Study of Modified Dry Desulfurization Ash in a Power Plant for Sequestering CO2 from a Micron-Nanoscale Perspective

2021 ◽  
Vol 21 (1) ◽  
pp. 382-391
Author(s):  
Jieying Cai ◽  
Xiangdong Li ◽  
Di Chen ◽  
Qiyan Feng
Keyword(s):  
Carbon Sequestration ◽  
Initial Pressure ◽  
Kinetics Equation ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
X Ray ◽  
First Order ◽  
First Order Kinetics ◽  
Before And After ◽  
Solid Liquid

To improve the CO2 fixation ability of dry desulfurization ash (DDA), a DDA must be modified by chemical methods. At the micron level, the changes in microstructure and chemical composition before and after DDA modification were analysed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS), and the reaction mechanism of the modification process was inferred. On the other hand, the chemical and mineral phase compositions of the modified DDA and its solid products were analysed by X ray Fluorescence (XRF) and X-ray diffraction (XRD). In addition, the microstructure of the modified DDA before and after sequestration at nanometre resolution was studied by SEM-EDS so that the curing mechanism of the modified DDA was clearly defined. Then, the effects of the solid–liquid ratio, temperature, pressure and reaction time on the sequestration of CO2 in the modified DDA were studied with aqueous carbonation. The results showed that the higher the temperature is, the higher the solid–liquid ratio, and the lower initial pressure is, the less the CO2 sequestered in the modified DDA and the less the carbon sequestration capacity of the modified DDA. Under the experimental conditions, the carbonation efficiency of the modified DDA could reach 94.42%, and 1 ton of modified DDA could sequester up to 50.61 kg CO2. Compared with conventional DDA, the carbon sequestration capacity is effectively improved. The kinetic data confirmed that the fitting correlation of the quasi-first-order kinetics equation is more significant. The smaller the solid–liquid ratio is, the lower the temperature, the higher the initial pressure, and the higher the rate constant of the quasi-first-order kinetics equation.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

Effect of thiol oxidation and thiol export from erythrocytes on determination of redox status of homocysteine and other thiols in plasma from healthy subjects and patients with cerebral infarction

1995 ◽  
Vol 41 (3) ◽  
pp. 361-366 ◽  
Author(s):  
A Andersson ◽  
A Lindgren ◽  
B Hultberg
Keyword(s):  
Cerebral Infarction ◽  
Healthy Subjects ◽  
Redox Status ◽  
Reduced Form ◽  
Temperature Dependent ◽  
First Order ◽  
First Order Kinetics ◽  
Before And After ◽  
Reduced Forms

Abstract Changes in concentration of reduced and oxidized low-M(r) thiols were measured in blood and plasma before and after the separation of blood cells. If centrifugation of blood was postponed, the reduced form of homocysteine in plasma increased with time at 22 degrees C; in contrast, the concentrations of other reduced thiols (cysteine, glutathione, and cysteinylglycine) decreased. In plasma the reduced forms of all thiols disappeared at a rate that followed first-order kinetics. The rates of disappearance ("half-lives") were temperature-dependent; they were about the same for glutathione and homocysteine (11.7 and 14.3 min, respectively, at 22 degrees C) and somewhat higher for cysteinylglycine and cysteine. After establishing proper sampling conditions for reduced thiols, we measured this thiol fraction as well as free (non-protein-bound) and total thiols in 10 reference subjects and 19 patients with cerebral infarction. Mild but significant hyperhomocysteinemia involving total and free homocysteine (but not reduced homocysteine) was found in the patients.

scholarly journals β-Cyclodextrin Modified Poly(Acrylonitrule-co-Acrylic Acid) Hydrogel for Thorium(IV) Adsorption

Polymers ◽  
2017 ◽  
Vol 9 (6) ◽  
pp. 201 ◽  
Author(s):  
Guojian Duan ◽  
Qiangqiang Zhong ◽  
Lei Bi ◽  
Liu Yang ◽  
Tonghuan Liu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Water System ◽  
Maximum Adsorption Capacity ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

