As we enter the last hump day of the Fall 2014 regular season, things are closing out quickly. It is especially true for our senior design project; the due day for the final design projects is 4pm on Monday, Dec. 8th. There’s going to be a lot of cramming happening in the next 5 days, and a lot of all-nighters going to be pulled. At the final stages of this project, there’s a few things to need to do. One of the biggest things is CO2 removal.
First of all, we need to come up with goals. We need to implement a CO2 removal system into our EO production plant. There’s 3 options (really there’s 2). The first option is using a magical separation column in Aspen which magically removes CO2 from the system and recycles ethylene feed. It’ll allow us to close the recycle loop easily and simultaneously have the rest of the flowsheet converge. However, This option is technically crossed out because it’s not a real thing we can in real life (Come on keep it real guys).
This leads to option 2. Option 2 involves actually implementing a CO2 absorption column; usually an MEA column is used for this purpose. However, we’ve tried and realized that ethylene and CO2 behave similarly in separation and it’s difficult to separate one from another. We’re currently looking into other possibilities such as a different solvents or different methods of separation.
The last option is to add a splitter in the recycle stream to reduce the amount of CO2 in the stream returning to the feed. The way some of the ethylene is recycled, but some of ethylene is wasted. The fuel gas containing CO2 and ethylene can be burnt and sold for money. A price tag is going to be put on that.
After evaluating our options, we’ve decided that option 3 is our base case. It’s certainly not the most ideal case, but it can be our last resort at the moment. The reach goal would be to implement a CO2 removal system that removes CO2 and returns clean ethylene to the feed stream. Right now we’re looking into solutions, and let’s make things work.