(48b) DTP R Process: On-purpose Propylene Production Technology

Propylene has been a major source material in the petrochemical industries, and further growth in their global demand can be expected. Propylene is mainly produced as a co-product from steam cracker utilizing naphtha as feedstock. Recently, the shift to gas based feedstock in petrochemicals is proceeding in the area in which it is possible to obtain gas based feedstock inexpensively. The shift of steam cracker feedstock from oil based “naphtha” to gas based “Ethane” causes reduction of propylene production because propylene yield from ethane cracker is much lower than that from naphtha cracker. As a result, propylene shortage is predicted. With these backgrounds, attention has become focused on the propylene production processes intended for “on-purpose” propylene production, and their commercialization is eagerly awaited.

JGC Corporation and Mitsubishi Chemical Corporation have jointly developed the DTP ^R process in which propylene with high yield is produced by using not only DME or methanol which is produced from low cost feedstock in comparison with oil such as methane and coal, but also low value olefins such as various C4 olefins from liquid crackers or lower olefins from FCC. The basic process design is derived from the data gathered at a demonstration plant constructed at Mitsubishi Chemical’s Mizushima Plant. Continuous operation had been successfully conducted and the accumulated operation time was over 10,000 hr. The DTP ^R process is ready for commercialization.

This process features modified ZSM-5 zeolite catalyst which ensures high propylene selectivity and stable performance. For the DTP ^R reaction, along with MTO (Methanol to Olefins) reaction, the selectivity to propylene increases with increasing reaction temperature. Nevertheless, the reaction temperature is generally controlled lower than the optimum temperature because zeolite deactivates through the exposure to high temperature steam. The DTP ^R process adopts relatively higher reaction temperature compared with the competing technologies to maximize propylene selectivity. We continue to improve hydrothermal stability of the catalyst for extending the catalyst life and have developed the advanced catalyst. By applying higher reaction temperature, C4-C6 olefins from liquid crackers or FCC can be used as feedstock with oxygenates.

In this presentation, not only features of DTP catalyst but also overview of DTP process and economics of this process will be provided.