In this report, the β-CD(AN-co-AA) hydrogel was used to remove the thorium(IV) [Th(IV)] from the water system, and the new adsorbent was characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The influences of contact time, pH value, ionic strength, solid-liquid ratio, initial Th(IV) concentration, and temperature on Th(IV) adsorption onto the functional hydrogel were researched. The results showed that the experimental data followed the Langmuir isotherm and the maximum adsorption capacity (qmax) for Th(IV) was 692 mg/g at pH 2.95, which approached the calculated (qe) 682 mg/g. The desorption capacity of Th(IV) in different HNO3 concentrations ranging from 0.005 to 0.5 M was also studied, and the percentage of the maximum desorption was 86.85% in the condition of 0.09 M HNO3. The selectivity of β-CD(AN-co-AA) hydrogel was also be studied, the results indicated that this material retained the good adsorption capacity to Th(IV) even when the Ca2+, Mg2+, or Pb2+ existed in the system. The findings indicate that β-CD(AN-co-AA) can be used as a new candidate for the enrichment and separation of Th(IV), or its analogue actinides, from large-volume solution in practical application.

Wet-Purification of a Sodium-Based Bentonite

2013 ◽  
Vol 743-744 ◽  
pp. 692-696
Author(s):  
Shui Lin Zheng ◽  
Yang Yang Huai ◽  
Zhen Wei Li ◽  
Hao Ran Cui ◽  
Zhi Ming Sun
Keyword(s):  
Methylene Blue ◽  
Diffraction Analysis ◽  
Purification Process ◽  
X Ray Diffraction ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Bentonite mainly consists of montmorillonite, but is always associated with other impure minerals. In order to increase the montmorillonite content in raw bentonite from Xinjiang, this paper adopts wet-purification process which integrates the scrubbing process with streamlined centrifugalization. The optimum experiment condition is solid - liquid ratio (wv) 130, macerating time 20h, scrubbing time 10min, centrifugation time 13min, centrifugation velocity 1260r/min, ZHL dosage 0.4% and ZHC dosage 0.4%. According to the amount of methylene blue absorption raising from 64.5mmol/100g to 110mmol/100g and X-ray diffraction analysis, the montmorillonite content raises from 48% to 82%.

scholarly journals Photoperoxidation of ciprofloxacin antibiotic in aqueous medium using Fe3-XO4-Y-TiO2 particles as catalyst

2022 ◽  
Vol 47 (1) ◽  
pp. 55-63
Author(s):  
Ismael Laurindo Costa Junior ◽  
Kevin Augusto Ferreira ◽  
Cesar Augusto Kappes ◽  
Renata Mello Giona
Keyword(s):  
Conventional Treatment ◽  
H2o2 Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Tio2 Particles ◽  
Treatment Processes ◽  
First Order Kinetics ◽  
Heat Treated ◽  
Oxidative Processes

Conventional treatment processes are not effective in removing micropollutants such as antibiotics and other drugs present in wastewater, and degradation methods based on advanced oxidative processes become attractive. Herein, it was synthesized Fe3-xO4-y-TiO2 particles by coprecipitation method and they were heat-treated at 100, 400, and 800 �C. The obtained solids were characterized by X-ray diffraction and thermogravimetric analysis and analytical determinations were performed using ultraviolet-visible (UV-Vis) spectrophotometry. The particles were evaluated in photoperoxidation processes on the degradation of the ciprofloxacin antimicrobial in an aqueous solution. The studies took place at pH 9; with an H2O2 concentration of 31 mg L�1 and particle mass 0.22 g L�1 previously defined and, in these conditions, degradation percentages between 40 and 85% were observed, with the removal in the Photo/H2O2/Fe3-xO4-y-TiO2 800 �C. The kinetic study performed for this process revealed the process adjusts to the first-order kinetics during the 120 min of reaction. The use of the catalyst can be attractive with the potential for degradation of the studied antimicrobial.

