Here is a recent publication from our group on this subject.
The chemical vapor deposition of carbon, such as coke and diamond,
is a significant technological problem. From steam
cracking of hydrocarbons to produce ethylene from abundant resources
such as ethane and naphtha to carbon deposits in internal combustion
engines, the development of a better understanding of the underlying
mechanisms of coke formation is essential for the implementation
of intelligent operating strategies and to develop additives to prevent coke
formation in the first place.
In the Chemical Reaction Engineering Laboratory, coke formation process is being studied directly using a gravimetric micro-balance. In this arrangement, a well defined surface, such as a flat sheet of metal or quartz, is suspended in a temperature controlled furnace. Gases bearing hydrocarbons are then passed over this surface, and the weight change of the suspended surface is then recorded in real time using a computer. Coke formation rate is then determined from the slopes of the weight histories. A picture of the experimental system being used is shown below.
Reference:
Tran, T., and Senkan, S.M., "Coke formation in the pyrolysis and oxidative pyrolysis of Methane and Methyl Chloride," Ind. Eng. Chem. Research, 33, pp. 32-40, 1994.