Dependence of Corrosion Process Rate on Carbon Dioxide Medium Containing Flow Rate

2021 ◽  
Author(s):  
R. K. Vagapov ◽  
I. S. Tomskiy
Keyword(s):  
Carbon Dioxide ◽  
Flow Rate ◽  
Corrosion Process ◽  
Process Rate

Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

2018 ◽  
Author(s):  
Jinlan Gou ◽  
Wei Wang ◽  
Can Ma ◽  
Yong Li ◽  
Yuansheng Lin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Brayton Cycle ◽  
Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

High Flue Gas Flow Rate Tests for Removal and Recovery of Carbon Dioxide under Power Plant Effluent Gas Conditions

2004 ◽  
Vol 30 (6) ◽  
pp. 758-761
Author(s):  
Tomio MIMURA ◽  
Yasuyuki YAGI ◽  
Masaki IIJIMA ◽  
Ryuji YOSIYAMA ◽  
Takahito YONEKAWA
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Power Plant Effluent ◽  
Removal And Recovery

scholarly journals NILAI TAMBAH MINYAK AKAR WANGI DENGAN PEMEKATAN KADAR VETIVEROL MENGGUNAKAN EKSTRAKSI CO2 FLUIDA SUPERKRITIK

2014 ◽  
Vol 16 (2) ◽  
pp. 76-81 ◽  
Author(s):  
Anny Sulaswatty ◽  
Egi Agustian
Keyword(s):  
Carbon Dioxide ◽  
Refractive Index ◽  
Specific Gravity ◽  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Flow Rate ◽  
Optical Rotation ◽  
Process Conditions ◽  
Fluid Extraction ◽  
Great Opportunity

