The Thermal Decomposition of Corn Starch

• Main Authors: LIN,YU-FANG, 林聿方
• Other Authors: LIAW,HORNG-JANG
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/zxv97q

碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程系碩士班 === 105 === Dust explosions are formed by flammable gas which decompose by dust after heated to certain extent, then uniformly mixed with air and ignited by a source with sufficient energy. Which means the combustion of dust occurs by its flammable gas, not dust itself. Besides flammability limits of flammable gases, heat energy is also an important factor needs to explore in dust explosion. When temperature greater than a certain extent can cause a lot of dust decomposition during the heat treatment process of dust, which means the dust under that high temperature condition will lead to a certain degree of fire and explosion risk. Therefore, it is necessary to investigate the thermal decomposition of dust for dust explosion. This study is to investigate the changes of mass and energy change of corn starch in the process of giving heat treatment. Choose isothermal thermogravimetry and dynamic thermogravimetry method of Thermogravimetric analysis (TGA) and Simultaneous Thermal Analysis (DSC/TGA) to observe the relationship between mass loss, decomposition rate and temperature, and the change of heat and decomposition. Also use the Fourier Transform Infrared Spectroscopy (FTIR) to analysis decomposition products of corn starch then use ATR, the accessory of FTIR, to analysis the difference between corn starch itself and after being heated. Combine with these analyses to investigate the difference between the cracking reaction and the essential composition of the corn starch during heating process. Finally, using the Arrhenius Equation to calculate the activation energy of decomposition of corn starch. The results shows that during thermal process corn starch will have three stages’ mass loss, and the main stage is about 270°C~320°C which results its mass about 25% remains only. Also, it is found that corn starch will decompose large number of carbon dioxide, water and C=O stretching vibration released during the main stage. The result can be used in the fire and explosion risk assessment and hazard control for the circumstance of existence corn dust.