Tuesday, May 5, 2020
Effects of CO2 and H2O Mixture-Free-Samples-Myassignmenthelp.com
Quetion: Discuss about the Clean coal technology: Effects of CO2 and H2O mixture on intensified gasification of residual carbon in partially gasified char. Answer: Introduction Coal is one of the major fuels which have been used for long in different sectors. Coal is a product of carbon and its gasification is divided into two different steps of coal pyrolyzation and char gasification (Zhou et al. 2006, p.13). Gasification process involves water evaporation and therefore carbon dioxide and water vapor has great effects in gasification of carbon residue in order to produce clean energy. The clean coal technology is able to involve gasification of coal with syugas. Carbon is able to react with carbon dioxide and water to produce different products. When coal is heated, it produced char and after gasification, char residue is produced. Char is a combination of carbon and ash (Malekshahian Hill 2011, p.22). In addition, coal is able to occur at different stages and this is able to affect its gasification process. Some of the key parameters which are able to change during gasification process include the temperature, carbon particles, ash content and char. Thes e factors are able to depend on the amount of carbon dioxide and water allowed during the gasification process of the coal. During the gasification, coal is able to pass through the fixed bed, entrance bed and lastly the fluid bed. CO is reacted with hydrogen gas in presence of oxygen in order to produce CO2 and water. The produced char, which is coal, is able to react with carbon dioxide to produce CO and with water to produce CO and hydrogen gas (Jeong, Park, Hwang 2014, p.31). Therefore the mixture of carbon dioxide and water are able to affect the gasification process and residue of carbon. In this project, different materials were investigated. Chinese coal, Shenmu and Tejing were used in the analysis of the effect of water and carbon dioxide in the gasification process. The composition of the two coals will be made in this report. In addition, effects of carbon dioxide and water during the gasification process will be key in this project (Hou et al. 2014, p.45). Carbon is usu ally in residue form. Changing the temperature is able to affect the results of the ash produced in different cases. This report and project will analyze the different products of ash which are produced in the different coal types. Aim To determine the effects of carbon dioxide and water on the residue of carbon in the gasification process through analysis of the different changes of parameters. Objectives The project will also analyze the different factors change when the CO2and water are used in the gasification process. To investigate the effect of increased temperature on the gasification process of coal To investigate the amount of ash produced when different amount of carbon dioxide and water are used To analyze the ash composition in the two different types of coals used Scope This project will focus on the different effects which are achieved during the gasification process of coal. Increasing temperature during the process has some key effects. Water and carbon dioxide are able to play important roles in this process and increase temperature affects their functionality. In addition, this experiment will be able to investigate the different products which are produced during the process. Changing the conditions and key parameters will as well affect the amount of products which are produced. These include the ash and char (Deng, Luo, Zhang Wang 2012). Gasification process is highly affected by the increase of temperatures and this project will investigate the way different products are able to change when the temperature is changed within the process. This project will highly investigate the effect of heat increase on the production of the different products. The heat change is able to affect the reactivity rate of the coal and present reactants (Bai et al. 2014). Materials: The major materials which will be used in this project include the typical Chinese coal: Shenmu and Tejing, will be employed in this work. The proximate and ultimate analyses and ash composition of these two coals are as follows: Mad Ad Vdaf Fcad Industrial Analyze (%) of Shenmu coal: 6.62 5.08 33.04 59.35 Industrial Analyze (%) of Tejing coal 5.41 13.63 43.48 46.18 Description Ash produced is able to compose of different compositions of materials. The results depend on the different coal type which is analyzed in each status (Lahijani, Zzinal, Mohamed Mohammadi 2013). Shenmu Coal and Tejing coal are able to produce