The properties and compositions of the bio-oil from fast pyrolysis of two typical biomasses: apricot stone and corncob in a free-fall reactor were studied through column chromatogaphic separation.

In the process of free falling of particle stream,the ambient air may be drawn into the particle stream to form a particle plume.

The experiment of “free fall” in experiment textbook of Department of Physics Loughborough University of Technology as a good example is introuduced.

The axial and radial distributions of the local particle velocities at different radial positions on various axial levels along the downer-column were measured by using a PV-4A fiber-optic particle velocity probe in a half-column downer of 2 m high and  30 mm I.

The key problem of coking seriously restricts the stable and continuous operation in thermal plasma downer reactor for the coal cracking process to produce acetylene production.

The latest progresses of residuum catalytic cracking reaction technology were introduced,such as millisecond catalytic cracking process, the technology of catalytic cracking with down flow reactor , two staged riser catalytic cracking process and the family technology of producing lower carbon olefin by residuum catalytic cracking.