and particle size of fly ashes. Physico-chemical analysis indicates that the obtained product is Al 2 (SO 4 ) 3 ·18H 2 O, having low iron content (0.08%).

Use of solid residue from thermal power plant (fly ash) for enhancing sewage sludge anaerobic digestion: Influence of fly ash particle size

The influence of fly ash particle size on methane production and anaerobic biodegradability was evaluated. Assays with different fly ash particle sizes (0.8–2.36mm) at a concentration of 50mg/L were ran under mesophilic conditions. In anaerobic processes operating with fly ash, greater removal of both volatile total and suspended solids, chemical oxygen demand (total and soluble) was achieved, with an increase of methane production between 28% and 96% compared to the control reactors. The highest increase occurred at ash particles sizes of 1.0–1.4mm. The metal concentrations in the digestates obtained after anaerobic digestion of sewage sludge are far below those considered as limiting for the use of sludge in soils.

Application of sol–gel technique for preparation of nanosilica from coal powered thermal power plant fly ash

Fly ash, a thermal power plant by-product is increasing and it is expected that this by-product will increase with increase in energy demand, especially in developing countries. Considering this, current study presents a novel process for the utilization of thermal power plant waste i.e., (fly ash) by fractionating it into silica particles and aluminum enriched residual ash. Fractionation of fly ash helped to extract industrial grade pure form of nanosilica. As a first step fly ash was added into 2N Sodium hydroxide solution, and resulting suspension was autoclaved for 120 min duration at 100 °C. After filtration, supernatant was collected and 1N HCl was added drop-wise, allowing precipitation of silica in the solution. A white cloudy gel-like precipitate of silica was formed which was filtered and washed several times to remove the impurities of Na, K, and chloride salts. This procedure yielded the nanosilica a final product, which was characterized for crystalline index and composition by using X-ray diffraction and fluorescence technique. The result of X-ray diffraction shows a broad hump in the region of 20°–22° indicating amorphous nature of the product was studied using field emission scanning electron microscopic and transmission electron microscopic analytical technique was used to study about internal structure, morphological features and size of the molecules which depicts spherical globular silica particles in 10–40 nm range. Further, chemical bonds were studied by infrared analysis (fourier transform infrared) and results indicated the presence of silica oxygen bonding (–Si–O–Si–) at 785 cm−1 and Si–OH bonds 3000–3500 cm−1. Energy dispersive X-ray analysis shows the presence of silicon and oxygen elements, which forms 99.9% of prepared nanosilica particles by weight.

RECOVERY OF TRACE ELEMENTS WITH URANIUM AND THORIUM FROM YATAGAN THERMAL POWER PLANT FLY ASHES BY LEACHING

In this paper, characterization of fly ashes obtained from the Yatagan Thermal Power plant, Mugla, Turkey was performed in order to determine their radioactive element contents, especially uranium and thorium. The representative fly ash samples were subjected to hydrochloric acid (HCl) leaching considering solid concentration, acid dosage, leaching time and temperature in order to reach certain uranium and thorium recoveries. The obtained results showed that the optimum conditions for leaching tests were: 30% solid concentration, 2.36 mmol/dm 3 HCl addition, 240 min leaching time and 40 o C temperature. Dissolution efficiencies for uranium and thorium from the Yatagan Thermal Power Plant fly ashes were calculated as 90.12 and 81.18%, respectively.

Fine-grained concrete with organomineral additive

The article deals with the issues concerning the formation of the structure and properties of fine-grained concrete with organomineral additive produced through mechanochemical activation of thermal power plant fly ash together with superplasticizer. The additive is produced in a high-speed activator at the collision particles’ speed of about 80 m/s. The use of the additive in fine-grained concrete in the amounts of 0.5-1% increased the strength by 30-50% and reduced the size and volume of pores. The cement consumption in such concrete is close to the cement consumption in common concrete of equal resistance.

Separation of ultrafine particles from class F fly ashes

In this study, ultrafine particles were recovered from Catalagzi (CFA) and Sugozu (SFA) thermal power plant fly ashes using a specific hydraulic classification technology. Since fly ashes have a high tendency to be flocculated in water, settling experiments were first designed to determine the more effective dispersant and the optimum dosage. Two different types of the superplasticizers (SP) polymers based on sulphonate (NSF, Disal) and carboxylate (Glenium 7500) were used as the dispersing agents in these settling experiments. Hydraulic classification experiments were then conducted to separate ultrafine fractions from the fly ash samples on the basis of the settling experiments. According to the settling experiments, better results were achieved with the use of Disal for both CFA and SFA. The classification experiments showed that the overflow products with average particle sizes of 5.2 μm for CFA and 4.4 μm for SFA were separated from the respective as-received samples with acceptable yields and high enough recoveries of -5 μm (ultrafine) particles. Overall results pointed out that the hydraulic classification technology used provided promising results in the ultrafine particle separations from the fly ash samples.

