Reduction Characteristic of CaSO4-CuO Combined Oxygen Carrier Under CO Atmosphere

2021 ◽  
Vol 72 (3) ◽  
pp. 122-135
Author(s):  
Kang Li ◽  
Min Zheng ◽  
Jingquan Wang ◽  
Jun Wu
Keyword(s):  
Reaction Temperature ◽  
Solid Phase ◽  
Oxygen Carrier ◽  
Reduction Reaction ◽  
Release Time ◽  
Oxygen Carriers ◽  
Main Metal ◽  
High Temperature Reaction ◽  
Caso4 Oxygen Carrier ◽  
The Individual

CaSO4 oxygen carrier is considered to be a potential oxygen carrier (OC) for Chemical Looping Combustion because of its high oxygen capacity and low price. But its reactivity is lower than the main metal oxide oxygen carriers, and it deactivates due to sulfur loss as well as sintering at high reaction temperatures above 920 ℃. To improve the performance of CaSO4-based oxygen carrier, small amounts of CuO particles were mixed mechanistically with CaSO4 particles to use as combined oxygen carrier in this work. The reduction reactions of CaSO4 oxygen carrier, CuO oxygen carrier and CaSO4-CuO combined oxygen carrier under CO atmosphere were investigated. The effects of reaction factors including reaction temperature, the oxygen-carrying ratio of CuO to CaSO4 and mass of oxygen carrier, on the reductions have been investigated in this study. XRD, SEM-EDS, BET and gas analyses were performed to investigate the variations of solid phase, element compositions in solid residual and sulfur release with reaction time. The results show that the addition of CuO increases the reactivity of the CaSO4-based oxygen carrier while also suppressing the release of the gas sulfur. For the individual reduction of CaSO4 by CO, with the increase of CaSO4 mass (500 - 1200 mg), CO2 yield also increases until 1000 mg stops and SO2 released rises remarkably; An increase in the reaction temperature aggravated the SO2 emission. The carbon dioxide generation efficiency also increases with an increase in temperature, but decreases when the temperature exceeds 950 ℃ due to sintering of the oxygen carrier particles; With respect to the reaction of CuO with CO, CO2 yield does not change significantly with increasing temperature, due to the sintering of the CuO oxygen carrier in a high temperature reaction environment;For the combined oxygen carrier: a.As the reduction reaction temperature increases, the reduction reaction performance of the combined oxygen carrier is enhanced within the reaction temperature range of 750~900℃. b. CaO the use of CuO additives not only improves the CO conversion rate, but also inhibits the release of gas sulfide. As the oxygen carrying fraction of CuO increases, SO2 released is reduced and the SO2 release time is delayed. What� more, the solid products after reduction reaction mainly contain CaS, CaO, CuO, Cu2O and CaSO4, and no copper sulfide is detected. c. When the oxygen-carrying ratio of CuO to CaSO4 is increasing from 15% to 20%, CO2 yield increases greatly.

Thermodynamic and Kinetic Analysis of Ca-Based Oxygen Carrier in Chemical-Looping Combustion

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Chang Jing ◽  
Cui Dejie
Keyword(s):  
Kinetic Analysis ◽  
Oxygen Carrier ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Calcium Sulfide ◽  
Oxygen Carriers ◽  
Thermo Gravimetric ◽  
Caso4 Oxygen Carrier ◽  
Carbon Dioxide Co2 ◽  
Gravimetric Apparatus

Chemical-looping combustion (CLC) is a promising technology to capture carbon dioxide (CO2) inherently and conveniently without the additional apparatus. At present, for some metal oxide oxygen carriers, the high costs and the positive hazards to the environment inhibit the developing of CLC systems. The feasibility of using CaSO4 oxygen carrier in the CLC system is studied in this paper. Through the thermodynamic analysis, the carbon deposition and the sulfur evolution are studied in the reaction between CaSO4 and a typical syngas. In addition, providing that hydrogen (H2) is fed as the gaseous fuel in the CLC system, the kinetic analysis is investigated on the reduction of CaSO4 by H2 and the oxidation of calcium sulfide (CaS) by oxygen (O2) through the thermo-gravimetric apparatus (TGA). The kinetic models are built on the reduction and the oxidation of the oxygen carrier. The results calculated from the models agree well with the experimental data. Finally, the possible reaction mechanisms for the reduction and the oxidation are explored.

