Ethylene Oxide Purification

[hvc]

In first thank you for your time, i've some problems with the implementation in HYSYS program (in the institute where i'm doing my licence degree) about a separation process to produce Ethylene Oxide 99.5% of purity, from gaseous reactor effluent produced by Shell Oil reaction process.
The desired Ethylene Oxide product stream should have, at least, the conditions presented in the next table.

Stream Feed Product
temp(ºC) 250 46.32
pressure(bar) 16.6 3.5
Ethylene Oxide 366.60 362.04
Acetaldehyde 0.47 0.10
water 321.36 0.60
formaldehyde 1.15 <0.001
argon 175.18 0
nitrogen 60.21 0
methane 5 974.7 trace
ethylene 3 074.4 <0.001
CO2 894.47 <0.001
oxygen 476.82 0
ethane 262.19 0.001

thanks for your help,
best regards

Hélio Carvalho