Butane Isomerization Isomalk-3

Isomalk-3 process for normal butane isomerization to isobutane is based on long-term experience of SIE Neftehim, LLC in the field of light paraffin hydrocarbons isomerization. Basis of Isomalk-3 process is sulfated oxide catalyst SI-3, which has high tolerance to sulfur impurities and can be operated without pre-hydrotreatment of butane fraction. High tolerance of the catalyst to catalytic poisons impurities ensures longer service cycle. Besides, absence of aggressive reactants reduces corrosion of equipment and totally excludes generation of wastes to be utilized.

Isomalk-3 technology over SI-3 catalyst has a number of important advantages over technologies based on chlorinated catalysts:

  • chlorinated agents supply is not required and accordingly dry gas alkali treatment section is absent;
  • due to absence of aggressive agents, corrosion-proof materials are not required and there are no wastes that require utilization or disposal;
  • the catalyst is tolerant to the action of sulfur, nitrogen and water; process upsets do not cause irreversible activity loss, which allows its operation without preliminary feed hydrotreatment;
  • high tolerance of the catalyst to catalytic poisons’ impurities ensures long service cycle, and its ability to regenerate ensures service life of not less than 8 years.


SI-3 catalyst specifications and Isomalk-3 technology parameters


Typical Isomalk-3 n-butane isomerization unit consists of the following sections:

  • isomerization feed treatment and drying section – is designed for water removal from isomerization feed; this procedure is intended for catalyst protection from water, which inhibits catalyst activity;
  • isomerization reactor section – is designed for proceeding isomerization reactions of normal butane into isobutane over active catalyst sites at the most favorable conditions for the main reaction;
  • hydrogen gas dryers section – is designed for water removal from hydrogen gas, as well as from nitrogen during catalyst regeneration;
  • stabilizer section – is designed for recovery of C1-C3 hydrocarbons and dissolved hydrogen from the product.

N-butane isomerization

Long term work experience of SIE Neftehim, LLC as the engineering and design organization allows ensuring effective work optimization and timely troubleshooting of the unit operation.

Normal butane isomerization unit with deisobutanization column is now being designed by Isomalk-3 technology in Dongying, China.

SIE NEFTEHIM, LLC guarantees providing technical documentation (guidelines) for catalyst loading, activation, start-up, normal operation, shut-down, catalyst regeneration and unloading, recommendations on analytical control of the process.

SIE Neftehim, LLC will render technical assistance directly at the unit site for catalyst reactor charge, initial unit start-up, as well as in scheduled turnaround and catalyst regeneration. Monitoring and technical assistance are rendered during the total service life of the catalyst.