Dissertation > Excellent graduate degree dissertation topics show

Study on the Mechanism of Calcium-based Desulfurization and Decomposition of Sulfur Products in Different Atmosphere

Author: WangXiaoFeng
Tutor: QiuJianRong；LiuHao
School: Huazhong University of Science and Technology
Course: Thermal Power Engineering
Keywords: Oxy-fuel combustion direct sulfation SUC model decomposition of CaSO4 in high temperature sintering of CaO
CLC: X773
Type: Master's thesis
Year: 2011
Downloads: 23
Quote: 1
Read: Download Dissertation

Abstract


Coal is the most important resource and 70% electric power is produced by thermal power plants in China. Various pollutants are caused by coal combustion, including SO2, NOx, CO2 and heavy metal pollutants. Recently, green house effect is paid more and more attention. Oxy-fuel combustion is a new type of combustion which is developed to reduce the emission of CO2. Because of flue gas recirculation the reaction between limestone and SO2 has different features in oxy-fuel combustion to conventional combustion. In this work the methods of experiment and simulation were used to study the features of calcium based sulfation.The method of thermodynamics analysis was used to discuss the characters of calcium based sulfation. Decomposition of CaCO3 in high temperature, the reaction between CaO and SO2, direct sulfation and decomposition of CaSO4 in high temperature were contained. A relation between SO2 partial pressure and O2 partial pressure was considered as one parameter when discussed indirect sulfation. SO2 and O2 equilibrium pressure were calculated by the method of thermodynamics analysis. It is the foundation for model calculation below.The reaction between limestone and SO2 was studied in TGA and the model of direct sulfation was improved. Based on SUC model, gas diffusion was considered as the way of matter diffusion through product layer. Meanwhile, a new method of calculating chemical reaction rate constant and reaction order of SO2 was proposed and the value is 0.745. When calculating the gas diffusion coefficient of product layer, average porosity and average pore radius were considered remaining unchanged during reaction and the method of calculating gas diffusion coefficient was improved sequentially.The model of CaSO4 decomposition in high temperature was also proposed in this work. The effects of SO2 partial and O2 partial were considered and the sintering of product layer was calculated based on the sintering of CaO from limestone calcination. Meanwhile, a new method of calculating calcination rate coefficient from the data obtained in inert atmosphere and temperature programming was proposed. The change of SO2 partial pressure, O2 partial pressure, average porosity and average pore radius of product layer on unreacted core were discussed based on the model. The features of calcination in constant temperature were also discussed.

Related Dissertations

  1. Numberical Simulation of Pulverized Coal Oxy-fuel Combustion Process,TK16
  2. Experimental, Study and Numerical Simulation for Oxy-Fuel Combustion Characteristic of Pulverized Coal-Fired Boiler,TK229.63
  3. Pilot Plant Experiment and Simulation Research on NO_x in Oxy-fuel Combustion Technology,X701
  4. Experimental Study of Fuel N Conversion in Oxy-Coal Combustion,TK16
  5. Research on Vaporization Behavior of Selenium in Oxy-fuel Combustion Process,TK16
  6. The Study on Lignite Upgrading and Its Effect on Combustion Characteristics,TQ534
  7. Physical Fields’ Characteristic Study & Structural Optimization of a SCR Denitrification Reactor,X773
  8. Study on the Variation of Mercury Existing States in Fly Ash during Thermal Treatment Process,X773
  9. Synthesis of Functional Ionic Liquids and Characteristics of CO2 Capture,X773
  10. Experimental Study of Mercury Removal with Wet Flue Gas Desulfurization System,X773
  11. The Study on Properties of Desulfurization and Denitrification by Mn/Al Catalysts,X773
  12. Experimental Research of Chemically Modified Silicate for Mercury Removal from Flue Gas,X773
  13. Optimizaiton of SCR Flue Gas Denox Sysytem and Study on Fly Ash Particle Motion in Coal-Fired Plant,X773
  14. Study on the Adsorption of Different Mercury Forms from Flue Gas by Coal Char,X773
  15. Agglomeration System Design of 300MW Coal-fired Power Plant and Numerical Simmulation Study,X773
  16. The Research on Release Characteristics of Nitrogen Oxides from Blended Coal on the O2/CO2 Atmosphere,X773
  17. Luan River pulverized coal-fired power plant ash removal system design and system optimization selection,X773
  18. Research on Compressive Strength and Reinforcement Mechanism of the Fly Ash Blended with Solidified Agent,X773
  19. Research on Surface Modification of Fly Ash and Its Application in Prepartion of Blended Cement,X773
  20. Preparation of de-NOx Catalysts Containing V-W and Their Application in Selective Catalytic Reduction of NO,X773

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > Power of industrial waste treatment and comprehensive utilization > Electric Power Industry
© 2012 www.DissertationTopic.Net  Mobile