Do I need a Chinese Visa on transit?

I am a student from World Maritime University holding a Bangladeshi official passport and a Swedish residence permit card.We have a field study tour in korea in may.

I have a plan to visit my home country from Busan to Dhaka by China eastern airways with a stop over as transit less than 24 hrs at Beijing airport and like wise travel back to Inchon, Korea for onward connecting back to Copenhagen via Korean airlines.
I would appreciate if could confirm whether under this circumstances i require a Chinese visa while transiting through Beijing?
Thanks and best regards