Optimally designed reactive distillation processes for eco‐efficient production of ethyl levulinate

Abstract

BACKGROUND: Ethyl levulinate (EL) is an important chemical that can be used as a bio-based replacement of fuel additives such as methyl tert-butyl ether (MTBE) and tert-amyl methyl ether (TAME). EL production from lactic acid and ethanol is a viable option, as both precursors can be obtained from biomass. However, the problem of EL production by esterification is that this reaction is hindered by the chemical equilibrium limitations and the boiling points ranking, which is not the most favorable. RESULTS:This study provides novel optimally designed reactive distillation (RD) processes for the production of EL, taking into account costs, environmental impact and safety. The thermally coupled RD process is the most appealing, with the lowest energy use (1.667 MJ kg −1 EL), minimal investment cost, major energy savings (up to 54.3% lower than other RD processes), reduced environmental impact (up to 51% lower ECO99 index value) and similar safety as other RD processes considered (less than 2% differences in the individual risk (IR) indicator). CONCLUSION:The multi-objective optimization approach used here showed its robustness, practicality and flexibility to provide multiple optimal designs of intensified processes that are economically attractive, environmentally friendly and inherently safe. The first separation column (RC-1) performs the separation of water by-product as distillate from the main product (EL) and the unreacted LA. The second separation column (RC-2) wileyonlinelibrary.com/jctb Process optimizationThis study uses a multi-objective meta-heuristic optimization algorithm based on differential evolution and tabu list (MODE-TL), further details of which can be found elsewhere. 34 This algorithm allows the comparison of multiple solutions of optimized designs in the terms of multiple objective functions, described hereafter.

Production of levulinic acid and alkyl levulinates: a process insight

“…The advantages of RD are related to the continuous removal of products, pulling the chemical equilibrium towards the products, and particularly suitable for reactions hindered by the chemical equilibrium limitations, as esterification of LA to EL and other esters. 329,344 Vazquez-Castillo and his group designed a reactive distillation process which couples an RD column with two separation columns and leads to EL with a purity of 99.5 mol%; additionally, applying thermal coupling to RD, energy and cost reductions are in the range of 24-63 % and 8-43 %, respectively. 344 In literature, some works reported using pervaporation catalytic membrane reactor system (PVCMR) in which reaction and separation occur simultaneously, based on the permselective evaporation through the membrane.…”

Thermal coupled extractive distillation sequences with three entrainers for the separation of azeotrope isopropyl alcohol + diisopropyl ether

“…For designing and simulating the separation processes, a nonrandom two liquid (NRTL) model was adopted in this study. The feed compositions were set at 0.22:0.78 (azeotropic composition) and the feed flow rate was set at 100 kmol h –1 . The feed temperature and pressure were set at 320 K and 101.3 kPa, respectively .…”

“…The feed compositions were set at 0.22:0.78 (azeotropic composition) [36][37][38] and the feed flow rate was set at 100 kmol h -1 . [39][40][41] The feed temperature and pressure were set at 320 K and 101.3 kPa, respectively. 15 The purities of DIPE and IPA were set at 0.999 and 0.997 (mole fraction), respectively.…”

One-Pot Alcoholysis of the Lignocellulosic Eucalyptus nitens Biomass to n-Butyl Levulinate, a Valuable Additive for Diesel Motor Fuel

“…Levulinates can be synthesized by the esterification of pure LA with a simple equilibrium reaction, requiring a mild acid catalysis/reaction conditions, and generally affording very high yields towards the desired ester products. Both the reduced number of process units and the enhanced performances of new technological solutions, such as the reactive distillation, should allow significant improvements in the economics of the esterification process [10][11][12]. However, despite these ascertained potentials, the catalysis issue can be further improved, taking into account both the synthetic strategy and the adopted feedstock.…”