Salicylate Kinetics In The Rat: Relationship To Antithrombotic Activity

1981 ◽  
Author(s):  
R B Philp ◽  
I Francey
Keyword(s):  
Carotid Arteries ◽  
Post Injection ◽  
Antithrombotic Effect ◽  
Protective Level ◽  
Antithrombotic Activity ◽  
First Order ◽  
First Order Kinetics ◽  
Salicylate Level ◽  
Before And After ◽  
Prostacyclin Synthesis

Recently we reported that acetylsalicylic acid (ASA) 100 mg/kg i.v. had no antithrombotic effect in a rat model of arterial thrombosis whereas 200 mg/kg i.v. had significant antithrombotic activity. The present study investigates salicylate kinetics at the non-protective level. Carotid arteries of urethane-anesthetized rats were injured electrically (1 mA, DC, for 1 min) and thrombogenesis measured by recording downstream temperature. Right and left side injuries were compared before and after ASA, 100 mg/kg i.v. Blood samples were collected at various times post injection and serum assayed for salicylate content by Trinder’s method. All salicylate levels are reported as mg/dL ± SEM. Control injuries produced a temperature fall of 1.4°C ± 0.08 (SEM) and post ASA injuries a fall of 1.8°C ± 0.17 (SEM) (P < .1 > .05). Serum salicylate was 20 mg ± 4.58 1 min post injection and the calculated lh was 40 min with decay following first order kinetics. The intraperitoneal injection of ASA 200 mg/kg produced a serum salicylate level of 8.1 ± 1.55 5 min post injection with a peak of 19 ± 2.03 30 min post injection. Both absorption and elimination followed first order kinetics with Th values of 10 and 44 min respectively. Urine collected 40 min post injection contained 9.4 ± 3.38 free salicylate which increased to about 40 following chemical digestion, indicating the presence of metabolites. The results indicate that serum salicylate levels < 20 do not offer antithrombotic protection in this model and that this level is achieved only briefly following ASA 100 mg/kg i.v. or 200 mg/kg i.p. The brief half-life of ASA in the rat has implications for the interpretation of data concerning the inhibition of prostacyclin synthesis by vessel wall. The wide variation in effective ASA doses reported for various animal models of thrombosis is probably a function of the nature of the model rather than of efficient prostacyclin synthesis.

scholarly journals From lapis lazuli to ultramarine blue: investigating Cennino Cennini’s recipe using sulfur K-edge XANES

2018 ◽  
Vol 90 (3) ◽  
pp. 463-475 ◽  
Author(s):  
Monica Ganio ◽  
Emeline S. Pouyet ◽  
Samuel M. Webb ◽  
Catherine M. Schmidt Patterson ◽  
Marc S. Walton
Keyword(s):  
Prolonged Exposure ◽  
Purification Process ◽  
X Ray ◽  
First Order ◽  
Ultramarine Blue ◽  
First Order Kinetics ◽  
Blue Component ◽  
Rosin Gum ◽  
Ultramarine Pigments ◽  
Lapis Lazuli

AbstractAs one of the most desired and expensive artists’ materials throughout history, there has long been interest in studying natural lapis lazuli. The traditional method of extracting the blue component, lazurite, from lapis lazuli, as outlined in Cennini’sIl Libro dell’Arte, involves a lengthy purification process: (1) finely grind the rock; (2) mix with pine rosin, gum mastic, and beeswax; (3) massage in water to collect the lazurite. Repeating the process produces several grades of the pigment, typically referred to as ultramarine blue. Here, we investigate the sulfur environment within the aluminosilicate framework of lazurite during its extraction from lapis lazuli. The sulfur XANES fingerprint from samples taken at the different stages in Cennini’s extraction method were examined. All spectra contain a strong absorption peak at 2483 eV, attributable to sulfate present in the lazurite structure. However, intensity variations appear in the broad envelope of peaks between 2470 and 2475 eV and the pre-peak at 2469.1 eV, indicating a variation in the content of trisulfur (S3−˙) radicals. By studying the effect of each step of Cennini’s process, this study elucidates the changes occurring during the extraction and the variability within different grades of the precious coloring material. The increasing application of XANES to the study of artist’s materials and works of art motivated extending the research to assess the possibility of X-ray induced damage. Direct comparison of micro-focused and unfocused beam experiments suggests an increase of the S3−˙ radicals with prolonged exposure. Analysis indicates that induced damage follows first-order kinetics, providing a first assessment on the acceptable amount of radiation exposure to define the optimal acquisition parameters to allow safe analyses of lapis lazuli and ultramarine pigments.

