(121a) Golf Meets a Steam Cracking Coil: Dimpled Reactor Technology for the Production of Light Olefins

Heat transfer limitations from a cracking coil to the process gas can have detrimental effects on process economics as they imply an increase in tube metal temperatures and reduces the time in between two decoking procedures. To enhance heat transfer, wall modifications such as fins or ribs can be introduced to increase the heat exchanging surface or to promote turbulence. These rudimentary wall modifications however introduce an excessive pressure drop which is detrimental to the light olefin selectivity. With the use of supercomputing and Computational Fluid Dynamics, it was shown that spherical dimples on the reactor inner wall can significantly enhance heat transfer at a very low pressure drop penalty. Experimental data obtained at the Von Karman Institute further confirm the potential of using dimpled reactor tubes. Implementation of such a dimpled cracking coil, leads to a low pressure drop penalty and the improved radial mixing leads to a more uniform temperature distribution, favoring the production of propene. Furthermore, the reduction of the wall temperature can increase run length by up to 40%.