The impact of re-entrainment on the electrocyclone effectiveness

Abstract The problem of fine particle gas cleaning is especially actual at the present time. This is due to the need to capture the desired product and waste gases cleaning. In both cases, the equipment should provide maximum collection efficiency. Cleaning of gas from thermal power plant (TPP) fly ash is serious problem. Coal-fired thermal power plants provide 27% of the total world energy consumption. Conventional TPP produce more than 700,000 tonnes of fly ash per year. Annually fly ash production only in Russia, according to various estimates, is 27–35 million tons. Various apparatus are used to clean the gases from the fly ash. Required collection efficiency of purification units must to be 99.5–99.7% and higher. Wet scrubbers makes ash recycling more difficult. It requires ash separation from the slurry and drying. One solution of gas cleaning problem is a electrocyclone. It provides gas purification efficiency up to 99.9% at initial ash concentration equal 50 g/m 3 and higher. An electrocyclone allows to obtain a product in dry form. Re-entrainment is return of captured material to clean gas stream. Re-entrainment in the gas cleaning equipment is one of the negative effects. Re-entrainment reduces equipment efficiency at high gas velocities. The present study was carried out to determine the value of re-entrainment in the electrocyclone. The object of study was the electrocyclone of ‘pipe in pipe’ type. Aluminosilicate fly ash from thermal power plant (TPP) was the test material. Study was carried out in dry and wet modes. Re-entrainment was observed in dry operation mode. No re-entrainment was observed in wet operation mode. The value of re-entrainment was calculated. It decreases collection efficiency from 99.9% to 60%. Re-entrainment depends on aerosol velocity (range 14–27 m/s) and the aerosol concentration (range 2–30 g/m 3 ). It is shown, what re-entrainment can be eliminated by water irrigation of collecting electrodes.

An investigation of catalytic hydrocracking of high FFA vegetable oils to liquid hydrocarbons using biomass derived heterogeneous catalysts

Catalytic hydrocracking of high free fatty acid (FFA) containing Mesua ferrea L. and Jatropha curcas oil (triacylglycerol) was investigated using biomass derived heterogeneous catalysts viz. Musa balbisiana Colla underground stem (MBCUS) nanomaterial and biomass based thermal power plant fly ash (BBTPFS). Reactions were studied in a batch mode in a bench scale reactor at 400°C under variable initial H2 pressure (1–75bar) for 1–4h using 1–5wt.% catalysts loading. Our results confirm that the reaction network consisted of multiple pathways leading to a product mixture rich in hydrocarbons, non-polar oxygenates and organic acids commonly known as biocrude. Decarboxylation, hydrolysis, hydrocracking and thermocatalytic cracking appeared to be the dominating reactions subsequently leading to the production of hydrocarbon mixture of chain length C8–C19. The resultant biocrude was fractionated into four fractions within the boiling range 35–140°C, 140–180°C, 180–370°C and 370–482°C as per ASTM D2892 and ASTM D5236 specifications. Further, the recovery in each fraction was directly affected by biocrude quality which in-turn was dependent upon catalyst properties and reaction conditions. The reaction networks were also varied significantly with respect to reaction atmosphere and as well as for the two catalysts which directly affected the yield and quality of product (higher heating value, acidity index, liquid distillate recovery etc). To summarize, BBTPFS was found to be a more effective catalyst for acidity and heteroatom removal, and consequently, produced biocrude with lowest acidity and highest percentage (≥65%) of the product in the liquid hydrocarbon range.

Use of fly ash in production of light-weight building bricks

Fly ash is one of the coal combustion products (CCPs) of coal burning power plants and it contains substantial amounts of potentially harmful constituents to the environment. It is known that nearly 600 million tons of fly ash is produced in the world per-annum. In Turkey, the annual production of fly ash is, on average, 13 million tons and only a small amount of this is utilized. This study examines the production of light-weight, high thermal insulating bricks made out of the fly ash and lime. Cylindrical brick samples were produced through steam curing of Seyitömer thermal power plant fly ash and lime mixtures in an autoclave in order to determine the optimum conditions for mechanically sound bricks. Subsequently, at the optimum conditions determined, real-size bricks were produced and subjected to standard tests. The findings of this paper suggest that fly ash/lime bricks can be an alternative product to aerated cellular concrete.