Thermal Degradation of Green Asparagus Texture

1997 ◽  
Vol 60 (3) ◽  
pp. 315-320 ◽  
Author(s):  
CARMEN RODRIGO ◽  
MIGUEL RODRIGO ◽  
SUSANA FISZMAN ◽  
TERESA SÁNCHEZ
Keyword(s):  
Single Point ◽  
Experimental Conditions ◽  
Cutting Resistance ◽  
First Order ◽  
First Order Kinetics ◽  
Press Method ◽  
The Wire ◽  
Shear Press ◽  
Kinetics Of ◽  
Green Asparagus

A cutting cell was developed to evaluate the texture of green asparagus by measuring its resistance to being cut with a wire. The cell was used in conjunction with a universal texturometer and improved on the single-point method of the Wilder fibrometer. Experimental conditions were determined for using the cell to measure the cutting resistance of asparagus subjected to different extents of heat treatment. Better discrimination between samples was obtained than with a Kramer cell. The fresh asparagus spears. were heated at temperatures between 70 and 100°C for different lengths of time and the kinetics of the degradation of texture was studied. A biphasic (two-component) behavior was observed with each component displaying first-order kinetics, The kinetic parameters calculated by measuring the texture with the wire cell (cutting at a position 5 em from the tip of the asparagus) were Eaa = 9.56 and Eab = 20.43 kcal/mol (activation energy for components A and B), and ka85 = 1.047 and kb85 = 0.057 min−1 (rate constants for A and B of asparagus heated at 85°C). When the texture was determined by measuring the shear force with a Kramer cell, the parameters estimated were Eaa = 23.41 and Eab = 18.32 kcal/mol, and ka85 = 0.25 and kb85 = 0.025 min−1 Both the wire cell cutting method and the Kramer shear-press method are suitable for evaluating the degree of thermal softening of green asparagus heated to temperatures between 70 and 100°C.

Über die Abnahme von Elektronenzentren in 60Co-γ-bestrahltem polykristallinem NaCl bei Adsorption von Gasen

1969 ◽  
Vol 24 (5) ◽  
pp. 796-802 ◽  
Author(s):  
J. R. Rabe ◽  
G. Joppien
Keyword(s):  
Sodium Chloride ◽  
Ionizing Radiation ◽  
Nitrogen Molecule ◽  
Color Centers ◽  
Experimental Conditions ◽  
Adsorbed Molecules ◽  
First Order ◽  
First Order Kinetics ◽  
Adsorption Of Gases

Abstract Ionizing radiation generates color centers in sodium chloride. On adsorption of gases on preir-radiated salt the concentration of electron centers decreases. Adsorbed azoethane partly decomposes forming nitrogen. About one to five electron centers disappear per nitrogen molecule formed depending on experimental conditions (temperature, amount of azoethane adsorbed and pretreatment of the salt). Electron centers disappear and nitrogen is formed with identical rates following first order kinetics. It is suggested that adsorbed molecules interacting with the surface cause electrons or holes to escape from their traps and eventually to recombine.

Macrokinetics and Mechanism of Phenol Solution Degradated by Fe3+/Ce4+ Doped TiO2 Particles

2014 ◽  
Vol 955-959 ◽  
pp. 411-414
Author(s):  
Yu Fei Wang ◽  
Long Yan ◽  
Jian Li
Keyword(s):  
Degradation Process ◽  
Isobutyric Acid ◽  
Phenol Solution ◽  
First Order ◽  
Degradation Reactions ◽  
First Order Kinetics ◽  
Before And After ◽  
Mechanism Of Degradation ◽  
Butanedioic Acid ◽  
Dynamic Cycle

Fe3+/Ce4+doped TiO2particles was prepared and used for degradation of phenol solution, the macrokinetics and mechanism of degradation process was proposed by GC-MS, and Fe3+/Ce4+-doped TiO2particles before and after treated phenol was also compared by TEM. The experimental results showed that COD degradation reactions in static and dynamic cycle process are in accordance with first-order kinetics from the macro effects, phenol can be oxidized to intermediates, such as isobutyric acid, malonic acid, para-benzoquinone, butenic acid, ethanedioic acid, maleic acid, butanedioic acid, o-dihydroxybenzene, paradioxybenzene and dioxybenzene, indicating that Fe3+/Ce4+-doped TiO2particles are beneficial to some oxidation formation. Moreover, the shapes of Fe3+/Ce4+-doped TiO2particles after treated phenol displays aggregated.

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