Potensi Indonesia akan minyak akar wangi yang berorientasi ekspor dalam industri kosmetik, parfum, sabun, keperluan terapi, antiseptik, massage oil, farmasi dan pestisida memberikan peluang yang besar untuk memenuhi kebutuhan dunia. Guna nilai tambah minyak akar wangi dengan meningkatkan kadar vetiverol sebagai komponen utama, diaplikasikan teknologi ekstraksi fluida karbondioksida superkritik yang merupakan perpaduan ekstraksi, fraksinasi dan deodorisasi dengan didukung keunggulan karbondioksida sebagai pelarut yang inert, ramah lingkungan, mudah dipisahkan, dan berdaya larut tinggi.  Minyak akar wangi Garut (Java vetiver oil) sebagai bahan baku, mempunyai karakteristik  kadar vetiverol  39.03 %; Bobot jenis 0.9977; indeks bias 1.5247;  putaran optik +38.1; kelarutan dalam alkohol 95%  yaitu 1:1 jernih; bilangan asam 28.1; bilangan ester 24.6; bilangan ester setelah asetilasi 115.5; serta tidak mengandung minyak lemak dan  minyak keruing. Pemilihan kondisi proses guna menghasilkan kandungan vetiverol optimal dilakukan dengan memvariasikan laju alir gas CO2, tekanan dan suhu sebagai parameter penting dalam keberhasilan proses ekstraksi minyak akar wangi dengan fluida CO2 superkritik. Pemilihan laju alir konstan dan lebih stabil  diperoleh pada 5.5 liter/menit, sedangkan untuk variasi tekanan ekstraktor (1500, 1750, 2000 psi) dan suhu ekstraktor (40-50oC);  tekanan dan suhu separator  500 psi dan 25oC serta waktu proses selama lima jam dengan pengambilan ekstrak setiap jam. Tekanan dan suhu proses yang optimal diperoleh pada 1750 psi dan suhu 40oC  dengan  rafinat minyak akar wangi berkadar vetiverol  51.82 %,  bilangan ester 7.2 dan bilangan ester setelah asetilasi  172.4. Tingginya tekanan dan rendahnya suhu berpengaruh terhadap perolehan ekstrak; penurunan rafinat; peningkatan nilai  bobot jenis ekstrak dan rafinat; indeks bias ekstrak dan rafinat; putaran optik ekstrak dan rafinat; peningkatan viskositas ekstrak dan rafinat; peningkatan bilangan ester ekstrak, bilangan ester setelah asetilasi ekstrak, serta kandungan vetiverol.Kata Kunci: Minyak Akar Wangi, Vetiverol, Ekstraksi Fluida Superkritik Potential Indonesian vetiver oil export oriented industry of cosmetics, perfumes, soaps, therapeutic purposes, antiseptic, massage oil, pharmaceutical and pesticide presents a great opportunity to meet the needs of the world. In order to add value vetiver oil by increasing the levels vetiverol as the main component, was applied to carbon dioxide supercritical fluid extraction technology which is a combination of extraction, fractionation and deodorization with excellence supported carbon dioxide as an inert solvent, eco-friendly, easily separated, and the high solubility. Garut vetiver oil (Java vetiver oil) as raw material, has the characteristics vetiverol levels 39.03%, specific gravity of 0.9977; refractive index of 1.5247; optical rotation +38.1; solubility in alcohol 95% is a clear 1:1; acid number 28.1; ester number 24.6; ester number after acetylation 115.5; as well as fats and oils contain no oil keruing. The selection process conditions in order to produce optimal vetiverol content performed by varying the flow rate of CO2 gas, pressure and temperature as an important parameter in the success of vetiver oil extraction with supercritical CO2 fluid. The selection of a constant flow rate and more stable obtained at 5.5 liters / min, whereas for pressure variation extractor (1500-2000 psi) and extractor temperature (40-50oC); separator pressure and temperature of 500 psi and 25 °C as well as the processing time for five hours by taking extracts every hour. Pressure and temperature optimum process obtained at 1750 psi and a temperature of 40oC with rafinat vetiverol vetiver oil yield of 51.82%, ester number 7.2, and ester number after acetylation 172.4. The high pressure and low temperature affect the acquisition of the extract; rafinat decline; increase in the value of specific gravity and rafinat extracts; refractive index and rafinat extract; optical rotation and rafinat extract; increase in the viscosity of the extract and rafinat; increase in numbers ester extract, ester number after acetylation extracts, as well as the content vetiverol. Key word: Vetiver Oil, Vetiverol, Supercritical Fluid Extraction.

scholarly journals Extraction of essential oils from lime (Citrus latifolia Tanaka) by hydrodistillation and supercritical carbon dioxide

2005 ◽  
Vol 48 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Ana Cristina Atti-Santos ◽  
Marcelo Rossato ◽  
Luciana Atti Serafini ◽  
Eduardo Cassel ◽  
Patrick Moyna
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Essential Oils ◽  
Flow Rate ◽  
Plant Material ◽  
Supercritical Extraction ◽  
Extraction Time ◽  
Citrus Latifolia ◽  
Co2 Flow ◽  
Supercritical Carbon

In this work lime essential oils were extracted by hydrodistillation and supercritical carbon dioxide. In the case of hydrodistillation, the parameters evaluated were extraction time and characteristics of the plant material. In supercritical extraction, the parameters evaluated were temperature, pressure, CO2 flow, extraction time and material characteristics. Considering citral content, the best results for hydrodistillation were obtained with a distillation time of 3 hours using whole peels. The best results for supercritical extraction were found using 60ºC, 90 bar, at a CO2 flow rate of 1 mL/ min for 30 minutes using milled peels. The best yields of lime oil were obtained by hydrodistillation (5.45% w/w) and supercritical extraction (7.93% w/w) for milled peels.

