Techno-economic evaluation of an ultrasound-assisted Enzymatic Reactive Distillation process

Abstract

18Enzymatic Reactive Distillation (ERD) is a bioreactive process, in which enzymes are 19 immobilized on column internal surface, and helps to overcome chemical reaction and phase 20 equilibrium limitations. The activation of enzymes by ultrasound (US) leads to ultrasound-21 assisted ERD (US-ERD) which might display more eco-efficiency than standard processing 22 of valuable chemicals. Reaction rate improvements of more than 50% could be achieved by 23 the assistance of US. 24An US-ERD process for the synthesis of butyl butyrate (10 kilotons per year, 99 wt% purity) 25 was designed. A techno-economic evaluation via process optimization was carried out to 26 minimize the annual costs, by using an evolutionary algorithm. The techno-economic 27 evaluation shows that the US-ERD process and the ERD share nearly equal costs. Installation 28 costs of the US equipment are high but they are compensated by a 12% lower reactive section 29 height and a 7% lower total height of the US-ERD column in comparison to ERD. 30 31

Ultrasound‐assisted emerging technologies for chemical processes

“…As the techno economic evaluation presented by Wierschem et al . shows a significant increase in the reaction rate by US application compared with the unsonicated process does not necessarily lead to cost savings. Therefore, a clear benefit of US application needs to be found prior to its use. Phase 6: introduction in production at large scale.…”

“…Ultrasound has been shown to be able to accelerate the reaction rates of electrochemical, chemical and enzyme‐catalyzed reactions . The possible implementation requirements of alternative energy forms (as US) in RD were recently shown on the basis of the enzyme‐catalyzed transesterification of ethyl butyrate . The combination of US, RD and enzyme‐catalyzed reactions leads to synergies, which can improve process economics in the case of high reaction rate improvement.…”

“…Based on the developed model a model‐based investigation can be performed in order to analyze the potential benefits of an optimization‐based design study for a certain production scenario. Wierschem et al . performed such an analysis for an industrial‐scale ERD and US‐ERD process, considering the synthesis of 10 kilotons of butyl butyrate per year with a desired purity of 99 wt%.…”

“…Techno economic evaluations as presented by Wierschem et al . are indispensable in order to analyze if the tremendous improvements of the reaction rates by US application reported in literature, can be sufficiently exploited in US‐assisted RD/ERD.…”

“…30,31 The possible implementation requirements of alternative energy forms (as US) in RD were recently shown on the basis of the enzyme-catalyzed transesterification of ethyl butyrate. 32 The combination of US, RD and enzyme-catalyzed reactions leads to synergies, which can improve process economics in the case of high reaction rate improvement. Nevertheless, several measures are necessary before industrial implementation, which are discussed hereafter.…”