Transit via beijing from Montreal

Hi! I am going on a 3 weeks trip. I booked a round trip plane ticket from montreal (yul-pek-yul). But i do not intend to stay in beijing. This would be my itinerary:
1. Montreal to beijing and when i arrive in beijing, i take the plane on the same day for hongkong. After 3-4 days in hongkong, i will be going to thailand
2. For my flight back, i will do thailand-beijing-montreal, with the intention to stay 2 days in beijing...

Do i qualify for the 72hours visa free?