(673h) Comparative Assessment of Traditional and Intensified Process Configurations for Isopropyl Myristate Production

Isopropyl myristate (IPM) is a versatile fatty ester mainly used in the cosmetics and
fragrance industry as emollient, lubricant, binding agent and fragrance fixative. Due to the
paramount importance of this oleochemical product, different techniques have been
evaluated to overcome processing challenges. IPM is mainly produced via esterification of
myristic acid (MA) with isopropanol (IPA) using homogeneous or heterogeneous catalysts
and generating water (W) as by-product. Compatibility among reactants must be enhance
because MA is solid below 54 C, there is a limited solubility of MA in IPA [1,2], and as in
most esterification, reaction conversion is limited by chemical equilibrium. As a result,
excess IPA is normally used in reaction and its recovery and recycle is complex because it
forms an azeotropic mixture with water. Additionally, extraction of MA traces from IPM is
generally carried out by neutralization, generating waste and reducing process efficiency.
Additionally, the reaction is normally carried out at high temperatures using homogeneous
and heterogeneous catalysts [3, 4], thus requiring high pressure operation. Considering
the side reactions promoted with strong acidic homogeneous catalysts under these
conditions (e.g. etherification of IPA), researchers keep exploring new heterogeneous
catalysts to improve activity, selectivity and process performance [5].
To overcome some of the previously described challenges, different process
configurations have been proposed for the continuous esterification of fatty acids [6].
These have included from single reactor-decanter systems, reactor(s) coupled to
condenser(s), reactor coupled to a fractionating column, reactor followed by a distillation
train, and hybrid and intensified processes such as reactive distillation (RD) and extractive-
enhanced RD. The lasts have been explored experimentally in the synthesis of IPM [7-9].
To improve the existing processes, entrainer-based RD [10] and auto-extractive RD [11]
have been also proposed. Nonetheless, from the large set of potential process
configurations to intensify the production of IPM, there is not a systematic comparison to
identify which could be considered suitable for a further industrial implementation.
In this regard, this work developed a systematic evaluation of different classical and
intensified IPM production schemes and a subsequent optimization using key financial
indicators. Evaluation of the processes was done using validated thermodynamic [2] and
kinetic [3, 4] models. Processes were simulated under steady in Aspen Plus V.11, and the
optimization was performed using stochastic methods by connecting the process simulator
with Python. The modeling included the downstream purification of IPA and its recycling to
the corresponding reactor. As expected, reported intensified technologies provided better

performance with large energy savings in the process compared with traditional reactor-
decanter and reactor-columns configurations. Nonetheless, RD configurations had to
operate under high pressure to achieve suitable temperatures and high reaction rates to
reduce the required holdups. This enabled to reduce the size of the column and the
corresponding costs. The selected configuration could be used as benchmark for further
assessment of novel processes for IPM production.

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