different ashes with different characteristics and compositions of the products. Addition amount of water in the process and CO2 is able to affect the ash composition produced in the process. The analysis will be able to find the different effects which are achieved when the carbon dioxide and water are exposed in different temperatures during the gasification process. Ash is one of the key products which are produced during the gasification process of coal. This experiment will be able to analyze the ash composition in coal. To achieve the result in this project, gas flow controller will be utilized. Gas cylinders will be used to create the high temperature furnace (Gao, Vejahati, Katalambula Gupta 2010). In addition, reaction tubes will be used to ensure that the gasification of coal is controlled and not highly affected by external conditions. Gas anatuper will be as well be used in the process. Factors are investigated Temperature (?): 800, 850, 900, 950, 1000, 1050, 1100, 1150; Particle size (um): 100~250, 250~500, 500~600, 600~1000, 1000~1500; Ash content (%): 10, 30, 50, 70, 90; Char: Graphite, Shenmu, Tejing; Gas flow rate (NL/h): 1; Gasification atmosphere (atm): Pure O2; 0.2H2O: 0.2O2+0.6N2, 0.4O2+0.4N2, 0.5O2+0.3N2, 0.6O2+0.2N2, 0.8O2+0N2; 0.4H2O: 0.2O2+0.4N2, 0.4O2+0.2N2, 0.5O2+0.1N2, 0.6O2+0N2; 0.5H2O: 0.2O2+0.3N2, 0.4O2+0.1N2, 0.5O2+0N2; 0.6H2O: 0.2O2+0.2N2, 0.4O2+0N2; 0.8H2O: 0.2O2+0N2; Pure H2O. Proposed work plan and methodology Work plan Activity Timeline 1 Proposal writing 2 weeks 2 Training 3 weeks 3 Experiments 5 weeks with 1.5days per week Methodology A type R thermocouple will be inserted through the gas ducting tube with the tip located above the sample. Then the gas ducting tube will be assembled into the sheath and fixed with screws. The samples will be preheated to the target temperature in pure Argon atmosphere, and then a gas mixture of defined composition will be blown into the gas ducting tube. The gas flow rate and composition are controlled by mass flow controllers. Pure Argon will be used for annealing, while feed gas with different composition will be used for gasification experiments. The off-gas composition will be monitored by a gas analyzer. The process will be repeated at temperature changes to different temperatures such as 800, 850, 900, 950, 1000, 1050, 1100 and 1150o Conclusion Different parameters are able to affect the gasification process. Carbon dioxide and water are some of the critical parameters which are essentials in the gasification of residual carbon in partially gasified char. These changes on temperature are able to change the products which are achieved. Ash is produced and at different situations it leads to different composition. In addition, coal is the main carbon product which will be utilized in this project. Two main types of coal will be utilized and their differences in the product produced will be analyzed. The result will be able to show how changes in the two factors are able to affect the gasification process of carbon. In addition, the char compositions are able to have different composition when the amount of intensified water and carbon dioxide are changed. References Bai, Y.H., Wang, Y.L., Zhu, S.H., Li, F., Xie, K.C., (2014). Structural features and gasification reactivity of coal chars formed in Arand CO2atmospheres at elevated pressures. Energy 74,464470. Deng, J., Luo, Y.H., Zhang, Y.L., Wang, Y., (2012). Investigation into synergy in co-gasification of coal and char of biomass by thermo gravimetric analysis. J. Fuel Chem. Technol. 40 (8),943951. Gao, C., Vejahati, F., Katalambula, H., Gupta, R., (2010).Co-gasification of biomass with coal and oil sand coke in a drop tube furnace. Energy Fuels 24 (1), 232240. Hou, W., Zhou, Z.J., Chen, X.L., Dai, Z.H., Yu, G.S., (2014). Study onCO2gasification reactivity and physical characteristic of biomass, petroleum coke and coal chars. Bioresour. Technol.159, 143149. Jeong, H.J., Park, S.S., Hwang, J., (2014). Co-gasification of coalbiomass blended char with CO2 at temperatures of 9001100?C. Fuel 116, 465470. Lahijani, P., Zzinal, Z.A., Mohamed, A.R., Mohammadi, M., (2013).CO2 gasification reactivity of biomass char: catalytic influence of alkaline earth and transition metal salts. Bioresour. Technol. 144, 288295. Malekshahian, M., Hill, J.M., (2011). Effect of pyrolysis and CO2 gasification pressure on the surface area and pore size distribution of petroleum coke. Energy Fuels 25 (11),52505256. Zhou, Z.J., Fan, X.L., Zhang, W., Wang, F.C., Yu, Z.H., (2006). Char gasification kinetics using non-isothermal TGA. J. Chin. Coal Soc. 31 (2), 219222.
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