scholarly journals Oxidation kinetics of YBaCo 4 O 7+ δ and substituted oxygen carriers

2018 ◽  
Vol 5 (6) ◽  
pp. 180150
Author(s):  
Limin Hou ◽  
Qingbo Yu ◽  
Kun Wang ◽  
Qin Qin ◽  
Mengqi Wei ◽  
...  
Keyword(s):  
Oxidation Process ◽  
Solid Phase ◽  
Oxygen Carrier ◽  
Xrd Analysis ◽  
Phase Changes ◽  
Oxygen Absorption ◽  
Oxygen Carriers ◽  
Isothermal Tg ◽  
Primary Particles ◽  
Kinetics Of

In this paper, the relaxation kinetics of the oxidation process of the YBaCo 4 O 7+ δ , Y 0.95 Ti 0.05 BaCo 4 O 7+ δ and Y 0.5 Dy 0.5 BaCo 4 O 7+ δ oxygen carriers is studied with isothermal reaction data. XRD analysis for fresh samples shows that all the samples have YBaCo 4 O 7+ δ structure. Scanning electron microscopy images of samples show that the samples consist of porous agglomerates of primary particles. Isothermal TG experiments are conducted with temperatures of 290°C, 310°C, 330°C and 350°C, respectively. It is found that the Avrami-Eroféev model describes solid-phase changes in the oxygen absorption process adequately. The results show that the distributed activation energies of the oxidation process obtained by the Avrami-Eroféev model are 42.079 kJ mol −1 , 42.944 kJ mol −1 and 41.711 kJ mol −1 for the YBaCo 4 O 7+ δ , Y 0.95 Ti 0.05 BaCo 4 O 7+ δ and Y 0.5 Dy 0.5 BaCo 4 O 7+ δ oxygen carriers, respectively. The kinetic model was obtained to predict the oxygen carrier conversion of oxygen absorption for different time durations. The kinetic parameters obtained here are quite vital when this material is used in reactors.

Research on Chemical Materials with Characteristic on Chemical Looping Combustion of Co-Doped Fe2O3 Oxygen Carrier with CO

2014 ◽  
Vol 540 ◽  
pp. 30-34
Author(s):  
Qu Li ◽  
Jing Liang ◽  
Dong Teng Long ◽  
Wei Liang Cheng ◽  
Chang Qing Dong ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Oxygen Carriers ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Thermo Gravimetric Analyzer ◽  
Conversion Time ◽  
Three Stages ◽  
Co Doped

Co-doped Fe2O3 oxygen carriers reacted with CO were investigated in order to study the temperature effect on the redox characterization.Co-Fe2O3 were characterized with X-ray diffraction (XRD), BET and transmission electron microscope (TEM), which showed that the surface structure was regular, and the polymorph was stable. The TG (Thermo Gravimetric Analyzer) analysis indicted that, rational doping Co could enhance the reactivity of iron-base oxygen carrier reacted with CO under different conditions. Oxygen carrier with Fe: Co molar ratio of 1:0.1 had best reactivity. With the temperature increased, the reduction degree became deeper and the complete conversion time shortened. The reduction reaction Co0.1Fe oxygen carrier with CO was carried out step by step, and the entire process was divided into three stages, namely 344.7-391.0, 414.7-472.5 and 607.6-681.5°C.

scholarly journals The effect of Niobium oxide as a promoter on -Al2O3 based oxygen carrier for chemical looping combustion

2021 ◽  
Vol 12 (3) ◽  
pp. 3833-3839
Author(s):  
Nur Adibah Mohd Ghazalia Et.al
Keyword(s):  
Low Cost ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Reduction Reaction ◽  
Vital Role ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Potential Candidate ◽  
Oxygen Carriers ◽  
Oxygen Transport Capacity