Numerical Performance and Flow Field Study of Centrifugal Compressor With Supercritical Carbon-Dioxide (SCO2)

2019 ◽  
Author(s):  
Hemant Kumar ◽  
Chetan S. Mistry
Keyword(s):  
Carbon Dioxide ◽  
Thermodynamic Properties ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Compressor Inlet

Abstract The Supercritical carbon-dioxide Brayton cycle main attraction is due to the Supercritical characteristic of the working fluid, carbon-dioxide (SCO2). Some of the advantages of using SCO2 are relatively low turbine inlet temperature, the compression work will be low, and the system will be compact due to the variation of thermodynamic properties (like density, and specific heat ratio) of SCO2 near the critical point. SCO2 behave more like liquid when its state is near the critical point (Total Pressure = 7.39 MPa, Total Temperature = 305 K), operating compressor inlet near critical point can minimize compression work. For present study the centrifugal compressor was designed to operate at 75,000 rpm with pressure ratio (P.R) = 1.8 and mass flow rate = 3.53 kg/s as available from Sandai report. Meanline design for centrifugal compressor with SCO2 properties was done. The blade geometry was developed using commercial CAD Ansys Bladegen. The flow domain was meshed using Ansys TurboGrid. ANSYS CFX was used as a solver for present numerical study. The thermodynamic properties of SCO2 were imported from the ANSYS flow material library using SCO2.RPG [NIST thermal physics properties of fluid system]. In order to ensure the change in flow physics the mesh independence study was also conducted. The present paper discuss about the performance and flow field study targeting different mass flow rates as exit boundary condition. The comparison of overall performance (Pressure Ratio, the Blade loading, Stage efficiency and Density variation) was done with three different mass flow rates. The designed and simulated centrifugal compressor meets the designed pressure rise requirement. The variation of mass flow rate on performance of centrifugal compressor was tend to be similar to conventional centrifugal compressor. The paper discusses about the effect of variation in density, specific heat ratio and pressure of SCO2 with different mass flow outlet condition. The performance map of numerical study were validated with experiment results and found in good agreement with experimental results. The change in flow properties within the rotor flow passage are found to be interesting and very informative for future such centrifugal compressor design for special application of SCO2 Brayton cycle. 80% mass flow rate has given better results in terms of aerodynamic performance. Abrupt change in thermodynamic properties was observed near impeller inlet region. Strong density variations are observed at compressor inlet.

scholarly journals Comparison in Spontaneous Ventilation of the Maxima with the Humphrey ADE Breathing System and between Four Methods for Detecting Rebreathing

1995 ◽  
Vol 23 (3) ◽  
pp. 296-301 ◽  
Author(s):  
D. M. Miller ◽  
A. Palm
Keyword(s):  
Carbon Dioxide ◽  
Flow Rate ◽  
Qualitative Method ◽  
Gas Flow ◽  
Breathing System ◽  
Practical Application ◽  
Efferent Limb ◽  
Clinical Methods ◽  
Significant Difference ◽  
Reservoir Systems

An enclosed efferent, afferent reservoir breathing system (Maxima, Life Air Pty Ltd), being valveless, was compared to a simple afferent reservoir system (Humphrey ADE, A mode), having a valve, by assessing fresh gas flow (V̇F) requirements, with respect to ventilation (V̇E), that prevents rebreathing in volunteers, awake and breathing spontaneously. The results are recorded in terms of the quotient V̇F/V̇E associated with the onset of rebreathing. At the same time four clinical methods for assessing rebreathing were evaluated from the perspective of suitability for practical application during anaesthesia. No significant difference was found in the VF requirements between the ADE and Maxima breathing systems with respective values obtained for the quotient VF/VE of 0.80 and 0.77. Our findings showed that the method of sampling carbon dioxide (CO2) at the outflow of the efferent limb of the patient connector (eliminated CO2 method) in both afferent reservoir systems provided the highest flow rate and most reliable indication for detecting potential or actual rebreathing, when attempting to minimize VF. It provides no additional deadspace or resistance to gas flow, and has the advantage of being the only qualitative method that is reliable for the purpose of detecting the onset of rebreathing.

scholarly journals Formation of Polyethylene Glycol Particles Using a Low-Temperature Supercritical Assisted Atomization Process

