The purpose of this study was to gain insight into the role of mass transfer in the pyrolysis of bitumen. The yield of cracked products and coke from pyrolysis of bitumen fractions was measured as a function of pressure. The mass of residual liquid and coke at any time was monitored by TGA. The TGA results over a range of pressures was used to distinguish evaporation from reaction and investigate the role of mass transfer in determining the ultimate yield of coke. For convenience, we define coke as the residue remaining in the sample pan after the sample was heated to 600℃. In all cases the incremental change in weight was insignificant at temperatures above 600℃.
