The Experts below are selected from a list of 77373 Experts worldwide ranked by ideXlab platform
P A Strizhak - One of the best experts on this subject based on the ideXlab platform.
-
environmental economic and energetic benefits of using coal and oil Processing Waste instead of coal to produce the same amount of energy
Energy Conversion and Management, 2018Co-Authors: G S Nyashina, Margarita A Kurgankina, P A StrizhakAbstract:Abstract The replacement of coals by less environmentally hazardous coal-water slurries with and without petrochemicals is often discussed with an emphasis on quite a long list of advantages of composite fuels. In this research, we perform a compound analysis of the main prospects of switching from coal to slurries containing coal and oil Processing Waste. The main focus is on comparing a group of parameters to produce the same amount of heat from the combustion of coals and high-potential fuels. The compound analysis includes fuel consumption, the most hazardous anthropogenic emissions (sulfur and nitrogen oxides), the mass of the ash residue, the cost of components as well as their properties and concentrations. The numerical values of the relative efficiency factor of fuels based on municipal and industrial Wastes vary in a wide range from 2 to 165. The best results are shown by the slurries based on flotation Wastes (filter cakes) of coking and nonbaking coals (ranks C and N). For them, the aggregated criterion indicators are 70–90% higher than for the respective coals. A forecast has been made on the amount of energy that can be generated using fuels from Wastes. According to our forecast, the Waste-based fuels under study may be used to generate 773 TWh of energy annually.
-
experimental evaluation of main emissions during coal Processing Waste combustion
Environmental Pollution, 2018Co-Authors: Margarita A Dmitrienko, Jean Claude Legros, P A StrizhakAbstract:Abstract The total volume of the coal Processing Wastes (filter cakes) produced by Russia, China, and India is as high as dozens of millions of tons per year. The concentrations of CO and CO2 in the emissions from the combustion of filter cakes have been measured directly for the first time. They are the biggest volume of coal Processing Wastes. There have been many discussions about using these Wastes as primary or secondary components of coal-water slurries (CWS) and coal-water slurries containing petrochemicals (CWSP). Boilers have already been operationally tested in Russia for the combustion of CWSP based on filter cakes. In this work, the concentrations of hazardous emissions have been measured at temperatures ranging from 500 to 1000°С. The produced CO and CO2 concentrations are shown to be practically constant at high temperatures (over 900°С) for all the coal Processing Wastes under study. Experiments have shown the feasibility to lowering the combustion temperatures of coal Processing Wastes down to 750–850°С. This provides sustainable combustion and reduces the CO and CO2 emissions 1.2–1.7 times. These relatively low temperatures ensure satisfactory environmental and energy performance of combustion. Using CWS and CWSP instead of conventional solid fuels significantly reduces NOx and SOx emissions but leaves CO and CO2 emissions practically at the same level as coal powder combustion. Therefore, the environmentally friendly future (in terms of all the main atmospheric emissions: CO, CO2, NOx, and SOx) of both CWS and CWSP technologies relies on low-temperature combustion.
-
environmentally and economically efficient utilization of coal Processing Waste
Science of The Total Environment, 2017Co-Authors: Margarita A Dmitrienko, P A StrizhakAbstract:Abstract High concentrations of hazardous anthropogenic emissions (sulfur, nitrogen and carbon oxides) from solid fuel combustion in coal burning plants cause environmental problems that have been especially pressing over the last 20–30 years. A promising solution to these problems is a switch from conventional pulverized coal combustion to coal-water slurry fuel. In this paper, we pay special attention to the environmental indicators characterizing the combustion of different coal ranks (gas, flame, coking, low-caking, and nonbaking coals) and coal-water slurry fuels based on the coal Processing Waste – filter cakes. There have been no consistent data so far on the acceptable intervals for the anthropogenic emissions of sulfur (SO x ), nitrogen (NO x ) and carbon (CO, CO 2 ) oxides. Using a specialized combustion chamber and gas analyzing system, we have measured the concentrations of typical coal and filter-cake-based CWS combustion products. We have also calculated the typical combustion heat of the fuels under study and measured the ratio between environmental and energy attributes. The research findings show that the use of filter cakes in the form of CWS is even better than coals in terms of environment and economy. Wide utilization of filter cakes solves many environmental problems: the areas of contaminated sites shrink, anthropogenic emissions decrease, and there is no need to develop new coal mines anymore.
