Papers by Keyword: Carbon Dioxide CO2

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Authors: Ming Wen, Ce Zhang
Abstract: This document deals with the study of a carbon dioxide detector, which is used in survivors searching in earthquake ruins. In order to find the carbon dioxide of exhaled gases of earthquake survivors in the narrow space, we compared the different types of carbon dioxide sensors. At last, we selected the infrared sensors, which direct access to digital signals through the microcontroller, and has a temperature compensation function. The result of measuring was displayed in a vacuum fluorescent displayer. When it achieves the preset value, the sound and light alarm will be triggered. The test results show that the detector is fit for narrow space survivors search.
Authors: Gang Qin, Li Dan Fan, Rui Zhang, Shao Kui Cao
Abstract: A catalyst of BTPD-Zn (BTPD= N,N’-Bis(2-thiophenecarboxaldehy) o-phenylenediamine) has been found to be active toward the copolymerization of cyclohexene oxide and carbon dioxide, and a kind of good biodegradable material named poly(cyclohexene carbonate) is prepared with turnover number of 105.8 in 100°C. The molar fraction (fc) of polycarbonate in copolymer is 96%. The obtained copolymers were characterized by IR and NMR.
Authors: Zhi Jia Huang, Xiao Ding, Hao Sun, Si Yue Liu
Abstract: The amount of CO2 emissions from steelworks accounts for a great share of the total CO2 emissions from industry in China. Thus, reducing CO2 emissions from steelworks is urgent for China’s environmental protection and sustainable development. This study aims at identifying factors that influence CO2 emissions from steelworks and proposing measures to reduce CO2 emissions. The life cycle inventory (LCI) of iron and steel products implies the relationship between the CO2 emissions of the steelworks and the input variables of the LCI. The Tornado Chart Tool is utilized to calculate the variation of CO2 emissions caused by the change of each input variables of LCI. Then, mean sensitivity of each input variable is calculated and the ranking criterion developed is used to identify the main factors influencing the integrated steelworks. Subsequently, measures for reducing CO2 emissions are proposed. The results indicate that the very important influencing factors of CO2 emissions in steelworks are the CO2 emission factor of Blast Furnace Gas (BFG), liquid steel unit consumption of continuous casting, continuous casting slab unit consumption of hot rolling and hot metal ratio of steelmaking. Consequently, many efficient measures for reducing CO2 emissions have been proposed, such as removing CO2 contained in BFG, decreasing the hot metal ratio of Basic Oxygen Furnace (BOF), recycling BFG, optimizing the products’ structure, etc.
Authors: Han Seo Ko, Yong Jae Kim, Oh Chae Kwon, Koji Okamoto
Abstract: Velocity and density distributions of a high-speed and initial CO2 jet flow have been analyzed simultaneously by a developed three-dimensional digital speckle tomography and a particle image velocimetry (PIV). Three high-speed cameras have been used for the tomography and the PIV since a shape of a nozzle for the jet flow is asymmetric and the initial flow is fast and unsteady. The speckle movements between no flow and CO2 jet flow have been obtained by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays for density gradients. The three-dimensional density fields for the high-speed CO2 jet flow have been reconstructed from the deflection angles by the real-time tomography method, and the two-dimensional velocity fields have been calculated by the PIV method simultaneously.
Authors: Xian Bi Li, Ru Bing Han, Zhong Hua Tang
Abstract: This paper mainly analyzes the high efficiency characteristic of cross-critical carbon dioxide cycle refrigeration, especially when this refrigeration system works as a heat pump. When this refrigeration system is used as heat recycle system with larger different temperature and high level temperature, the solely superiority and energy saving capability of this system will reveal. However, the development localization of cross-critical CO2 cycle refrigeration system also exists, which includes immature cross-critical CO2 flow and heat exchange theory, and seal problem of compressor, expansion ratio of expansion equipment.
Authors: Jun Jing Guo, Wen Bin Chen
Abstract: This paper forecast alkali capacity demand for energy and CO2 let in China through scene analysis by NICE model .As the major downstream industries of alkali production industry are building materials and paper, pharmaceutical, chemical industry, and a large part of these are glass, paper and chemical industry. So we choose glass, paper, soap, cloth as the base demand of the main relevant factors, using SPSS15.0: the future demand for caustic soda is strong linear relationship of glass and paper; the demand for soda ash is strong linear relationship of glass and soap.The results show that alkali capacity of China will reduce, the demand for energy and CO2 let will be also reduced in 2010.