Investigation of adsorption of Basic Blue 41, Acid Violet 17 and Reactive Red 23 dyestuffs on Çatalağzı Thermal Power Plant flyash

In this study the various dyestuffs in industrial wastewaters (Basic Blue 41, Acid Violet 17, Reactive Red 23) was investigated adsorption on fly ash whiche is a waste. Dyestuff adsorption on fly ash carried out in batch system has been investigated as a function of medium pH, temperature and the amount of adsorbent. In the other part of the study, fly ash samples treated using H 2 SO 4 and heat have been studied for dye adsorption. After acid and heat treatment, the specific surface area of the fly ash and the dye adsorption capacity increased. The results of adsorption equilibrium obtained by untreated of fly ash were examined for compliance of Langmuir and Freundlich isotherm models. Dye adsorption systems data were fitted better to the Langmuir izoterm. The Gibbs free energy of adsorption (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) were calculated using the adsorption isotherms obtained at different temperatures. Negative Gibbs free energy shows the dye adsorption onto flyash is spontaneous.

Characterization, activity and process optimization with a biomass-based thermal power plant's fly ash as a potential catalyst for biodiesel production

A typical thermal power plant operated using 70–80% gram straw, 10–15% cotton straw, 5–10% wheat straw and leaves (2%) with a small quantity of coal (1–2%) as fuel mixture, produces a residue called Biomass-Based Thermal Power Plant Fly Ash (BBTPFS)

Analysis of metal Bioleaching from thermal power plant fly ash by Aspergillus niger 34770 culture supernatant and reduction of phytotoxicity during the process.

Aspergillus niger culture supernatant is used for bioleaching process. Before starting bioleaching process, fly ash was washed with distilled water. This removed 100 % sodium, 47 % (±0.45) boron, 38.07 % (±0.12) calcium, 29.89 % (±0.78) magnesium, and 11.8 % (±0.05) potassium. The pH was reduced from 10.5 to 8.5 after water washing. During bioleaching process, around 100 % metal removal was achieved in 4 h for all metals except chromium 93 % (±1.18), nickel 83 % (±0.32), arsenic 78 % (±0.52), and lead 70 % (±0.20). The process parameters including temperature, shaking speed, and solid/liquid ratio were optimized for bioleaching process. Experiments were conducted to evaluate effect of fly ash on growth of mung bean (Vigna radiata). At 20 g/100 ml fly ash concentration no germination of V. radiata seeds was observed. With an increasing concentration of untreated fly ash, a gradual decrease in root/shoot length was observed. After bioleaching process 78 % (±0.19) germination of V. radiata was observed with 20 g/100 ml fly ash. This study will help to develop an efficient process to remove the toxic metals from fly ash.

Recovery of the Rare Metals from Various Waste Ashes with the Aid of Temperature and Ultrasound Irradiation Using Chelants

The incineration fly ash (IFA), molten fly ash (MFA), thermal power plant fly ash (TPP-FA), and nonferrous metal processing plant ash (MMA) have been screened in terms of the following rare-termed metal contents: B, Ce, Co, Dy, Eu, Ga, Gd, Hf, In, Li, Lu, Mn, Nb, Nd, Ni, Pr, Rb, Sb, Se, Sm, Sr, Ta, Tb, Te, Ti, Tm, V, W, Y, and Yb. The pseudo-potential for recycling of the waste ashes, as compared to the cumulative concentration in the crust (mg kg−1), was determined as follows: MMA > IFA > MFA > TPP-FA. The comparison with the crude ore contents indicates that the MMA is the best resource for reprocessing. The recovery of the target metals using aminopolycarboxylate chelants (APCs) has been attempted at varying experimental conditions and ultrasound-induced environment. A better APC-induced extraction yield can be achieved at 0.10 mol L−1 concentration of chelant, or if the system temperature was maintained between 60 to 80 °C. Nevertheless, the mechanochemical reaction induced by the ultrasound irradiation has been, so far, the better option for rare metal dissolution with chelants as it can be conducted at a minimum chelant concentration (0.01 mol L−1) and at room temperature (25 ± 0.5 °C).

