The application of carbon dioxide (CO2) absorbent particles to capture greenhouse gas emission in power generating plant is one of the currently capable technologies that could improve the power plant efficiency. Based on the carbonation and calcinations reaction, it was found out that the reaction of calcium oxide (CaO) and CO2 is a promising method to eliminate CO2 from the gas produced from the combustion of the fuel. Granulation process is one of applicable method that can be used to produce the sorbent particle. According to Lister and Ennis (2004), granulation is a process of transforming fine powders to agglomerated granules with controlled physical properties. In the experiment, drum granulator will be used as the main apparatus to conduct the granulation process.
This thesis project is concentrate on developing the calcium-based particles sorbent particles that has high mechanical strength and high CO2 capture capacity. This experiment was also investigate the factors that affect the product of the granulation process such as critical drum speed, binder concentration, spray flux and selection of binder and coating materials. The core materials and binder solution were mixed together and revolved in the drum to form granules. After the core material is produced, it is dried and heated up to develop particle toughness. A core material is then coated with a shell to form a core-in-shell material. The final product of granulation process was tested in order to determine its physical and chemical properties. The attrition and abrasion resistance of the products were tested using the Vankel Rotary Attrition Tester. Finally, Thermogravimetric analyzer (TGA) was used to test the capacity of CO2 adsorption and desorption of the particles.
Calcium carbonate (CaCO3) and Dolomite (CaCO3.3MgCO3) were chosen as proposed core materials for this project. Polyvinyl Alcohol (PVOH) and Polyethylene Glycol (PEG) were used as binder during the granulation process. Cement and fireclay were chosen as shell materials for the coating process. This project had determined the best combinations of all the core, binder and shell materials that could produce the particle that has lowest attrition rate, high compressive strength, high CO2 absorption capability and inexpensive. From work done in this project it was found that best combination to produce CO2 capture sorbents is by using dolomite with 3% concentration of PVOH solution and coated with fireclay.