hads,
240V/50Hz... is that 120V on 2 legs? I am not that familiar with that power.
Check out the data sheet for the opto-triac drivers. Intelligent Power and Sensing Technologies | onsemi it has some 240V examples. Basically the same setup with some different resistor values between the opto-coupler and triac. The zero-cross can stay the same, just ensure you adjust the resistor value for the rating of the H11AA1 maybe 50k?
Remember, if you want to switch high current loads with this, your PCB needs to have large traces and a heavy copper layer to handle the current, even though the triac may be rated for 12A make sure the interconnects are as well!