Authors: Kanji Tsuru, Akihiro Otsu, Michito Maruta, Alireza Valanezhad, Giichiro Kawachi, Akari Takeuchi, Shigeki Matsuya, Ishikawa Kunio
Abstract: The purpose of this study is to investigate whether calcite blocks with high mechanical property could be obtained for a short period from calcium hydroxide (Ca(OH)2) compact using heat-treatment under carbon dioxide (CO2) atmosphere. The Ca(OH)2 disks compacted with different pressure was heated at different temperature ranging from 200°C to 800°C for an hour under CO2 atmosphere. From the X-ray diffractometry, Ca(OH)2 converted into calcite along with the rise of the heating temperature. Small amount of unreacted Ca(OH)2 remained in samples heated at 600°C whereas samples treated at 800°C converted to calcite with very small amount of calcium oxide. The diametral tensile strength (DTS) value increased with the rise of heating temperature up to 600°C then decreased down to 800°C. Meanwhile, the porosity decreased with the rise of heating temperature up to 600°C then slightly increased up to 800°C. From the scanning electron microscope observation, grains grew bigger along with the rise of heating temperature. Intergranular space between grains decreased from 200°C to 600°C. The highest DTS value (14 MPa±1.3) at 600°C could be the result of lesser intergranular space due to sintering.
Authors: Chang Bao Wen, Yong Feng Ju, Wan Lin Li, Wen Zheng Sun, Xin Xu, Yan Shao, Yan Ming Li, Li Min Wen
Abstract: Carbon dioxide (CO2) gas sensor using surface acoustic wave (SAW) device based on Zinc oxide (ZnO) was developed and fabricated in this paper. The center frequency of SAW device is 203.528 MHz. The input and two output interdigital transducers (IDT) apodized by Morlet wavelet function can improve the side lobe rejection compared with uniform IDT. The ZnO film sensitive to CO2 gas was fabricated in measurement acoustic track of SAW device. Experiments results confirm that the CO2 gas sensor using SAW device based on ZnO film has good response characteristics to different concentrations CO2 gas. Furthermore, the CO2 gas sensor using SAW device based on ZnO film has good stability and linearity.
Authors: Soo Young Park, Jin Seog Kim
Abstract: The carbon isotope ratios in foxtail seeds, which grow well anywhere such as a residential street, roadside, empty lot, field etc., were measured by EA/IRMS (Elemental Analyzer/ Isotope Ratio Mass Spectrometer). The samplings were carried out in two ways. One set of foxtail seeds was sampled at 11 different locations to examine the effect of the traffic frequency in Daejeon and its suburbs. The other set was collected in three separate areas to examine the distance effect from the roadside. The d13C values of foxtails were increased at a distance from the center of Daejeon City. According to the results for the other set to examine the distance effect from the roadside, the d13C values of foxtails grown close to the roads were lower than those far away from the road. It means that the roadside foxtails are highly affected by automobile exhaust gases. This effect strongly decreased as the distance from the road increased, because the pollution gases by the vehicles diluted well with the air, even at 5 m from the road. We propose that these results can be used in the monitoring of the hazardous atmospheric pollutants caused by fossil fuel in addition to the monitoring of carbon dioxide.
Authors: Hao Ze Wu, Jun Chang, Zheng Zhao Pan, Xin Cheng
Abstract: Accelerated carbonation is a new technology of materials preparation, which may have potential for the treatment of industrial solid residues and the sequestration of CO2, an important greenhouse gas. In this study, accelerated carbonation was used to recycle steelmaking slag and sequestrate CO2 to manufacture building materials. The experimental results show that the strength of specimens increases along with the increase of carbonation degree. Moisture content, carbonation temperature and curing time have significant effects on the degree of carbonation, and carbonated specimens have larger weight increase and compressive strength increases under the condition of moisture content 12.6%,reaction time 117 min and reaction temperature 361 K. The SEM and XRD analyses indicate that dogtooth like CaCO3 crystals appear on the surface of carbonated aggregate specimens. Strength and soundness test shows that steelmaking slag building materials have higher strength and eligible soundness after accelerated carbonation.
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