การศึกษาผลของอัตราส่วนสมมูลที่มีต่อปฏิกิริยาเผาไหม้ของแก๊สซิฟิเคชั่นของถ่านหินใต้ดิน

Abstract

Coal is the most common fuel found on the Earth's surface. The deposition of plant matter forms coal through biochemical decomposition under appropriate pressure and heat conditions. The utilization of coal can be classified according to its status, namely the utilization of coal in the form of solid fuel. The use of coal in the form of liquid fuel. The use of coal in the form of gas fuel. This research aims to study the equivalent ratio's effect on converting solid fuel coal into gaseous fuel. Also known as the gasification process. The thermal decomposition behavior of coal was studied using thermogravimetric analytical methods to track the change in the weight or mass of coal. Thermogravimetric analysis (TGA) was performed using a TA Instruments model TGA 8000, Perkin Elmer, USA, under atmospheric pressure. by using nitrogen gas at a flow rate of 40 mL/min. and heating at a constant heating rate of 20 C/min in the temperature range of 50 – 1000 degrees Celsius. The objective of studying the thermal decomposition behavior of coal is to determine the appropriate temperature range. for the design of the experimental conditions From the results of the study, it was found that The maximum decomposition of coal is between 300 and 900 °C. Study of gasification reaction of coal by testing method The conditions of the study were to test the gasification reaction at the equivalence ratio of 0.1, 0.2, 0.3, 0.5, and 0.7, respectively. The experimental set was built of refractory concrete with a 210 mm length and a width of 85. millimeters. The model is 55 millimeters tall and is heated by a burner (Torch) that uses LPG fuel. A gas analyzer will read the gas product obtained from the process. the gas constituents are reduced. When the equivalence ratio is increased, it is found that at 0.1 the equivalence ratio gives the highest gas component. This study uses a mathematical calculation method using a 3D hemisphere reactor model using ANSYS Fluent Ver.2019 R3 software. The size of the model is 90 mm wide, 680 mm long, and 132 mm high. The size of the element sizing was set to 1.2 mm. The turbulent flow k-ε model was used. For the Finite – Rate / Eddy – Dissipation chemical correlation was analyzed together with the chemical sequestration (Ultimate Analysis) and the estimated composition (Proximate Analysis) of coal fuel by using the Coal Calculator model. of the two-step reaction mechanism. The semi-implicit method for the pressure-linked second-order upwind scheme was chosen to calculate the difference in the resultant momentum equation. (Momentum equation) and continuity equation (The continuity equation) including energy equation (Energy equation) to be less than 1x10-4. From the study results, it was found that the temperature inside the model would increase with increasing equivalence ratio While the composition of the product gas is The carbon dioxide (CO2) and carbon monoxide (CO) gas components tend to decrease with increasing equivalence ratios. In the comparison of the results of the experimental product gas composition and the results obtained from mathematical calculations using ANSYS Fluent software, it was found that the trends of carbon dioxide (CO2) and carbon monoxide (CO) gas composition were there is the similar trend by the composition of carbon monoxide gas It increases in the range of the equivalence ratio between 0.2 - 0.3 and decreases as the equivalence ratio increases. while the composition of carbon dioxide increases in the range of the equivalence ratio between 0.3 - 0.5 and decreases as the equivalence ratio increases as well.