-
ignition of promising coal water slurry containing petrochemicals analysis of key aspects
Fuel Processing Technology, 2016Co-Authors: Dmitrii O Glushkov, S V Syrodoy, Arkadiy V Zhakharevich, P A StrizhakAbstract:Abstract An experimental study of the macroscopic laws of the ignition of coal-water slurry containing petrochemicals (CWSPs) based on coal and flammable liquids Processing Waste is presented. Investigations have been performed to determine the prospects for burning such fuel mixtures prepared from raw materials in power plants at temperatures ranging from minimal (700–800 K) to high (not
-
burning properties of slurry based on coal and oil Processing Waste
Energy & Fuels, 2016Co-Authors: Dmitrii O Glushkov, Sergey Yu Lyrshchikov, Sergei A Shevyrev, P A StrizhakAbstract:The main physicochemical coefficients of the components and of the tested coal–water slurry containing petrochemicals (CWSP) have been collected. The viscosity, mixture stability, density, ash content, humidity, flash and ignition temperatures, and enthalpy of combustion of the tested CWSP are reported. The temperatures of combustion of fuel compositions with different concentrations of solid and liquid components have been measured, as well as the important parameters: the ignition time delays of droplets (radius 0.25–2.5 mm) and the times required to reach their complete burning. The study allows determination of the optimal fuel compositions yielding the shortest ignition time delays, the longest times to complete burning, the highest temperatures of combustion, and the maximum enthalpy of combustion. It is found that the viscosity of CWSP is dependent almost proportionally on the moisture content of components. It is shown that the calorific value of CWSP is dependent proportionally on the calorific v...
David C. Stuckey - One of the best experts on this subject based on the ideXlab platform.
-
Utilization of Coconut Milk Processing Waste as a Low-Cost Mercury Sorbent
Industrial & Engineering Chemistry Research, 2013Co-Authors: Khairiraihanna Johari, Norasikin Saman, Hanapi Mat, Shiow Tien Song, David C. StuckeyAbstract:Desiccated coconut Waste sorbent (DCWS), a byproduct of coconut milk Processing, was studied as a sorbent for Hg(II) sorption. Energy dispersive X-ray analysis indicated that the DCWS mainly contained C, N, and O, while the Fourier transform infrared measurements confirmed the existence of hydroxyl, carboxyl, and amine groups on the DCWS surface. The point of zero charge (pHpzc) and cation-exchange capacity (CEC) values were 6.05 and 2.02 meq/100g, respectively. The batch equilibrium data were fitted well by the Langmuir isotherm model with a maximum sorption capacity, qmax of 500 mg/g, while the kinetic sorption data were found to follow a pseudo-second-order kinetic model. A column sorption study showed that the sorption capacity increased and the breakthrough time decreased with the increase in the initial Hg(II) concentrations. The regeneration studies revealed that the DCWS could be regenerated and reused.
-
Utilization of Coconut Milk Processing Waste as a Low-Cost Mercury Sorbent
2013Co-Authors: Khairiraihanna Johari, Norasikin Saman, Hanapi Mat, Shiow Tien Song, David C. StuckeyAbstract:Desiccated coconut Waste sorbent (DCWS), a byproduct of coconut milk Processing, was studied as a sorbent for Hg(II) sorption. Energy dispersive X-ray analysis indicated that the DCWS mainly contained C, N, and O, while the Fourier transform infrared measurements confirmed the existence of hydroxyl, carboxyl, and amine groups on the DCWS surface. The point of zero charge (pHpzc) and cation-exchange capacity (CEC) values were 6.05 and 2.02 meq/100g, respectively. The batch equilibrium data were fitted well by the Langmuir isotherm model with a maximum sorption capacity, qmax of 500 mg/g, while the kinetic sorption data were found to follow a pseudo-second-order kinetic model. A column sorption study showed that the sorption capacity increased and the breakthrough time decreased with the increase in the initial Hg(II) concentrations. The regeneration studies revealed that the DCWS could be regenerated and reused
Mei Wang - One of the best experts on this subject based on the ideXlab platform.
