NExETHERS™


    NExETHERS™

    NExETHERS™ process_Areal viewNExETHERS™ is the ultimate technology for the combined production of MTBE, TAME and heavier ethers in one unit.

    The process achieves a significant increase in iso-olefin conversion by combining alcohol recovery and circulation with oxygenate removal. The resulting high yield of gasoline ethers, almost total conversion of methanol and simultaneous purification of the C4 stream for alkylation feedstock offers refiners a truly profitable opportunity to maximize oxygenate production. No additional equipment is required for processing ethanol.

     

    Process Description

    NExETHERS™ process

    In the NExETHERS process, tertiary isoolefins and methanol react in the presence of a catalyst, typically a commercial cation exchange resin. Tertiary C4 olefin forms MTBE, tertiary C5 olefins TAME, tertiary C6 olefins THxME (Tertiary Hexyl Methyl Ethers), and tertiary C7 olefins form THpME (Tertiary Heptyl Methyl Ethers). Ethanol will produce ethyl ethers. Reactor effluent goes to the primary fractionator which separates ether product and heavy hydrocarbons (C5s and heavier) from unreacted C4 hydrocarbons and lighter components. Most of the methanol and the unreacted isoolefins are recycled to the reactors via a side-draw. Remaining methanol and light oxygenates (dimethyl ether and water) are included in the overhead product.

    The second fractionating tower serves a dual purpose: Its most important function is the near-total recovery of unreacted feed alcohol which is returned to the reactor section with unreacted isobutylene to enhance the conversion for both components. Simultaneously, alcohol and all light oxygenates are removed from the C4 stream which is the bottom product of the distillation column. There is no need for a separate oxygenate removal unit upstream e.g. alkylation. Because the overhead stream contains only an azeotropic amount of alcohol, an almost complete conversion of feed alcohol is obtained.

    Advantages

    • Extremely high MTBE/ETBE, TAME/TAEE, THxME/THxEE and THpME/THpEE yield at low cost, using low maintenance equipment.
    • Individually controlled reactor temperatures ensure high ether yield with minimal side product formation.
    • Conventional catalysts available from several sources, need no complex loading.
    • The ultimate integration of methanol recovery and oxygenates removal - essentially total methanol conversion with no additional costs for alkylation feed treatment.
    • Complete freedom to choose between methanol and ethanol.
    • No need to shut-down the unit during catalyst change.

    Conversions

    NExETHERS™ Conversions

    For further information, please contact us:

    mailto: info.nestejacobs@nesteoil.com
    Neste Jacobs Oy
    POB 310
    FIN-06101 Porvoo
    Finland
    Tel +358 10 45811
    Fax +358 10 458 7221