The present disclosure relates generally to novel biomass pyrolysis processes and systems that decrease entrainment of char and other contaminants with the pyrolysis vapors. In certain embodiments, the present disclosure provides methods and systems to prevent entrainment of particles of char and heat carrier with pyrolysis vapors leaving a reactor, while allowing rapid upgrading of the vapors by catalyst(s) that are held in a an upgrading reactor and protected from contact with the char.