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2235
Author(s):  
Hsien-Tsung Wu ◽  
Hong-Ming Tsai ◽  
Tsung-Hsuan Li
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Low Temperature ◽  
Flow Rate ◽  
Fine Particles ◽  
Volumetric Flow Rate ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Rate Ratios

Polyethylene glycol (PEG) particles were prepared using low-temperature supercritical assisted atomization (LTSAA) with carbon dioxide as the spraying medium or the co-solute and acetone as the solvent. The effects of several key factors on the particle size were investigated. These factors included the concentration of the PEG solution, precipitator temperature, saturator temperature, ratio of the volumetric flow rate of carbon dioxide to the PEG solution, and the molecular weight of PEG. Spherical and non-aggregated PEG particles, with a mean size of 1.7–3.2 µm, were obtained in this study. The optimal conditions to produce fine particles were found to be a low concentration of the PEG solution, a low precipitator temperature, and low molecular weight of the PEG. The phase behavior of the solution mixture in the saturator presented a qualitative relationship. At the optimized volumetric flow rate ratios, the composition of CO2 in the feed streams was near the bubble points of the saturator temperatures. X-ray and differential scanning calorimetry analyses indicated that LTSAA-treated PEG had a reduced degree of crystallinity, which could be modulated via the precipitator temperature. PEG microparticles prepared by a LTSAA process would be promising carriers for drug-controlled formulations of PEG-drug composite particles.

Corrosion Analysis of Copper Tubes in the Exchangers with the Assistance of Atom Absorption Spectroscopy

2013 ◽  
Vol 378 ◽  
pp. 275-279
Author(s):  
Hao Zhang ◽  
Yuan Sheng Lin ◽  
Ke Long Zhang ◽  
Zhi Guo Wei ◽  
Wei Wei Wang
Keyword(s):  
Carbon Dioxide ◽  
Dissolve Oxygen ◽  
Absorption Spectroscopy ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Working Condition ◽  
Corrosion Process ◽  
Advantages And Disadvantages ◽  
Working Media ◽  
Atom Absorption

Copper was always used as the tube materials of heat exchangers because of its superior thermal performance. The working condition of the pipes played an important role in the corrosion process. Copper would be eroded by the dissolve oxygen and carbon dioxide in water. In this manuscript, the corrosion factors inside the heat exchangers were analyzed. Besides, atom absorption spectroscopy (AAS) was introduced and used to detect copper in the working media of two exchangers. Advantages and disadvantages of AAS were discussed.

Experimental Study of the Reforming of Methane with Carbon Dioxide over Coal Char

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Yanbing Li ◽  
Rui Xiao ◽  
Baosheng Jin ◽  
Huiyan Zhang
Keyword(s):  
Carbon Dioxide ◽  
Flow Rate ◽  
Fixed Bed ◽  
Coke Oven ◽  
Fixed Bed Reactor ◽  
Internal Diameter ◽  
Generation System ◽  
Coke Oven Gas ◽  
Surface Areas ◽  
Conversion Of Methane

As one of the fundamental issues of the new poly-generation system on the basis of gasification gas and coke oven gas, carbon dioxide reforming of methane experiments have been performed over coal chars derived from different parent coals in a lab-scale fixed-bed reactor (internal diameter 12 mm, length 700 mm). The char derived from TongChuan coal exhibited higher activity than other samples employed under the same conditions. After the reforming reaction, the char samples were covered with different amounts of carbon deposition which resulted in the surface areas decrease. As the flow rate of feed gas increased from 200 ml/min to 600 ml/min over the Xuzhou char sample at 1050 degrees Celsius, the conversion of methane decreased from 52.7% to 17.5% and the H2 /CO dropped from 0.75 to 0.55. While maintaining the flow rate of CO2 at 20ml/min at 1050 degrees Celsius, the mole ratio of reactants CH4/CO2 was varied from 1 to 1.75 which led to the H2/CO ratio increase from 0.75 to 1.2.

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