CDTECH, a part of Lummus Technology, has developed an array of patented etherification technologies for the production of high-quality ethers, which are blended into gasoline to boost octane and/or meet oxygenate requirements of reformulated fuels. These processes are based on the unique catalytic distillation process, which combines reaction and fractionation in a single unit operation, not only reducing investment cost, but allowing reactant conversion beyond equilibrium values.

The etherification processes are based on a minimum two-reactor design where one is a boiling-point fixed-bed reactor followed by final conversion in a catalytic distillation column. Both of these reactors utilize an acidic ion exchange resin catalyst.

ETBE is formed by the catalytic etherification of isobutylene with ethanol. The CDEtbe⁽¹⁾ process uses C₄ streams from steam cracker and isobutane dehydrogenation units to produce ETBE.

Tertiary Amyl Ethyl Ether (TAEE) is formed by the catalytic etherification of isoamylene with ethanol. The CDTaee⁽¹⁾ process uses C₅ streams from refinery units to produce TAEE.

MTBE is formed by the catalytic etherification of isobutylene with methanol. The CDMtbe⁽¹⁾process uses C₄ streams from steam cracker or isobutane dehydrogenation units to produce MTBE.

TAME is formed by the catalytic etherification of isoamylene with methanol. The CDTECH process use C₅ streams from refinery units.

• The CDTame⁽¹⁾ process utilizes the standard catalytic distillation system.
• The CDEtherol⁽¹⁾ process is used when there are multiple C₅ feedstock sources that require hydrotreating. This process requires an additional lead reactor that contains a proprietary trifunctional catalyst to provide selective hydrogenation of diolefins, isomerization of 3 methylbutene-1 to 2 methylbutene-2, and etherification of isoamylene.
• The CDIsotame⁽¹⁾ process combines skeletal isomerization and etherification steps to maximize the production of TAME from refinery and steam cracker C₅ streams. Skeletal isomerization converts normal amylenes to isoamylenes in an olefinic C₅ stream.

The CDEthers⁽¹⁾ process coproduces MTBE and TAME by the catalytic etherification of isobutylene and isoamylene (using refinery C₄/C₅ streams) with methanol.

(1) These process names are registered trademarks of CDTECH.