Optimum temperature profiles during the pyrolysis of ethane exist because the yield goes up with increasing temperature, but consequently, the reactor must be shut down and cleaned out with increasing frequency because the carbon formed deposits along the reactor wall causing high pressure drop. The combined effect causes the yearly production of ethylene to go through an optimum. To find this optimum, a computer program was developed with the ability of handling 25 simultaneous reactions involving up to 25 components. It calculates the carbon deposition profile and the changing pressure profiles, as a function of a predetermined reaction gas temperature profile. The reactor will remain in production until the inlet pressure exceeds 8 atm. The average yearly production rate is calculated, assessing a reactor shut down penalty of 24 and 48 hr required for the cleaning of the clogged pyrolysis tubes. The optimum exit temperature for the 24-hr penalty was 1127°K with a corresponding 59% one pass ethane conversion. The 48-hr penalty lowers the optimum exit temperature to 1124°K and a 50.5% ethane conversion. The practice of increasing pressure to compensate for carbon buildup results in accelerated carbon deposition and is detrimental to the overall production scheme.