Chemical looping combustion (CLC) is known as a low-cost strategy for the capture of carbon dioxide for fuel combustion. In CLC process, oxygen carriers (OCs) are the cornerstone and play a vital role in defining reaction process. The aim of the present work was to investigate the potential of niobium (Nb) as a promoter on the -Al2O3 and its behavior as an oxygen carrier for chemical looping combustion process. In this work, the Nb loading was varied between 5 – 15 wt. %.  Their behavior in CLC was analyzed by TPR, TPO, SEM and TGA. From the TPR results, the reduction temperature for 5 wt.%, 10 wt.% and 15 wt.% Nb loading were 560 ℃, 529 ℃ and 545 ℃, respectively which indicated that reduction reaction occurs around 500 ℃ and above. SEM analysis showed that increasing of Nb loading resulted in some agglomeration and thus lowering the ability of metal oxide to gain and release oxygen. The redox characteristics were carried out using TGA with 5% CH4/N2 was used as the reducing gas, while air was used as oxidizing gas. The highest oxygen transfer capacity was 3.0% which is presented by 5 wt.% of Nb loading. Since the addition of Nb successfully improved the oxygen transport capacity, it can be concluded that Nb is the potential candidate for oxygen carrier in CLC.

Fully Automated Parallel Oligonucleotide Synthesizer

2001 ◽  
Vol 66 (8) ◽  
pp. 1299-1314 ◽  
Author(s):  
Michal Lebl ◽  
Christine Burger ◽  
Brett Ellman ◽  
David Heiner ◽  
Georges Ibrahim ◽  
...  
Keyword(s):  
Solid Phase ◽  
Building Blocks ◽  
Solid Support ◽  
Continuous Operation ◽  
Gear Pump ◽  
Oligonucleotide Synthesis ◽  
Center Of Rotation ◽  
Microtiter Plates ◽  
The Individual ◽  
Design And Construction

Design and construction of automated synthesizers using the tilted plate centrifugation technology is described. Wash solutions and reagents common to all synthesized species are delivered automatically through a 96-channel distributor connected to a gear pump through two four-port selector valves. Building blocks and other specific reagents are delivered automatically through banks of solenoid valves, positioned over the individual wells of the microtiterplate. These instruments have the following capabilities: Parallel solid-phase oligonucleotide synthesis in the wells of polypropylene microtiter plates, which are slightly tilted down towards the center of rotation, thus generating a pocket in each well, in which the solid support is collected during centrifugation, while the liquid is expelled from the wells. Eight microtiterplates are processed simultaneously, providing thus a synthesizer with a capacity of 768 parallel syntheses. The instruments are capable of unattended continuous operation, providing thus a capacity of over two millions 20-mer oligonucleotides in a year.

scholarly journals The Potential of Gas Switching Partial Oxidation Using Advanced Oxygen Carriers for Efficient H2 Production with Inherent CO2 Capture

2021 ◽  
Vol 11 (10) ◽  
pp. 4713
Author(s):  
Carlos Arnaiz del Pozo ◽  
Schalk Cloete ◽  
Ángel Jiménez Álvaro ◽  
Felix Donat ◽  
Shahriar Amini
Keyword(s):  
Partial Oxidation ◽  
Co2 Capture ◽  
Oxygen Carrier ◽  
H2 Production ◽  
Advanced Materials ◽  
Oxygen Carriers ◽  
Large Power ◽  
Steam Methane ◽  
Hydrogen Supply ◽  
Energy Penalty

The hydrogen economy has received resurging interest in recent years, as more countries commit to net-zero CO2 emissions around the mid-century. “Blue” hydrogen from natural gas with CO2 capture and storage (CCS) is one promising sustainable hydrogen supply option. Although conventional CO2 capture imposes a large energy penalty, advanced process concepts using the chemical looping principle can produce blue hydrogen at efficiencies even exceeding the conventional steam methane reforming (SMR) process without CCS. One such configuration is gas switching reforming (GSR), which uses a Ni-based oxygen carrier material to catalyze the SMR reaction and efficiently supply the required process heat by combusting an off-gas fuel with integrated CO2 capture. The present study investigates the potential of advanced La-Fe-based oxygen carrier materials to further increase this advantage using a gas switching partial oxidation (GSPOX) process. These materials can overcome the equilibrium limitations facing conventional catalytic SMR and achieve direct hydrogen production using a water-splitting reaction. Results showed that the GSPOX process can achieve mild efficiency improvements relative to GSR in the range of 0.6–4.1%-points, with the upper bound only achievable by large power and H2 co-production plants employing a highly efficient power cycle. These performance gains and the avoidance of toxicity challenges posed by Ni-based oxygen carriers create a solid case for the further development of these advanced materials. If successful, results from this work indicate that GSPOX blue hydrogen plants can outperform an SMR benchmark with conventional CO2 capture by more than 10%-points, both in terms of efficiency and CO2 avoidance.

