Characteristics of Slurry phase Direct DME synthesis technology

[1]Catalyst system for DME synthesis reaction

・3 function (Methanol synthesis +Dehydration +Shift) catalyst system realizes DME synthesis reaction with high equilibrium conversion from syngas of H₂/CO=1.

 This ratio is adequate for carbon rich resources such as biomass and coal.

・Equilibrium conversion of DME synthesis is so high that DME can produced at lower pressure in comparison with methanol synthesis.

・Proprietary catalyst with high conversion and selectivity is demonstrated to have sufficient lifetime in slurry phase reactor.

[2]Slurry phase reactor

・DME synthesis reaction is so highly exothermic that control of temperature distribution in the reactor is important.

・Figure 3 shows concept of the slurry phase DME synthesis reactor.

Synthesis gas goes up as bubbles in the Slurry where catalyst powders are dispersing in inert medium oil. Synthesis gas, dissolving into the medium oil, reacts on the catalysts. Reaction heat is absorbed with the slurry having high heat capacity.

・Effective heat conductivity of the slurry is so high that homogeneous temperature distribution is realized without hot spot. Degradation of catalyst at local hot spot is avoided.

・Heat transfer coefficient between the slurry and heat exchanger tubes in the reactor is so high that heat removal from the reactor is done efficiently.

・Catalyst is demonstrated to be exchangeable during the operation.

・Standard operating condition is of 5MPa of pressure and 240-280℃ of temperature.

[3]Separation of produced DME

・By-produced water is so little that DME can be separated efficiently from un-reacted gas at chilled temperature.

・By-produced CO₂ is separated from un-reacted gas by being absorbed in DME.

Reference

 ”New Clean Fuel from Coal: Dimethyl Ether”
Preprints of Papers Presented at the 213th ACS National Meeting, San Francisco,(1997),Div. of Fuel Chemistry, P.705 [.pdf]

 ”An Ultra Clean New Fuel: Dimethyl Ether(DME)”
18th Congress of World Energy Council, Buenos Aires, Argentine,(2001),DS6 [.pdf]

 ”Slurry Phase DME Direct Synthesis Technology -100 ton/day Demonstration Plant Operation and Scale up Study-”
Proceedings of the 8th Natural Gas Conversion Symposium, Natal, Brazil, (2007), [Natural Gas Conversion VIII],Elsevier(2007),P.403 [.pdf]

 ”Slurry Phase Reactor Technology for DME Direct Synthesis”
International Journal of Chemical Reactor Engineering, 8(1),(2010) [.pdf]

 ”DME Production from Coal”, ”DME Production from Biomass”, ”DME Production from Renewable Power”
[DME Handbook Supplement],Japan DME Forum(2011), P.9, P.15, P.21 [.pdf]