Single and binary adsorption of heavy metals on fly ash samples from aqueous solution

Thousands of toxins are released every day into the environment through numerous industrial operations and this resulted in continuous search for newer adsorbents. Two types of adsorbents, 1:10 fly ash and 1:15 fly ash samples were prepared from coal fired thermal power plant fly ash by treating it with calculated amount of calcium carbonate and phosphoric acid. Adsorbents were characterized on the basis of FTIR, XRF, surface area, pH and particle size studies. Adsorption of Pb(II), Ni(II) and Cr(VI) from single metal solutions on 1:10 fly ash from aqueous solution was carried out as a function of initial metal ion concentration, adsorbent dose, contact time and pH of the solution. Adsorption data obtained was analyzed with Langmuir, Freundlich and Temkin adsorption isotherm equations. Binary adsorption of Pb(II) and Ni(II) was studied on 1:10 and 1:15 fly ash samples as a function of initial metal ion concentration to investigate their efficiencies in removing metal ions from aqueous solution. In the case of 1:10 and 1:15 fly ash samples, Pb(II) and Ni(II) removal was observed to be almost the same. The significant difference observed between single and binary metal adsorption is in the initial metal removal rate. Slightly lower initial metal removal rate observed in the case of binary adsorption is probably due to the presence of competing metal ions in the solution. Fly ash based adsorbents prepared in the laboratory exhibited comparatively more adsorption capacity than that of the parent material, fly ash. Further, used adsorbents can be disposed in the form of concrete blocks as leaching of toxic metals is almost nil both under mild acidic and basic conditions. As cost involved in developing adsorbents from fly ash is comparatively less than other commercial adsorbents, reactivation or regeneration of used adsorbents was not considered.

Characterization of sintered class F fly ashes

In this study sinterability of the two class F fly ashes were investigated as a function of sintering temperature and sintering time. For this aim, Çatalağzı and Sugözü thermal power plant fly ashes resulted from burning of bituminous coals were first pressed into cylindrical specimen, and then sintered to form ceramic materials without the addition of any materials like organic binders or inorganic additives. Sintering efficiency was evaluated in terms of ceramic specifications such as density, water absorption, shrinkage and splitting tensile strength. Furthermore, phase developments and microstructural changes due to sintering process were determined with X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Overall results have shown that Sugözü fly ash seems to have better sintering properties than Çatalağzı fly ash due to the better microcrystalline structure, higher density and strength with the lower porosity, water absorption and shrinkage values.

Experimental Study on Synthesis of Adsorption Material of Porous Zeolite with Fly Ash

This paper investigates the use of a thermal power plant fly ash as raw materials for preparing zeolite test method. Process is making fly ash and sodium hydroxide in certain proportion mixed,calcined, grinded, stired, aged, washed, dryed. Finaly it develops with ideal adsorption properties of porous zeolite materials. The material in industrial water treatment and air purification field has broad application prospects.

Thermal Co-processing of High Density Polyethylene with Coal, Fly Ashes, and Biomass: Characterization of Liquid Products

Co-pyrolysis of high density polyethylene with low cost additives, such as bituminous coal, bagasse fly ash, coal-based thermal power plant fly ash, and deoiled cake of jatropha, has been carried out in a batch reactor in the presence of nitrogen at 450°C under atmospheric pressure. Liquid products obtained by co-pyrolysis were characterized by ASTM D86 and gas chromatography/mass spectrometry. The yield of liquid product was found to be 54% upon pyrolysis of only high density polyethylene. It increased to between 63 and 80% when high density polyethylene was co-processed with bagasse fly ash, coal-based thermal power plant fly ash, bituminous coal, and deoiled cake of jatropha. ASTM D86 (boiling point distribution) analyses of liquid product from only high density polyethylene pyrolysis indicated that 62% diesel-like, 35% gasoline-like, and 3% heavier had formed. Co-processing high density polyethylene with bagasse fly ash, coal-based thermal power plant fly ash, bituminous coal, and deoiled cake of jatropha considerably (by 16 to 30%) improved the gasoline-like fraction's yield. This improvement was observed in the order of bagasse fly ash > coal-based thermal power plant fly ash > bituminous coal > deoiled cake of jatropha > high density polyethylene, while the yield of the diesel-like fraction followed the reverse order. Gas chromatography/mass spectrometry analyses demonstrated that the co-processing afforded 45–55% increase in C6-C12 fractions over that from high density polyethylene only. This increase paralleled the trend observed for gasoline-like fractions. Co-processing led to the addition of aromatics (2%) and oxygenates (6–15%) at the cost of paraffins (reduction by about 10–20%) in the liquid products. In general, results indicated that there exists a synergy of reactive species when high density polyethylene was co-processed with bagasse fly ash, coal-based thermal power plant fly ash, bituminous coal, and deoiled cake of jatropha.

Kinetics and Adsorption Isotherm Study of Removal of Zn+2 ions from Aqueous Solution Using Thermal Power Plant Fly Ash

Kinetics and Adsorption Isotherm Study of Removal of Zn+2 ions from Aqueous Solution Using Thermal Power Plant Fly Ash