【Gas Separation Unit】Technology for separating non-condensable gases from C3 and C4
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The last edit to this post was made by Xiao Gong 1985 on 2016-6-11 at 07:49. The overhead gas from the degasifier tower needs to have non-condensable gases such as C2 separated from it; currently, the highest proportion of these non-condensable gases is C3, accounting for up to 60%, and this gas is sent to the catalytic pressure compressor before being recycled； Regarding the vapor-phase deethanizer, new methods for separating C2 and C3 compounds are being sought; CNOOC would like to actively participate in the discussions. Thank you!
I don’t understand what you mean; the feed to the deethanizer, C2, is already very low, so it’s normal for there to be a lot of C3 at the top of the tower! The amount of C2 and C3 extracted from the top of the deethanizer is not large either; the extracted C2 goes to catalytic reprocessing, while C3 enters the dry gas stream in the absorption and stabilization section, thereby achieving the separation of the two compounds! There is no need to set up separate means for C2 and C3 anymore!
C5 or C4 can be added at the tower top for washing, which will result in much less C3 at the tower top.
For the C2/C3 components in the non-condensable gas, it is recommended to use a fan-type high-efficiency gas-liquid demisting and separation element to further separate and recover the C2 dry gas component from the C3 liquefiable gas component, which is relatively easier to liquefy.
Typically, the separation efficiency achieves a 4N level of separation for droplets of 8 microns or larger in size, meaning 99.99% removal of such droplets. It can fully meet the requirements for industrial separation.