Process Development for Synthesis of Bio-Based Plasticizers

E3Tec and MSU are pursuing the commercialization of an integrated, energy-efficient process technology for the production of bio-based plasticizers.  Organic acids, typically produced by fermentation of carbohydrate feedstocks, constitute an important class of bio-renewable platform chemicals that can be further converted to useful products.  Bio-based plasticizers are currently gaining significant attention because they can be used in place of petroleum-based phthalate plasticizers that have shown to have health concerns in certain consumer products.  E3Tec received and recently completed US DOE SBIR Phase I and II projects.  The objective of the project was to design and evaluate processes using heat integrated reactive distillation (HIRD) with side reactors and PerVap membrane for esterification of organic acids.  The model chemical system studied in the SBIR project was esterification of citric acid with ethanol to produce tri-ethyl citrate (TEC).  ASPENPlus™ design method was developed and validated with the MSU pilot-scale test unit.  The process analysis is based on ASPENPlus™ integrated with validated rate-based models of side reactors.  The primary focus has been to develop a design methodology for rapid scale-up of bio-based processes.  The validated ASPENPlus™ design model is applied for synthesis of two leading bio-based plasticizer candidates, dioctyl adipate (DOA) and dioctyl succinate (DOSX).  Techno-economic merit comparisons based on C-Footprint, CAPEX, and OPEX for both the new and current commercial process technologies will be presented.