-
concentrations and patterns of polychlorinated biphenyls at different process stages of cement kilns co Processing Waste incinerator fly ash
Waste Management, 2016Co-Authors: Guorui Liu, Rong Jin, Minghui Zheng, Jiayu Zhan, Yuyang Zhao, Lili Yang, Mei WangAbstract:Cement kilns can be used to co-process fly ash from municipal solid Waste incinerators. However, this might increase emission of organic pollutants like polychlorinated biphenyls (PCBs). Knowledge of PCB concentrations and homolog and congener patterns at different stages in this process could be used to assess the possibility of simultaneously controlling emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and “dioxin-like” compounds. To date, emissions from cement kilns co-Processing fly ash from municipal solid Waste incinerators have not been analyzed for PCBs. In this study, stack gas and particulate samples from two cement kilns co-Processing Waste incinerator fly ash were analyzed for PCBs. The average total tri- to deca-chlorinated biphenyl (∑3–10PCB) concentration in the stack gas samples was 10.15 ng m−3. The ∑3–10PCB concentration ranges in particulate samples from different stages were 0.83–41.79 ng g−1 for cement kiln 1 and 0.13–1.69 ng g−1 for cement kiln 2. The ∑3–10PCB concentrations were much higher in particulate samples from the suspension pre-heater boiler, humidifier tower, and kiln back-end bag filters than in particulate samples from other stages. For these three stages, PCBs contributed to 15–18% of the total PCB, PCDD/F, and polychlorinated naphthalene toxic equivalents in stack gases and particulate matter. The PCB distributions were similar to those found in other studies for PCDD/Fs and polychlorinated naphthalenes, which suggest that it may be possible to simultaneously control emissions of multiple organic pollutants from cement kilns. Homolog patterns in the particulate samples were dominated by the pentachlorobiphenyls. CB-105, CB-118, and CB-123 were the dominant dioxin-like PCB congeners that formed at the back-end of the cement kiln. A mass balance of PCBs in the cement kilns indicated that the total mass of PCBs in the stack gases and clinker was about half the mass of PCBs in the raw materials.
Khairiraihanna Johari - One of the best experts on this subject based on the ideXlab platform.
-
Utilization of Coconut Milk Processing Waste as a Low-Cost Mercury Sorbent
Industrial & Engineering Chemistry Research, 2013Co-Authors: Khairiraihanna Johari, Norasikin Saman, Hanapi Mat, Shiow Tien Song, David C. StuckeyAbstract:Desiccated coconut Waste sorbent (DCWS), a byproduct of coconut milk Processing, was studied as a sorbent for Hg(II) sorption. Energy dispersive X-ray analysis indicated that the DCWS mainly contained C, N, and O, while the Fourier transform infrared measurements confirmed the existence of hydroxyl, carboxyl, and amine groups on the DCWS surface. The point of zero charge (pHpzc) and cation-exchange capacity (CEC) values were 6.05 and 2.02 meq/100g, respectively. The batch equilibrium data were fitted well by the Langmuir isotherm model with a maximum sorption capacity, qmax of 500 mg/g, while the kinetic sorption data were found to follow a pseudo-second-order kinetic model. A column sorption study showed that the sorption capacity increased and the breakthrough time decreased with the increase in the initial Hg(II) concentrations. The regeneration studies revealed that the DCWS could be regenerated and reused.
-
Utilization of Coconut Milk Processing Waste as a Low-Cost Mercury Sorbent
2013Co-Authors: Khairiraihanna Johari, Norasikin Saman, Hanapi Mat, Shiow Tien Song, David C. StuckeyAbstract:Desiccated coconut Waste sorbent (DCWS), a byproduct of coconut milk Processing, was studied as a sorbent for Hg(II) sorption. Energy dispersive X-ray analysis indicated that the DCWS mainly contained C, N, and O, while the Fourier transform infrared measurements confirmed the existence of hydroxyl, carboxyl, and amine groups on the DCWS surface. The point of zero charge (pHpzc) and cation-exchange capacity (CEC) values were 6.05 and 2.02 meq/100g, respectively. The batch equilibrium data were fitted well by the Langmuir isotherm model with a maximum sorption capacity, qmax of 500 mg/g, while the kinetic sorption data were found to follow a pseudo-second-order kinetic model. A column sorption study showed that the sorption capacity increased and the breakthrough time decreased with the increase in the initial Hg(II) concentrations. The regeneration studies revealed that the DCWS could be regenerated and reused
Derrick Allen - One of the best experts on this subject based on the ideXlab platform.
