Not all Technology Modules in the game can be received for free.
The thing is that you may receive only basic Technology Modules for entering the game every day. Once you research all the basic Technologies, you will start receiving 7% bonus to your Uranium and Titanium production rates.
You may check whether you are already receiving that bonus on the right side of the Technologies window.
Once the bonus unlocks, it will mean that you have only special Technologies left to research. These Technologies unlock special Xenos units. Modules for such Technologies can be purchased for Black Crystals, at the Black Market, or through the Technologies window itself.
The Black Crystals is extremely rare and valuable resource, so the only way to earn them is to compete in Tournaments.