No. 393: A new naphtha cracking technology for lower deterioration of the catalytic activity and higher process yield (December 28, 2011)

A research team led by Prof. TakashiTatsumi of Tokyo Institute of Technology developed a new petrochemical process that slows down the deterioration of the catalytic activity and enables to get more useful components by miniaturizing the zeolite catalyst used for naphtha cracking to a nanometer-scale. The research members examined 27 kinds of zeolite catalysts and narrowed down 2 kinds that have the optimal structure. They decreased the particle diameter of the catalyst to 100-200 nanometers that is about one tenth of the standard diameter and improved the problem with the separation of carbon on the surface of the catalyst, and successfully decreased the separation of carbon by controlling the reaction temperature with added moisture vapor.

The new process has to achieve a longer than 48 hour continuous catalyst reaction and an about 8 hour cycle of catalytic generation for practical application. The research members are confident that further research will enable the process to clear the two targets. Although the propylene yield normally decreases with time, it can be maintained with the help of a nanoscale zeolite catalyst. In addition, the new process enabled the thermal cracking ratio of producing useful components as petrochemical materials, such as ethylene and propylene, to improve about 10% to 67%. Thermal naphtha cracking consumes lots of energy because it needs a high temperature of higher than 800 degrees centigrade without catalyst, but the required temperature can be reduced to 650 degrees centigrade by using a catalyst. The research team is trying to put the new process into practical application as soon as possible.