Hi
You can "estimate" the losses as follows :
Losses are due to 2 accounts - A : Carryover & B : Evaporation (or vapour pressure related)
A. With a proper demister in place you can have a typical liquid carryover loss of 0.1 USG/mmscf from a column - Use this to estimate carryover losses
B. This would depend on the temperature / pressure of operation and you can estimate this by saturating the gas with TEG and estimating the same at the Contactor. At the Flash drum and Reboiler, the over heads should contain dissolved hydrocarbons, stripping gas (at reboiler, where used), and the moisture that has been picked up at contactor and is released.
For a plant of 150 mmscfd, Contactor operating at approx. 3 kgs/h when operating at 44 deg C and 65 bara.
Hope this helps.
Rgds