EXTRA CREDIT
Molin Cheng After reading these two articles we can see each of them use a different way to improve ethylene yield. The two have the same goal, but also has a conflict theory and each of them have its advantages and disadvantages.
First, let’s talk about the article “Oxidative Pyrolysis of Ethane”, which assumes that the effects of the oxygen addition can be beneficial to industrial crack in three manners: decreased residence time or increased throughput, higher severity, or reduced tubeskin temperature and longer coil lifetime. After the experiment, the author gets with that the addition of oxygen increases the ethane conversion. The ethylene yields decrease slightly at the feed oxygen compositions higher than 5mol%, which is the result of a slight decrease in ethylene selectivity and most of the oxygen is converted to CO. Then, a computer modeling simulations showed that the oxygen addition has a large impact on the heat effect of the cracking reaction, that means the residence time can be lowered, the severity of ethane cracking can be further increased and the tubeskin temperatures can be lowered. In brief, the addition of oxygen can increased the ethane conversion and with the heat effect of the cracking reaction we can extended operation cycle time and coil lifetime, however the ethylene yields decrease after the oxygen compositions higher than 5mol% and will generate a lot of CO. Then, we talk about another article “High Selectivities To Ethylene By Partial Oxidation Of Ethane”. The author made an experiment to show that with the combination of Pt-Sn and amounts of H2, we can get a very high selectivity to the ethylene, more efficient energy use and less pollution. But it still has some problems about the reaction conditions. Because H2/O2 mixtures are flammable or explosive over a wide range of compositions, it make the experiment very dangerous, and we must have new technologies for chemical synthesis by suitable design of