-
leaching behavior of mineral Processing Waste comparison of batch and column investigations
Journal of Hazardous Materials, 2008Co-Authors: Souhail R Alabed, Gautham B Jegadeesan, J Purandare, Derrick AllenAbstract:Abstract In this study, a comparison of laboratory batch and column experiments on metal release profile from a mineral Processing Waste (MPW) is presented. Batch (equilibrium) and column (dynamic) leaching tests were conducted on ground MPW at different liquid–solid ratios (LS) to determine the mechanisms controlling metal release. Additionally, the effect of pH on metal release is also discussed. It was observed that acidic pH conditions induced dissolution of As, Zn and Cu. Negligible leaching at alkaline pH was observed. However, Se depicted amphoteric behavior with high release at low and high pH. The batch and column data showed that As and Se release increased with LS ratio, while that of Cu and Zn increased initially and tapered towards equilibrium values at high LS ratios. The results on metal release from the MPW suggested that dissolution of the metal was the controlling mechanism. Leaching profiles from the batch and column data corresponded well for most LS ratios. This is most likely due to the acidic character of the Waste, minimal changes in pH during the column operation and granular structure of the Waste. From a Waste management perspective, low cost batch equilibrium studies in lieu of high cost column experiments can be used for decision making on its disposal only when the Waste exhibits characteristics similar to the mineral Processing Waste.
-
arsenic release from iron rich mineral Processing Waste influence of ph and redox potential
Chemosphere, 2007Co-Authors: Souhail R Alabed, Gautham B Jegadeesan, J Purandare, Derrick AllenAbstract:Abstract This paper presents the effect of pH and redox potential on the potential mobility of arsenic (As) from a contaminated mineral Processing Waste. The selected Waste contained about 0.47 g kg −1 of As and 66.2 g kg −1 of iron (Fe). The characteristic of the Waste was identified by acid digestion, X-ray diffraction and sequential extraction procedures. Less than 2% of the total As was acid extractable with the remaining 98% associated with Fe-oxyhydroxides and oxides. Batch leaching tests at different pH conditions showed a strong pH dependence on arsenic and iron leaching. Arsenic leaching followed a “V” shaped profiles with significant leaching in the acidic and alkaline pH region. Acid extractable phases dissolved at acidic pH, while desorption of arsenic due to increase in pH resulted in high arsenic concentration at alkaline pH. Under aerobic conditions and pH 7, As solubility was low, probably due to its precipitation on Fe-oxyhydroxides. Maximum As solubilization occurred at pH 11 (3.59 mg l −1 ). Similarity in the As and Fe leaching profiles suggested that the release of As was related to the dissolution of Fe in the low pH region. In general, redox potential did not play a significant role in arsenic or iron solubilization. It was thus concluded that for this solid Waste, desorption was the predominant mechanism in arsenic leaching. A simple thermodynamic model based on arsenic and iron redox reactions was developed to identify the more sensitive redox couple.
-
comparative evaluation of short term leach tests for heavy metal release from mineral Processing Waste
Science of The Total Environment, 2006Co-Authors: Souhail R Alabed, Gautham B Jegadeesan, Philip L Hageman, Narain Madhavan, Derrick AllenAbstract:Evaluation of metal leaching using a single leach test such as the Toxicity Characteristic Leaching Procedure (TCLP) is often questionable. The pH, redox potential (Eh), particle size and contact time are critical variables in controlling metal stability, not accounted for in the TCLP. This paper compares the leaching behavior of metals in mineral Processing Waste via short-term extraction tests such as TCLP, Field Leach Test (FLT) used by USGS and deionized water extraction tests. Variation in the extracted amounts was attributed to the use of different particle sizes, extraction fluid and contact time. In the controlled pH experiments, maximum metal extraction was obtained at acidic pH for cationic heavy metals such as Cu, Pb and Zn, while desorption of Se from the Waste resulted in high extract concentrations in the alkaline region. Precipitation of iron, caused by a pH increase, probably resulted in co-precipitation and immobilization of Cu, Pb and Zn in the alkaline pH region. A sequential extraction procedure was performed on the original Waste and the solid residue from the Eh–pH experiments to determine the chemical speciation and distribution of the heavy metals. In the as-received Waste, Cu existed predominantly in water soluble or sulfidic phases, with no binding to carbonates or iron oxides. Similar characteristics were observed for Pb and Zn, while Se existed mostly associated with iron oxides or sulfides. Adsorption/co-precipitation of Cu, Se and Pb on precipitated iron hydroxides was observed in the experimental solid residues, resulting in metal immobilization above pH 7.