if you take 1.5 liters of alcoholic beverages (alcohol measure above 12 degrees), it is duty free. If the amount you take exceeds that limitation, you need to pay duty. As for the maximum amount of alcohol, my suggestion is do not take too much, take a resonable amount in case of misundestanding at Customs. And i am sure that it is impossible to take as much as you want. Remember that alcohol can only be put in checked baggages.