How does it work if I want to bring more than 100 ml liquid with me while traveling, and if this is the onliest thing which is not carry-on baggage ? Can I collect it somewhere after the flight, since they won't throw it on the luggage belt ?

what kind of "liquid"

You have to put in your checked in luggage.

This link pretty well spells it out:

http://www.singapore.embassy.gov.au/sing/LIQUIDS.html

You have to put in your checked in luggage.

But what if I don't have any other checked in luggage, only carry-on luggage ?

What kind of liquid?

Without carry on more than likely out of luck.

They will take it away and throw it in the bin.