MTO: A Light Approach To Plastics Via Non-Petroleum Route

Plastics have become a vital asset for humanity where its consumption is dominated by polyethylene, polypropylene, polyester, and PVC with light olefins (i.e. propylene and ethylene) emerging as the backbone in the plastics industry.  Due to its recyclability and variety of applications, ethylene has become one of the most widely used organic compounds.  Propylene is also used to manufacture polypropylene which is responsible for almost two-thirds of the global propylene consumption.  Globally, the annual production of ethylene and propylene is 134 million metric tons and 94 million metric tons respectively.  In the late 1970s, there was an oil crisis that prompted petrochemical industries to find nonoil resources to produce basic petrochemicals.  After much deliberation and research Exxon Mobil discovered a non-petroleum route to convert methanol to olefins (MTO) in the presence of ZSM-5 zeolite-based catalyst in 1977.  Next, Union Carbide combined MTO with a SAPO-34 catalyst which is highly selective towards light olefins.  UOP Honeywell and Dalian Institute of Chemical Physics (DICP) researched more to improve upon the MTO process.  The first MTO plant in China was commercialized by UOP in 2010.  In this project, SAPO-34 catalyst was chosen to maximize the selectivity to 80% for light olefins.  The reactor used will be a circulating fluidized bed catalytic reactor coupled with a catalyst regeneration chamber with pure methanol as the raw material.  Catalyst regeneration and heat integration are just some of the ways this MTO plant will show its economic success.  The considered methanol price is less than the average market price because of 25-years long plant contract.  With abundant reserves of coal and methanol’s reduced price, China was chosen for the location to build the plant.  Utilizing the latest technology alongside a wide-open Chinese market, this MTO process plant will be a staple in plastics for future generations.