Evaluation of an integrated extraction process for in-situ phenol removal with micellar solutions of PEO-PPO-PEO block copolymers

Abstract

This paper evaluates the applicability of aqueous solutions of Pluronics for the removal of phenol in a separation and regeneration process. Experimental results show that Pluronic P103 micelles allow extraction of phenol from aqueous solutions at 30 °C. The phenol can be released due to the transition of the Pluronic micelles into unimers with a mild temperature switch from 30 to 8 °C. Ultrafiltration membranes provide a barrier between the aqueous Pluronic stripping solution and the aqueous solution in a (bio)reactor containing the desired product. Additionally, a similar UF membrane is used to separate the micelles and unimers from water. Steady state model analysis of the proposed separation and regeneration process are performed to obtain a phenol mass flow rate in the product stream equal to the phenol production rate in the (bio)reactor. Furthermore, the process is analyzed for different process configurations and a cost estimation is made. The results show that for the model product phenol, the process costs are mainly determined by the required membrane area. The proposed process can be suited for products that allow for a higher critical concentration in the (bio)reactor as compared to phenol. The resulting higher driving force for membrane extraction will result in a decrease of the overall process costs. For products with a lower solubility in water, recovery is easy after regeneration of the micellar solvent.