| With the rapidly increasing demand for fuel throughout the world, the need to explore alternative energy resources is vital. Natural gas is extraordinarily abundant throughout the world, unquestionably surpassing petroleum reserves. However, much of it is located in remote or inaccessible areas. To tap this potentially lucrative source, a new, efficient and economic process to convert natural gas to liquid hydrocarbons is proposed.; There are two central components to this process, a methane pyrolysis reactor and a liquid catalysis reactor. Natural gas mixed with a hydrogen recycle stream enters the first reactor to reduce the amount of coke produced from cracking methane/ethane. Depending on the composition of the gas, the temperature will vary between 1200 K and 1800 K. The separated hydrocarbons from the furnace reactor are then sent through a catalytic reactor, forming liquid hydrocarbons with an average C6 molecular weight. The methane cracking or pyrolysis reactor is the focus of this research.; A kinetic simulation model was developed to predict product composition for methane pyrolysis at various feeds, residence times, temperatures and pressures. The residence time is higher for lower gas temperatures and is lower for ethane vs. methane at the same temperature. The effect of ethane on methane conversion, acetylene formation and coking was examined. At high temperatures above 1800 K, ethane quickly decomposes resulting in higher coke formation. Diluting methane with hydrogen was found to significantly reduce coke formation at all residence times and especially at high temperatures. When operating at higher pressures, higher methane conversions and greater C2 hydrocarbon yields are realized.; In designing this process, a kinetic model is important as is the determination of the proper energy and heat transfer requirements. Experiments are conducted using helium gas to estimate heat transfer coefficients at furnace temperature ranges of 673--1273 K and at flow rates of 5--35 L/min. Our experimental results at higher flow rates were almost equivalent to the heat transfer coefficients found using standard models such as the Hausen equation. |