scholarly journals Can the decrease of blood alcohol level be accelerated? Results of a clinical study

2009 ◽  
Vol 150 (19) ◽  
pp. 903-907 ◽  
Author(s):  
Mária Mátyus ◽  
István Horváth ◽  
János Fehér ◽  
Róbert Farkas ◽  
Veronika Wolf ◽  
...  
Keyword(s):  
Solid Phase ◽  
Blood Alcohol Level ◽  
Gas Chromatography Mass Spectrometry ◽  
Blood Alcohol ◽  
Alcohol Metabolism ◽  
Experimental Protocol ◽  
Spectrometry Method ◽  
Pure Alcohol ◽  
Guardian Angel ◽  
The Individual

The purpose of this study was to examine the effect of Guardian Angel powder (GA) on the blood alcohol level. According to the experimental protocol, two sets of measurement were performed: modeling the eating and drinking habit of a typical family or social meeting, alcohol containing drinks corresponding to 70 g of pure alcohol and copious amount of food were consumed first without GA powder, then with GA powder. In the latter case GA powder was dissolved in water and one dose was taken before eating, the other one was consumed during eating. Blood samples were hourly collected from the volunteers in both sets for four hours. The measurement of blood alcohol level was performed by gas chromatography-mass spectrometry method proceeding to Solid Phase Micro Extraction (SPME). Our results show that the blood alcohol level decreased significantly when two doses of GA powder were consumed. After two hours of taking GA powder, the blood alcohol level was significantly lower in each volunteers compared to their own blood alcohol level measured in the absence of GA powder. This result shows that the individual variation of the alcohol metabolism does not influence significantly the effect of GA powder. Further studies are needed to investigate the detailed mechanism of the action of GA powder to find out whether GA powder influences the absorption of alcohol or/and the metabolism of alcohol.

An Optical Model for Quantitative Raman Microspectroscopy

2020 ◽  
Vol 74 (6) ◽  
pp. 684-700 ◽  
Author(s):  
Joseph Razzell Hollis ◽  
David Rheingold ◽  
Rohit Bhartia ◽  
Luther W. Beegle
Keyword(s):  
Optical Model ◽  
Solid Phase ◽  
Pyrolytic Graphite ◽  
Sample Volume ◽  
Raman Intensity ◽  
Complex Samples ◽  
Uniform Sample ◽  
Pass Through ◽  
The Individual ◽  
Spectrometer Slit

Raman spectroscopy is an invaluable technique for identifying compounds by the unique pattern of their molecular vibrations and is capable of quantifying the individual concentrations of those compounds provided that certain parameters about the sample and instrument are known. We demonstrate the development of an optical model to describe the intensity distribution of incident laser photons as they pass through the sample volume, determine the limitations of that volume that may be detected by the spectrometer optics, and account for light absorption by molecules within the sample in order to predict the total Raman intensity that would be obtained from a given, uniform sample such as an aqueous solution. We show that the interplay between the shape and divergence of the laser beam, the position of the focal plane, and the dimensions of the spectrometer slit are essential to explaining experimentally observed trends in deep ultraviolet Raman intensities obtained from both planar and volumetric samples, including highly oriented pyrolytic graphite and binary mixtures of organic nucleotides. This model offers the capability to predict detection limits for organic compounds in different matrices based on the parameters of the spectrometer, and to define the upper/lower limits within which concentration can be reliably determined from Raman intensity for such samples. We discuss the potential to quantify more complex samples, including as solid phase mixtures of organics and minerals, that are investigated by the unique instrument parameters of the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) investigation on the upcoming Mars 2020 rover mission.

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